UI: Entities data query

@@ -22,22 +22,6 @@
       }
     },
     {
-      "alias": "entities_table",
-      "name": "Entities table",
-      "descriptor": {
-        "type": "latest",
-        "sizeX": 7.5,
-        "sizeY": 6.5,
-        "resources": [],
-        "templateHtml": "<tb-entities-table-widget \n    [ctx]=\"ctx\">\n</tb-entities-table-widget>",
-        "templateCss": "",
-        "controllerScript": "self.onInit = function() {\n}\n\nself.onDataUpdated = function() {\n    self.ctx.$scope.entitiesTableWidget.onDataUpdated();\n}\n\nself.typeParameters = function() {\n    return {\n        maxDatasources: 1,\n        dataKeysOptional: true\n    };\n}\n\nself.actionSources = function() {\n    return {\n        'actionCellButton': {\n            name: 'widget-action.action-cell-button',\n            multiple: true\n        },\n        'rowClick': {\n            name: 'widget-action.row-click',\n            multiple: false\n        },\n        'rowDoubleClick': {\n            name: 'widget-action.row-double-click',\n            multiple: false\n        }\n    };\n}\n\nself.onDestroy = function() {\n}\n",
-        "settingsSchema": "{\n    \"schema\": {\n        \"type\": \"object\",\n        \"title\": \"EntitiesTableSettings\",\n        \"properties\": {\n            \"entitiesTitle\": {\n                \"title\": \"Entities table title\",\n                \"type\": \"string\",\n                \"default\": \"\"\n            },\n            \"enableSearch\": {\n                \"title\": \"Enable entities search\",\n                \"type\": \"boolean\",\n                \"default\": true\n            },\n            \"enableSelectColumnDisplay\": {\n                \"title\": \"Enable select columns to display\",\n                \"type\": \"boolean\",\n                \"default\": true\n            },\n            \"displayEntityName\": {\n                \"title\": \"Display entity name column\",\n                \"type\": \"boolean\",\n                \"default\": true\n            },\n            \"entityNameColumnTitle\": {\n                \"title\": \"Entity name column title\",\n                \"type\": \"string\",\n                \"default\": \"\"\n            },\n            \"displayEntityLabel\": {\n                \"title\": \"Display entity label column\",\n                \"type\": \"boolean\",\n                \"default\": false\n            },\n            \"entityLabelColumnTitle\": {\n                \"title\": \"Entity label column title\",\n                \"type\": \"string\",\n                \"default\": \"\"\n            },\n            \"displayEntityType\": {\n                \"title\": \"Display entity type column\",\n                \"type\": \"boolean\",\n                \"default\": true\n            },\n            \"displayPagination\": {\n                \"title\": \"Display pagination\",\n                \"type\": \"boolean\",\n                \"default\": true\n            },\n            \"defaultPageSize\": {\n                \"title\": \"Default page size\",\n                \"type\": \"number\",\n                \"default\": 10\n            },\n            \"defaultSortOrder\": {\n                \"title\": \"Default sort order\",\n                \"type\": \"string\",\n                \"default\": \"entityName\"\n            }\n        },\n        \"required\": []\n    },\n    \"form\": [\n        \"entitiesTitle\",\n        \"enableSearch\",\n        \"enableSelectColumnDisplay\",\n        \"displayEntityName\",\n        \"entityNameColumnTitle\",\n        \"displayEntityLabel\",\n        \"entityLabelColumnTitle\",\n        \"displayEntityType\",\n        \"displayPagination\",\n        \"defaultPageSize\",\n        \"defaultSortOrder\"\n    ]\n}",
-        "dataKeySettingsSchema": "{\n    \"schema\": {\n        \"type\": \"object\",\n        \"title\": \"DataKeySettings\",\n        \"properties\": {\n            \"columnWidth\": {\n                \"title\": \"Column width (px or %)\",\n                \"type\": \"string\",\n                \"default\": \"0px\"\n            },\n            \"useCellStyleFunction\": {\n                \"title\": \"Use cell style function\",\n                \"type\": \"boolean\",\n                \"default\": false\n            },\n            \"cellStyleFunction\": {\n                \"title\": \"Cell style function: f(value)\",\n                \"type\": \"string\",\n                \"default\": \"\"\n            },\n            \"useCellContentFunction\": {\n                \"title\": \"Use cell content function\",\n                \"type\": \"boolean\",\n                \"default\": false\n            },\n            \"cellContentFunction\": {\n                \"title\": \"Cell content function: f(value, entity, ctx)\",\n                \"type\": \"string\",\n                \"default\": \"\"\n            }\n        },\n        \"required\": []\n    },\n    \"form\": [\n        \"columnWidth\",\n        \"useCellStyleFunction\",\n        {\n            \"key\": \"cellStyleFunction\",\n            \"type\": \"javascript\"\n        },\n        \"useCellContentFunction\",\n        {\n            \"key\": \"cellContentFunction\",\n            \"type\": \"javascript\"\n        }\n    ]\n}",
-        "defaultConfig": "{\"timewindow\":{\"realtime\":{\"interval\":1000,\"timewindowMs\":86400000},\"aggregation\":{\"type\":\"NONE\",\"limit\":200}},\"showTitle\":true,\"backgroundColor\":\"rgb(255, 255, 255)\",\"color\":\"rgba(0, 0, 0, 0.87)\",\"padding\":\"4px\",\"settings\":{\"enableSelection\":true,\"enableSearch\":true,\"displayDetails\":true,\"displayPagination\":true,\"defaultPageSize\":10,\"defaultSortOrder\":\"entityName\",\"displayEntityName\":true,\"displayEntityType\":true},\"title\":\"Entities table\",\"dropShadow\":true,\"enableFullscreen\":true,\"titleStyle\":{\"fontSize\":\"16px\",\"fontWeight\":400,\"padding\":\"5px 10px 5px 10px\"},\"useDashboardTimewindow\":false,\"showLegend\":false,\"datasources\":[{\"type\":\"function\",\"name\":\"Simulated\",\"dataKeys\":[{\"name\":\"f(x)\",\"type\":\"function\",\"label\":\"Sin\",\"color\":\"#2196f3\",\"settings\":{\"columnWidth\":\"0px\",\"useCellStyleFunction\":false,\"cellStyleFunction\":\"\",\"useCellContentFunction\":false,\"cellContentFunction\":\"\"},\"_hash\":0.472295003170325,\"funcBody\":\"return Math.round(1000*Math.sin(time/5000));\"},{\"name\":\"f(x)\",\"type\":\"function\",\"label\":\"Cos\",\"color\":\"#4caf50\",\"settings\":{\"columnWidth\":\"0px\",\"useCellStyleFunction\":false,\"cellStyleFunction\":\"\",\"useCellContentFunction\":false,\"cellContentFunction\":\"\"},\"_hash\":0.8926244886945558,\"funcBody\":\"return Math.round(1000*Math.cos(time/5000));\"},{\"name\":\"f(x)\",\"type\":\"function\",\"label\":\"Random\",\"color\":\"#f44336\",\"settings\":{\"columnWidth\":\"0px\",\"useCellStyleFunction\":false,\"cellStyleFunction\":\"\",\"useCellContentFunction\":false,\"cellContentFunction\":\"\"},\"_hash\":0.6401141393938932,\"funcBody\":\"var value = prevValue + Math.random() * 100 - 50;\\nvar multiplier = Math.pow(10, 2 || 0);\\nvar value = Math.round(value * multiplier) / multiplier;\\nif (value < -1000) {\\n\\tvalue = -1000;\\n} else if (value > 1000) {\\n\\tvalue = 1000;\\n}\\nreturn value;\"}]}]}"
-      }
-    },
-    {
       "alias": "html_card",
       "name": "HTML Card",
       "descriptor": {
@@ -132,6 +116,22 @@
         "dataKeySettingsSchema": "{\n    \"schema\": {\n        \"type\": \"object\",\n        \"title\": \"DataKeySettings\",\n        \"properties\": {},\n        \"required\": []\n    },\n    \"form\": []\n}",
         "defaultConfig": "{\"timewindow\":{\"realtime\":{\"interval\":1000,\"timewindowMs\":86400000},\"aggregation\":{\"type\":\"NONE\",\"limit\":200}},\"showTitle\":true,\"backgroundColor\":\"rgb(255, 255, 255)\",\"color\":\"rgba(0, 0, 0, 0.87)\",\"padding\":\"4px\",\"settings\":{\"nodeRelationQueryFunction\":\"/**\\n\\n// Function should return relations query object for current node used to fetch entity children.\\n// Function can return 'default' string value. In this case default relations query will be used.\\n\\n// The following example code will construct simple relations query that will fetch relations of type 'Contains'\\n// from the current entity.\\n\\nvar entity = nodeCtx.entity;\\nvar query = {\\n    parameters: {\\n        rootId: entity.id.id,\\n        rootType: entity.id.entityType,\\n        direction: types.entitySearchDirection.from,\\n        relationTypeGroup: \\\"COMMON\\\",\\n        maxLevel: 1\\n    },\\n    filters: [{\\n        relationType: \\\"Contains\\\",\\n        entityTypes: []\\n    }]\\n};\\nreturn query;\\n\\n**/\\n\",\"nodeHasChildrenFunction\":\"/**\\n\\n// Function should return boolean value indicating whether current node has children (whether it can be expanded).\\n\\n// The following example code will restrict entities hierarchy expansion up to third level.\\n\\nreturn nodeCtx.level <= 2;\\n\\n// The next example code will restrict entities expansion according to the value of example 'nodeHasChildren' attribute.\\n\\nvar data = nodeCtx.data;\\nif (data.hasOwnProperty('nodeHasChildren') && data['nodeHasChildren'] !== null) {\\n    return data['nodeHasChildren'] === 'true';\\n} else {\\n    return true;\\n}\\n  \\n**/\\n \",\"nodeTextFunction\":\"/**\\n\\n// Function should return text (can be HTML code) for the current node.\\n\\n// The following example code will generate node text consisting of entity name and temperature if temperature value is present in entity attributes/timeseries.\\n\\nvar data =  nodeCtx.data;\\nvar entity = nodeCtx.entity;\\nvar text = entity.name;\\nif (data.hasOwnProperty('temperature') && data['temperature'] !== null) {\\n    text += \\\" <b>\\\"+ data['temperature'] +\\\" °C</b>\\\";\\n}\\nreturn text;\\n\\n**/\",\"nodeIconFunction\":\"/** \\n\\n// Function should return node icon info object.\\n// Resulting object should contain either 'materialIcon' or 'iconUrl' property. \\n// Where:\\n    - 'materialIcon' - name of the material icon to be used from the Material Icons Library (https://material.io/tools/icons);\\n    - 'iconUrl' - url of the external image to be used as node icon.\\n// Function can return 'default' string value. In this case default icons according to entity type will be used.\\n\\n// The following example code shows how to use external image for devices which name starts with 'Test' and use \\n// default icons for the rest of entities.\\n\\nvar entity = nodeCtx.entity;\\nif (entity.id.entityType === 'DEVICE' && entity.name.startsWith('Test')) {\\n    return {iconUrl: 'https://avatars1.githubusercontent.com/u/14793288?v=4&s=117'};\\n} else {\\n    return 'default';\\n}\\n \\n**/\",\"nodeDisabledFunction\":\"/**\\n\\n// Function should return boolean value indicating whether current node should be disabled (not selectable).\\n\\n// The following example code will disable current node according to the value of example 'nodeDisabled' attribute.\\n\\nvar data = nodeCtx.data;\\nif (data.hasOwnProperty('nodeDisabled') && data['nodeDisabled'] !== null) {\\n    return data['nodeDisabled'] === 'true';\\n} else {\\n    return false;\\n}\\n  \\n**/\\n\",\"nodesSortFunction\":\"/**\\n\\n// This function is used to sort nodes of the same level. Function should compare two nodes and return \\n// integer value: \\n//     - less than 0 - sort nodeCtx1 to an index lower than nodeCtx2\\n//     - 0 - leave nodeCtx1 and nodeCtx2 unchanged with respect to each other\\n//     - greater than 0 - sort nodeCtx2 to an index lower than nodeCtx1\\n\\n// The following example code will sort entities first by entity type in alphabetical order then\\n// by entity name in alphabetical order.\\n\\nvar result = nodeCtx1.entity.id.entityType.localeCompare(nodeCtx2.entity.id.entityType);\\nif (result === 0) {\\n    result = nodeCtx1.entity.name.localeCompare(nodeCtx2.entity.name);\\n}\\nreturn result;\\n  \\n**/\",\"nodeOpenedFunction\":\"/**\\n\\n// Function should return boolean value indicating whether current node should be opened (expanded) when it first loaded.\\n\\n// The following example code will open by default nodes up to third level.\\n\\nreturn nodeCtx.level <= 2;\\n\\n**/\\n \"},\"title\":\"Entities hierarchy\",\"dropShadow\":true,\"enableFullscreen\":true,\"titleStyle\":{\"fontSize\":\"16px\",\"fontWeight\":400,\"padding\":\"5px 10px 5px 10px\"},\"useDashboardTimewindow\":false,\"showLegend\":false,\"datasources\":[{\"type\":\"function\",\"name\":\"Simulated\",\"dataKeys\":[{\"name\":\"f(x)\",\"type\":\"function\",\"label\":\"Sin\",\"color\":\"#2196f3\",\"settings\":{\"columnWidth\":\"0px\",\"useCellStyleFunction\":false,\"cellStyleFunction\":\"\",\"useCellContentFunction\":false,\"cellContentFunction\":\"\"},\"_hash\":0.472295003170325,\"funcBody\":\"return Math.round(1000*Math.sin(time/5000));\"},{\"name\":\"f(x)\",\"type\":\"function\",\"label\":\"Cos\",\"color\":\"#4caf50\",\"settings\":{\"columnWidth\":\"0px\",\"useCellStyleFunction\":false,\"cellStyleFunction\":\"\",\"useCellContentFunction\":false,\"cellContentFunction\":\"\"},\"_hash\":0.8926244886945558,\"funcBody\":\"return Math.round(1000*Math.cos(time/5000));\"},{\"name\":\"f(x)\",\"type\":\"function\",\"label\":\"Random\",\"color\":\"#f44336\",\"settings\":{\"columnWidth\":\"0px\",\"useCellStyleFunction\":false,\"cellStyleFunction\":\"\",\"useCellContentFunction\":false,\"cellContentFunction\":\"\"},\"_hash\":0.6401141393938932,\"funcBody\":\"var value = prevValue + Math.random() * 100 - 50;\\nvar multiplier = Math.pow(10, 2 || 0);\\nvar value = Math.round(value * multiplier) / multiplier;\\nif (value < -1000) {\\n\\tvalue = -1000;\\n} else if (value > 1000) {\\n\\tvalue = 1000;\\n}\\nreturn value;\"}]}],\"widgetStyle\":{},\"actions\":{}}"
       }
+    },
+    {
+      "alias": "entities_table",
+      "name": "Entities table",
+      "descriptor": {
+        "type": "latest",
+        "sizeX": 7.5,
+        "sizeY": 6.5,
+        "resources": [],
+        "templateHtml": "<tb-entities-table-widget \n    [ctx]=\"ctx\">\n</tb-entities-table-widget>",
+        "templateCss": "",
+        "controllerScript": "self.onInit = function() {\n}\n\nself.onDataUpdated = function() {\n    self.ctx.$scope.entitiesTableWidget.onDataUpdated();\n}\n\nself.typeParameters = function() {\n    return {\n        maxDatasources: 1,\n        hasDataPageLink: true,\n        dataKeysOptional: true\n    };\n}\n\nself.actionSources = function() {\n    return {\n        'actionCellButton': {\n            name: 'widget-action.action-cell-button',\n            multiple: true\n        },\n        'rowClick': {\n            name: 'widget-action.row-click',\n            multiple: false\n        },\n        'rowDoubleClick': {\n            name: 'widget-action.row-double-click',\n            multiple: false\n        }\n    };\n}\n\nself.onDestroy = function() {\n}\n",
+        "settingsSchema": "{\n    \"schema\": {\n        \"type\": \"object\",\n        \"title\": \"EntitiesTableSettings\",\n        \"properties\": {\n            \"entitiesTitle\": {\n                \"title\": \"Entities table title\",\n                \"type\": \"string\",\n                \"default\": \"\"\n            },\n            \"enableSearch\": {\n                \"title\": \"Enable entities search\",\n                \"type\": \"boolean\",\n                \"default\": true\n            },\n            \"enableSelectColumnDisplay\": {\n                \"title\": \"Enable select columns to display\",\n                \"type\": \"boolean\",\n                \"default\": true\n            },\n            \"displayEntityName\": {\n                \"title\": \"Display entity name column\",\n                \"type\": \"boolean\",\n                \"default\": true\n            },\n            \"entityNameColumnTitle\": {\n                \"title\": \"Entity name column title\",\n                \"type\": \"string\",\n                \"default\": \"\"\n            },\n            \"displayEntityLabel\": {\n                \"title\": \"Display entity label column\",\n                \"type\": \"boolean\",\n                \"default\": false\n            },\n            \"entityLabelColumnTitle\": {\n                \"title\": \"Entity label column title\",\n                \"type\": \"string\",\n                \"default\": \"\"\n            },\n            \"displayEntityType\": {\n                \"title\": \"Display entity type column\",\n                \"type\": \"boolean\",\n                \"default\": true\n            },\n            \"displayPagination\": {\n                \"title\": \"Display pagination\",\n                \"type\": \"boolean\",\n                \"default\": true\n            },\n            \"defaultPageSize\": {\n                \"title\": \"Default page size\",\n                \"type\": \"number\",\n                \"default\": 10\n            },\n            \"defaultSortOrder\": {\n                \"title\": \"Default sort order\",\n                \"type\": \"string\",\n                \"default\": \"entityName\"\n            }\n        },\n        \"required\": []\n    },\n    \"form\": [\n        \"entitiesTitle\",\n        \"enableSearch\",\n        \"enableSelectColumnDisplay\",\n        \"displayEntityName\",\n        \"entityNameColumnTitle\",\n        \"displayEntityLabel\",\n        \"entityLabelColumnTitle\",\n        \"displayEntityType\",\n        \"displayPagination\",\n        \"defaultPageSize\",\n        \"defaultSortOrder\"\n    ]\n}",
+        "dataKeySettingsSchema": "{\n    \"schema\": {\n        \"type\": \"object\",\n        \"title\": \"DataKeySettings\",\n        \"properties\": {\n            \"columnWidth\": {\n                \"title\": \"Column width (px or %)\",\n                \"type\": \"string\",\n                \"default\": \"0px\"\n            },\n            \"useCellStyleFunction\": {\n                \"title\": \"Use cell style function\",\n                \"type\": \"boolean\",\n                \"default\": false\n            },\n            \"cellStyleFunction\": {\n                \"title\": \"Cell style function: f(value)\",\n                \"type\": \"string\",\n                \"default\": \"\"\n            },\n            \"useCellContentFunction\": {\n                \"title\": \"Use cell content function\",\n                \"type\": \"boolean\",\n                \"default\": false\n            },\n            \"cellContentFunction\": {\n                \"title\": \"Cell content function: f(value, entity, ctx)\",\n                \"type\": \"string\",\n                \"default\": \"\"\n            }\n        },\n        \"required\": []\n    },\n    \"form\": [\n        \"columnWidth\",\n        \"useCellStyleFunction\",\n        {\n            \"key\": \"cellStyleFunction\",\n            \"type\": \"javascript\"\n        },\n        \"useCellContentFunction\",\n        {\n            \"key\": \"cellContentFunction\",\n            \"type\": \"javascript\"\n        }\n    ]\n}",
+        "defaultConfig": "{\"timewindow\":{\"realtime\":{\"interval\":1000,\"timewindowMs\":86400000},\"aggregation\":{\"type\":\"NONE\",\"limit\":200}},\"showTitle\":true,\"backgroundColor\":\"rgb(255, 255, 255)\",\"color\":\"rgba(0, 0, 0, 0.87)\",\"padding\":\"4px\",\"settings\":{\"enableSelection\":true,\"enableSearch\":true,\"displayDetails\":true,\"displayPagination\":true,\"defaultPageSize\":10,\"defaultSortOrder\":\"entityName\",\"displayEntityName\":true,\"displayEntityType\":true},\"title\":\"Entities table\",\"dropShadow\":true,\"enableFullscreen\":true,\"titleStyle\":{\"fontSize\":\"16px\",\"fontWeight\":400,\"padding\":\"5px 10px 5px 10px\"},\"useDashboardTimewindow\":false,\"showLegend\":false,\"datasources\":[{\"type\":\"function\",\"name\":\"Simulated\",\"dataKeys\":[{\"name\":\"f(x)\",\"type\":\"function\",\"label\":\"Sin\",\"color\":\"#2196f3\",\"settings\":{\"columnWidth\":\"0px\",\"useCellStyleFunction\":false,\"cellStyleFunction\":\"\",\"useCellContentFunction\":false,\"cellContentFunction\":\"\"},\"_hash\":0.472295003170325,\"funcBody\":\"return Math.round(1000*Math.sin(time/5000));\"},{\"name\":\"f(x)\",\"type\":\"function\",\"label\":\"Cos\",\"color\":\"#4caf50\",\"settings\":{\"columnWidth\":\"0px\",\"useCellStyleFunction\":false,\"cellStyleFunction\":\"\",\"useCellContentFunction\":false,\"cellContentFunction\":\"\"},\"_hash\":0.8926244886945558,\"funcBody\":\"return Math.round(1000*Math.cos(time/5000));\"},{\"name\":\"f(x)\",\"type\":\"function\",\"label\":\"Random\",\"color\":\"#f44336\",\"settings\":{\"columnWidth\":\"0px\",\"useCellStyleFunction\":false,\"cellStyleFunction\":\"\",\"useCellContentFunction\":false,\"cellContentFunction\":\"\"},\"_hash\":0.6401141393938932,\"funcBody\":\"var value = prevValue + Math.random() * 100 - 50;\\nvar multiplier = Math.pow(10, 2 || 0);\\nvar value = Math.round(value * multiplier) / multiplier;\\nif (value < -1000) {\\n\\tvalue = -1000;\\n} else if (value > 1000) {\\n\\tvalue = 1000;\\n}\\nreturn value;\"}]}]}"
+      }
     }
   ]
 }
\ No newline at end of file

@@ -452,7 +452,7 @@ public class DefaultEntityQueryRepository implements EntityQueryRepository {
     }
 
     private String entityNameQuery(EntityNameFilter filter) {
-        return String.format("lower(e.search_text) like lower(concat(%s, '%%'))", filter.getEntityNameFilter());
+        return String.format("lower(e.search_text) like lower(concat('%s', '%%'))", filter.getEntityNameFilter());
     }
 
     private String typeQuery(EntityFilter filter) {

@@ -48,6 +48,7 @@ public class EntityKeyMapping {
 
     static {
         entityFieldColumnMap.put("createdTime", "id");
+        entityFieldColumnMap.put("entityType", "entity_type");
         entityFieldColumnMap.put("name", "name");
         entityFieldColumnMap.put("type", "type");
         entityFieldColumnMap.put("label", "label");

@@ -22,8 +22,8 @@ import { EntityService } from '@core/http/entity.service';
 import { UtilsService } from '@core/services/utils.service';
 import { AliasFilterType, EntityAliases } from '@shared/models/alias.models';
 import { EntityInfo } from '@shared/models/entity.models';
-import { map } from 'rxjs/operators';
-import { defaultEntityDataPageLink } from '@shared/models/query/query.models';
+import { map, mergeMap } from 'rxjs/operators';
+import { createDefaultEntityDataPageLink, defaultEntityDataPageLink } from '@shared/models/query/query.models';
 
 export class AliasController implements IAliasController {
 
@@ -169,7 +169,24 @@ export class AliasController implements IAliasController {
     }
   }
 
-  private resolveDatasource(datasource: Datasource, isSingle?: boolean): Observable<Array<Datasource>> {
+  resolveSingleEntityInfo(aliasId: string): Observable<EntityInfo> {
+    return this.getAliasInfo(aliasId).pipe(
+      mergeMap((aliasInfo) => {
+        if (aliasInfo.resolveMultiple) {
+          if (aliasInfo.entityFilter) {
+            return this.entityService.findSingleEntityInfoByEntityFilter(aliasInfo.entityFilter,
+              {ignoreLoading: true, ignoreErrors: true});
+          } else {
+            return of(null);
+          }
+        } else {
+          return of(aliasInfo.currentEntity);
+        }
+      })
+    );
+  }
+
+  private resolveDatasource(datasource: Datasource, isSingle?: boolean): Observable<Datasource> {
     if (datasource.type === DatasourceType.entity) {
       if (datasource.entityAliasId) {
         return this.getAliasInfo(datasource.entityAliasId).pipe(
@@ -200,14 +217,14 @@ export class AliasController implements IAliasController {
                   datasources.push(newDatasource);
                 }
                 return datasources;*/
-                return [newDatasource];
+                return newDatasource;
               } else {
                 if (aliasInfo.stateEntity) {
                   newDatasource = deepClone(datasource);
                   newDatasource.unresolvedStateEntity = true;
-                  return [newDatasource];
+                  return newDatasource;
                 } else {
-                  return [];
+                  return null;
                   // throw new Error('Unable to resolve datasource.');
                 }
               }
@@ -232,13 +249,13 @@ export class AliasController implements IAliasController {
                     entityType: entity.entityType
                   }
                 };
-                return [datasource];
+                return datasource;
               } else {
                 if (aliasInfo.stateEntity) {
                   datasource.unresolvedStateEntity = true;
-                  return [datasource];
+                  return datasource;
                 } else {
-                  return [];
+                  return null;
                   // throw new Error('Unable to resolve datasource.');
                 }
               }
@@ -248,10 +265,10 @@ export class AliasController implements IAliasController {
       } else {
         datasource.aliasName = datasource.entityName;
         datasource.name = datasource.entityName;
-        return of([datasource]);
+        return of(datasource);
       }
     } else {
-      return of([datasource]);
+      return of(datasource);
     }
   }
 
@@ -354,18 +371,14 @@ export class AliasController implements IAliasController {
     );
   }
 
-  resolveDatasources(datasources: Array<Datasource>): Observable<Array<Datasource>> {
-    const newDatasources = deepClone(datasources);
-    const observables = new Array<Observable<Array<Datasource>>>();
+  resolveDatasources(datasources: Array<Datasource>, singleEntity?: boolean): Observable<Array<Datasource>> {
+    const newDatasources = deepClone(singleEntity ? [datasources[0]] : datasources);
+    const observables = new Array<Observable<Datasource>>();
     newDatasources.forEach((datasource) => {
       observables.push(this.resolveDatasource(datasource));
     });
     return forkJoin(observables).pipe(
-      map((arrayOfDatasources) => {
-        const result = new Array<Datasource>();
-        arrayOfDatasources.forEach((datasourcesArray) => {
-          result.push(...datasourcesArray);
-        });
+      map((result) => {
         let functionIndex = 0;
         result.forEach((datasource) => {
           if (datasource.type === DatasourceType.function) {
@@ -386,6 +399,9 @@ export class AliasController implements IAliasController {
             datasource.name = 'Unresolved';
             datasource.entityName = 'Unresolved';
           } else if (datasource.type === DatasourceType.entity) {
+            if (singleEntity) {
+              datasource.pageLink = createDefaultEntityDataPageLink(1);
+            }
             if (!datasource.pageLink) {
               datasource.pageLink = deepClone(defaultEntityDataPageLink);
             }

@@ -35,19 +35,21 @@ import {
   TelemetrySubscriber
 } from '@shared/models/telemetry/telemetry.models';
 import { UtilsService } from '@core/services/utils.service';
-import { EntityDataListener } from '@core/api/entity-data.service';
+import { EntityDataListener, EntityDataLoadResult } from '@core/api/entity-data.service';
 import { deepClone, isDefinedAndNotNull, isObject, objectHashCode } from '@core/utils';
 import { PageData } from '@shared/models/page/page-data';
 import { DataAggregator } from '@core/api/data-aggregator';
 import { NULL_UUID } from '@shared/models/id/has-uuid';
 import { EntityType } from '@shared/models/entity-type.models';
 import Timeout = NodeJS.Timeout;
+import { Observable, of, ReplaySubject, Subject } from 'rxjs';
 
 export interface EntityDataSubscriptionOptions {
   datasourceType: DatasourceType;
   dataKeys: Array<SubscriptionDataKey>;
   type: widgetType;
   entityFilter?: EntityFilter;
+  isLatestDataSubscription?: boolean;
   pageLink?: EntityDataPageLink;
   keyFilters?: Array<KeyFilter>;
   subscriptionTimewindow?: SubscriptionTimewindow;
@@ -59,21 +61,19 @@ declare type DataUpdatedCb = (data: DataSetHolder, dataIndex: number, dataKeyInd
 
 export class EntityDataSubscription {
 
-  private listeners: Array<EntityDataListener> = [];
   private datasourceType: DatasourceType = this.entityDataSubscriptionOptions.datasourceType;
-
-  private history = this.entityDataSubscriptionOptions.subscriptionTimewindow &&
-    isObject(this.entityDataSubscriptionOptions.subscriptionTimewindow.fixedWindow);
-
-  private realtime = this.entityDataSubscriptionOptions.subscriptionTimewindow &&
-    isDefinedAndNotNull(this.entityDataSubscriptionOptions.subscriptionTimewindow.realtimeWindowMs);
+  private history: boolean;
+  private realtime: boolean;
 
   private subscriber: TelemetrySubscriber;
+  private dataCommand: EntityDataCmd;
+  private subsCommand: EntityDataCmd;
 
   private attrFields: Array<EntityKey>;
   private tsFields: Array<EntityKey>;
   private latestValues: Array<EntityKey>;
 
+  private entityDataResolveSubject: Subject<EntityDataLoadResult>;
   private pageData: PageData<EntityData>;
   private subsTw: SubscriptionTimewindow;
   private dataAggregators: Array<DataAggregator>;
@@ -87,7 +87,11 @@ export class EntityDataSubscription {
   private tickElapsed = 0;
   private timer: Timeout;
 
-  constructor(private entityDataSubscriptionOptions: EntityDataSubscriptionOptions,
+  private dataResolved = false;
+  private started = false;
+
+  constructor(public entityDataSubscriptionOptions: EntityDataSubscriptionOptions,
+              private listener: EntityDataListener,
               private telemetryService: TelemetryService,
               private utils: UtilsService) {
     this.initializeSubscription();
@@ -126,50 +130,6 @@ export class EntityDataSubscription {
       }
       dataKey.key = key;
     }
-    if (this.datasourceType === DatasourceType.function) {
-      this.frequency = 1000;
-      if (this.entityDataSubscriptionOptions.type === widgetType.timeseries) {
-        this.frequency = Math.min(this.entityDataSubscriptionOptions.subscriptionTimewindow.aggregation.interval, 5000);
-      }
-    }
-  }
-
-  public addListener(listener: EntityDataListener) {
-    this.listeners.push(listener);
-  }
-
-  public hasListeners(): boolean {
-    return this.listeners.length > 0;
-  }
-
-  public removeListener(listener: EntityDataListener) {
-    this.listeners.splice(this.listeners.indexOf(listener), 1);
-  }
-
-  public syncListener(listener: EntityDataListener) {
-    if (this.pageData) {
-      let key: string;
-      let dataKey: SubscriptionDataKey;
-      const data: Array<Array<DataSetHolder>> = [];
-      for (let dataIndex = 0; dataIndex < this.pageData.data.length; dataIndex++) {
-        data[dataIndex] = [];
-        for (key of Object.keys(this.dataKeys)) {
-          if (this.datasourceType === DatasourceType.entity || this.entityDataSubscriptionOptions.type === widgetType.timeseries) {
-            const dataKeysList = this.dataKeys[key] as Array<SubscriptionDataKey>;
-            for (let i = 0; i < dataKeysList.length; i++) {
-              dataKey = dataKeysList[i];
-              const datasourceKey = `${key}_${i}`;
-              data[dataIndex][dataKey.index] = this.datasourceData[dataIndex][datasourceKey];
-            }
-          } else {
-            dataKey = this.dataKeys[key] as SubscriptionDataKey;
-            data[dataIndex][dataKey.index] = this.datasourceData[dataIndex][key];
-          }
-        }
-      }
-      listener.dataLoaded(this.pageData, data, listener.configDatasourceIndex);
-    }
-    this.listeners.push(listener);
   }
 
   public unsubscribe() {
@@ -192,19 +152,30 @@ export class EntityDataSubscription {
     this.pageData = null;
   }
 
-  public start() {
-    this.subsTw = this.entityDataSubscriptionOptions.subscriptionTimewindow;
+  public subscribe(): Observable<EntityDataLoadResult> {
+    if (!this.entityDataSubscriptionOptions.isLatestDataSubscription) {
+      this.entityDataResolveSubject = new ReplaySubject(1);
+    } else {
+      this.started = true;
+      this.dataResolved = true;
+    }
     if (this.datasourceType === DatasourceType.entity) {
       const entityFields: Array<EntityKey> =
         this.entityDataSubscriptionOptions.dataKeys.filter(dataKey => dataKey.type === DataKeyType.entityField).map(
-        dataKey => ({ type: EntityKeyType.ENTITY_FIELD, key: dataKey.name })
-      );
+          dataKey => ({ type: EntityKeyType.ENTITY_FIELD, key: dataKey.name })
+        );
       if (!entityFields.find(key => key.key === 'name')) {
         entityFields.push({
           type: EntityKeyType.ENTITY_FIELD,
           key: 'name'
         });
       }
+      if (!entityFields.find(key => key.key === 'label')) {
+        entityFields.push({
+          type: EntityKeyType.ENTITY_FIELD,
+          key: 'label'
+        });
+      }
 
       this.attrFields = this.entityDataSubscriptionOptions.dataKeys.filter(dataKey => dataKey.type === DataKeyType.attribute).map(
         dataKey => ({ type: EntityKeyType.ATTRIBUTE, key: dataKey.name })
@@ -217,9 +188,9 @@ export class EntityDataSubscription {
       this.latestValues = this.attrFields.concat(this.tsFields);
 
       this.subscriber = new TelemetrySubscriber(this.telemetryService);
-      const command = new EntityDataCmd();
+      this.dataCommand = new EntityDataCmd();
 
-      command.query = {
+      this.dataCommand.query = {
         entityFilter: this.entityDataSubscriptionOptions.entityFilter,
         pageLink: this.entityDataSubscriptionOptions.pageLink,
         keyFilters: this.entityDataSubscriptionOptions.keyFilters,
@@ -227,72 +198,17 @@ export class EntityDataSubscription {
         latestValues: this.latestValues
       };
 
-      if (this.entityDataSubscriptionOptions.type === widgetType.timeseries) {
-        if (this.tsFields.length > 0) {
-          if (this.history) {
-            command.historyCmd = {
-              keys: this.tsFields.map(key => key.key),
-              startTs: this.subsTw.fixedWindow.startTimeMs,
-              endTs: this.subsTw.fixedWindow.endTimeMs,
-              interval: this.subsTw.aggregation.interval,
-              limit: this.subsTw.aggregation.limit,
-              agg: this.subsTw.aggregation.type
+      if (this.entityDataSubscriptionOptions.isLatestDataSubscription) {
+        if (this.entityDataSubscriptionOptions.type === widgetType.latest) {
+          if (this.latestValues.length > 0) {
+            this.dataCommand.latestCmd = {
+              keys: this.latestValues
             };
-            if (this.subsTw.aggregation.stateData) {
-              command.historyCmd.startTs -= YEAR;
-            }
-          } else {
-            command.tsCmd = {
-              keys: this.tsFields.map(key => key.key),
-              startTs: this.subsTw.startTs,
-              timeWindow: this.subsTw.aggregation.timeWindow,
-              interval: this.subsTw.aggregation.interval,
-              limit: this.subsTw.aggregation.limit,
-              agg: this.subsTw.aggregation.type
-            }
-            if (this.subsTw.aggregation.stateData) {
-              command.historyCmd = {
-                keys: this.tsFields.map(key => key.key),
-                startTs: this.subsTw.startTs - YEAR,
-                endTs: this.subsTw.startTs,
-                interval: this.subsTw.aggregation.interval,
-                limit: this.subsTw.aggregation.limit,
-                agg: this.subsTw.aggregation.type
-              };
-            }
-            this.subscriber.reconnect$.subscribe(() => {
-              let newSubsTw: SubscriptionTimewindow = null;
-              this.listeners.forEach((listener) => {
-                if (!newSubsTw) {
-                  newSubsTw = listener.updateRealtimeSubscription();
-                } else {
-                  listener.setRealtimeSubscription(newSubsTw);
-                }
-              });
-              this.subsTw = newSubsTw;
-              command.tsCmd.startTs = this.subsTw.startTs;
-              command.tsCmd.timeWindow = this.subsTw.aggregation.timeWindow;
-              command.tsCmd.interval = this.subsTw.aggregation.interval;
-              command.tsCmd.limit = this.subsTw.aggregation.limit;
-              command.tsCmd.agg = this.subsTw.aggregation.type;
-              if (this.subsTw.aggregation.stateData) {
-                command.historyCmd.startTs = this.subsTw.startTs - YEAR;
-                command.historyCmd.endTs = this.subsTw.startTs;
-                command.historyCmd.interval = this.subsTw.aggregation.interval;
-                command.historyCmd.limit = this.subsTw.aggregation.limit;
-                command.historyCmd.agg = this.subsTw.aggregation.type;
-              }
-            });
           }
         }
-      } else if (this.entityDataSubscriptionOptions.type === widgetType.latest) {
-        if (this.latestValues.length > 0) {
-          command.latestCmd = {
-            keys: this.latestValues.map(key => key.key)
-          };
-        }
       }
-      this.subscriber.subscriptionCommands.push(command);
+
+      this.subscriber.subscriptionCommands.push(this.dataCommand);
 
       this.subscriber.entityData$.subscribe(
         (entityDataUpdate) => {
@@ -304,6 +220,30 @@ export class EntityDataSubscription {
         }
       );
 
+      this.subscriber.reconnect$.subscribe(() => {
+        const newSubsTw: SubscriptionTimewindow = this.listener.updateRealtimeSubscription();
+        this.listener.setRealtimeSubscription(newSubsTw);
+        this.subsTw = newSubsTw;
+        if (this.started && !this.entityDataSubscriptionOptions.isLatestDataSubscription) {
+          this.subsCommand.tsCmd.startTs = this.subsTw.startTs;
+          this.subsCommand.tsCmd.timeWindow = this.subsTw.aggregation.timeWindow;
+          this.subsCommand.tsCmd.interval = this.subsTw.aggregation.interval;
+          this.subsCommand.tsCmd.limit = this.subsTw.aggregation.limit;
+          this.subsCommand.tsCmd.agg = this.subsTw.aggregation.type;
+          if (this.subsTw.aggregation.stateData) {
+            this.subsCommand.historyCmd.startTs = this.subsTw.startTs - YEAR;
+            this.subsCommand.historyCmd.endTs = this.subsTw.startTs;
+            this.subsCommand.historyCmd.interval = this.subsTw.aggregation.interval;
+            this.subsCommand.historyCmd.limit = this.subsTw.aggregation.limit;
+            this.subsCommand.historyCmd.agg = this.subsTw.aggregation.type;
+          }
+          this.subsCommand.query = this.dataCommand.query;
+          this.subscriber.subscriptionCommands = [this.subsCommand];
+        } else {
+          this.subscriber.subscriptionCommands = [this.dataCommand];
+        }
+      });
+
       this.subscriber.subscribe();
     } else if (this.datasourceType === DatasourceType.function) {
       const entityData: EntityData = {
@@ -325,29 +265,46 @@ export class EntityDataSubscription {
         totalPages: 1
       };
       this.onPageData(pageData);
-      this.tickScheduledTime = this.utils.currentPerfTime();
-      if (this.history) {
-        this.onTick(true);
-      } else {
-        this.timer = setTimeout(this.onTick.bind(this, true), 0);
+      if (this.entityDataSubscriptionOptions.isLatestDataSubscription) {
+        if (this.entityDataSubscriptionOptions.type === widgetType.latest) {
+          this.frequency = 1000;
+          this.timer = setTimeout(this.onTick.bind(this, true), 0);
+        }
       }
     }
+    if (this.entityDataSubscriptionOptions.isLatestDataSubscription) {
+      return of(null);
+    } else {
+      return this.entityDataResolveSubject.asObservable();
+    }
   }
 
-  private onPageData(pageData: PageData<EntityData>) {
+  public start() {
+    if (this.entityDataSubscriptionOptions.isLatestDataSubscription) {
+      return;
+    }
+    this.subsTw = this.entityDataSubscriptionOptions.subscriptionTimewindow;
+    this.history = this.entityDataSubscriptionOptions.subscriptionTimewindow &&
+      isObject(this.entityDataSubscriptionOptions.subscriptionTimewindow.fixedWindow);
+    this.realtime = this.entityDataSubscriptionOptions.subscriptionTimewindow &&
+      isDefinedAndNotNull(this.entityDataSubscriptionOptions.subscriptionTimewindow.realtimeWindowMs);
+
+    if (this.timer) {
+      clearTimeout(this.timer);
+      this.timer = null;
+    }
+
     if (this.dataAggregators) {
       this.dataAggregators.forEach((aggregator) => {
         aggregator.destroy();
       })
-      this.dataAggregators = null;
     }
-    this.datasourceData = [];
     this.dataAggregators = [];
-    this.entityIdToDataIndex = {};
-    let tsKeyNames;
+    this.resetData();
+
     if (this.entityDataSubscriptionOptions.type === widgetType.timeseries) {
+      let tsKeyNames = [];
       if (this.datasourceType === DatasourceType.function) {
-        tsKeyNames = [];
         for (const key of Object.keys(this.dataKeys)) {
           const dataKeysList = this.dataKeys[key] as Array<SubscriptionDataKey>;
           dataKeysList.forEach((subscriptionDataKey) => {
@@ -357,20 +314,85 @@ export class EntityDataSubscription {
       } else {
         tsKeyNames = this.tsFields ? this.tsFields.map(field => field.key) : [];
       }
-    }
-    for (let dataIndex = 0; dataIndex < pageData.data.length; dataIndex++) {
-      const entityData = pageData.data[dataIndex];
-      this.entityIdToDataIndex[entityData.entityId.id] = dataIndex;
-      this.datasourceData[dataIndex] = {};
-      if (this.entityDataSubscriptionOptions.type === widgetType.timeseries) {
+      for (let dataIndex = 0; dataIndex < this.pageData.data.length; dataIndex++) {
         if (this.datasourceType === DatasourceType.function) {
           this.dataAggregators[dataIndex] = this.createRealtimeDataAggregator(this.subsTw, tsKeyNames,
-            DataKeyType.function, dataIndex, this.notifyListeners.bind(this));
+            DataKeyType.function, dataIndex, this.notifyListener.bind(this));
         } else if (!this.history && tsKeyNames.length) {
           this.dataAggregators[dataIndex] = this.createRealtimeDataAggregator(this.subsTw, tsKeyNames,
-            DataKeyType.timeseries, dataIndex, this.notifyListeners.bind(this));
+            DataKeyType.timeseries, dataIndex, this.notifyListener.bind(this));
         }
       }
+    }
+    if (this.datasourceType === DatasourceType.entity) {
+      this.subsCommand = new EntityDataCmd();
+      this.subsCommand.cmdId = this.dataCommand.cmdId;
+      if (this.entityDataSubscriptionOptions.type === widgetType.timeseries) {
+        if (this.tsFields.length > 0) {
+          if (this.history) {
+            this.subsCommand.historyCmd = {
+              keys: this.tsFields.map(key => key.key),
+              startTs: this.subsTw.fixedWindow.startTimeMs,
+              endTs: this.subsTw.fixedWindow.endTimeMs,
+              interval: this.subsTw.aggregation.interval,
+              limit: this.subsTw.aggregation.limit,
+              agg: this.subsTw.aggregation.type
+            };
+            if (this.subsTw.aggregation.stateData) {
+              this.subsCommand.historyCmd.startTs -= YEAR;
+            }
+          } else {
+            this.subsCommand.tsCmd = {
+              keys: this.tsFields.map(key => key.key),
+              startTs: this.subsTw.startTs,
+              timeWindow: this.subsTw.aggregation.timeWindow,
+              interval: this.subsTw.aggregation.interval,
+              limit: this.subsTw.aggregation.limit,
+              agg: this.subsTw.aggregation.type
+            }
+            if (this.subsTw.aggregation.stateData) {
+              this.subsCommand.historyCmd = {
+                keys: this.tsFields.map(key => key.key),
+                startTs: this.subsTw.startTs - YEAR,
+                endTs: this.subsTw.startTs,
+                interval: this.subsTw.aggregation.interval,
+                limit: this.subsTw.aggregation.limit,
+                agg: this.subsTw.aggregation.type
+              };
+            }
+          }
+        }
+      } else if (this.entityDataSubscriptionOptions.type === widgetType.latest) {
+        if (this.latestValues.length > 0) {
+          this.subsCommand.latestCmd = {
+            keys: this.latestValues
+          };
+        }
+      }
+      this.subscriber.subscriptionCommands = [this.subsCommand];
+      this.subscriber.update();
+    } else if (this.datasourceType === DatasourceType.function) {
+      this.frequency = 1000;
+      if (this.entityDataSubscriptionOptions.type === widgetType.timeseries) {
+        this.frequency = Math.min(this.entityDataSubscriptionOptions.subscriptionTimewindow.aggregation.interval, 5000);
+      }
+      this.tickScheduledTime = this.utils.currentPerfTime();
+      if (this.history) {
+        this.onTick(true);
+      } else {
+        this.timer = setTimeout(this.onTick.bind(this, true), 0);
+      }
+    }
+    this.started = true;
+  }
+
+  private resetData() {
+    this.datasourceData = [];
+    this.entityIdToDataIndex = {};
+    for (let dataIndex = 0; dataIndex < this.pageData.data.length; dataIndex++) {
+      const entityData = this.pageData.data[dataIndex];
+      this.entityIdToDataIndex[entityData.entityId.id] = dataIndex;
+      this.datasourceData[dataIndex] = {};
       for (const key of Object.keys(this.dataKeys)) {
         const dataKey = this.dataKeys[key];
         if (this.datasourceType === DatasourceType.entity || this.entityDataSubscriptionOptions.type === widgetType.timeseries) {
@@ -388,7 +410,23 @@ export class EntityDataSubscription {
       }
     }
     this.datasourceOrigData = deepClone(this.datasourceData);
+    if (this.entityDataSubscriptionOptions.type === widgetType.timeseries) {
+      for (const key of Object.keys(this.dataKeys)) {
+        const dataKeyList = this.dataKeys[key] as Array<SubscriptionDataKey>;
+        dataKeyList.forEach((dataKey) => {
+          delete dataKey.lastUpdateTime;
+        });
+      }
+    } else if (this.entityDataSubscriptionOptions.type === widgetType.latest) {
+      for (const key of Object.keys(this.dataKeys)) {
+        delete (this.dataKeys[key] as SubscriptionDataKey).lastUpdateTime;
+      }
+    }
+  }
 
+  private onPageData(pageData: PageData<EntityData>) {
+    this.pageData = pageData;
+    this.resetData();
     const data: Array<Array<DataSetHolder>> = [];
     for (let dataIndex = 0; dataIndex < pageData.data.length; dataIndex++) {
       const entityData = pageData.data[dataIndex];
@@ -401,28 +439,33 @@ export class EntityDataSubscription {
         }
       );
     }
-
-    this.pageData = pageData;
-
-    this.listeners.forEach((listener) => {
-      listener.dataLoaded(pageData, data,
-        listener.configDatasourceIndex);
-    });
+    if (!this.dataResolved) {
+      this.dataResolved = true;
+      this.entityDataResolveSubject.next(
+        {
+          pageData,
+          data,
+          datasourceIndex: this.listener.configDatasourceIndex
+        }
+      );
+      this.entityDataResolveSubject.complete();
+    } else {
+      this.listener.dataLoaded(pageData, data,
+        this.listener.configDatasourceIndex);
+    }
   }
 
   private onDataUpdate(update: Array<EntityData>) {
     for (const entityData of update) {
       const dataIndex = this.entityIdToDataIndex[entityData.entityId.id];
-      this.processEntityData(entityData, dataIndex, true, this.notifyListeners.bind(this));
+      this.processEntityData(entityData, dataIndex, true, this.notifyListener.bind(this));
     }
   }
 
-  private notifyListeners(data: DataSetHolder, dataIndex: number, dataKeyIndex: number, detectChanges: boolean) {
-    this.listeners.forEach((listener) => {
-      listener.dataUpdated(data,
-        listener.configDatasourceIndex,
+  private notifyListener(data: DataSetHolder, dataIndex: number, dataKeyIndex: number, detectChanges: boolean) {
+    this.listener.dataUpdated(data,
+      this.listener.configDatasourceIndex,
         dataIndex, dataKeyIndex, detectChanges);
-    });
   }
 
   private processEntityData(entityData: EntityData, dataIndex: number, aggregate: boolean,
@@ -596,14 +639,10 @@ export class EntityDataSubscription {
     const value = dataKey.func(time, prevSeries[1]);
     const series: [number, any] = [time, value];
     this.datasourceData[0][dataKey.key].data = [series];
-    this.listeners.forEach(
-      (listener) => {
-        listener.dataUpdated(this.datasourceData[0][dataKey.key],
-          listener.configDatasourceIndex,
-          0,
-          dataKey.index, detectChanges);
-      }
-    );
+    this.listener.dataUpdated(this.datasourceData[0][dataKey.key],
+      this.listener.configDatasourceIndex,
+      0,
+      dataKey.index, detectChanges);
   }
 
   private onTick(detectChanges: boolean) {

@@ -24,17 +24,24 @@ import { UtilsService } from '@core/services/utils.service';
 import { SubscriptionDataKey } from '@core/api/datasource-subcription';
 import { deepClone, objectHashCode } from '@core/utils';
 import { EntityDataSubscription, EntityDataSubscriptionOptions } from '@core/api/entity-data-subscription';
+import { Observable, of } from 'rxjs';
 
 export interface EntityDataListener {
   subscriptionType: widgetType;
-  subscriptionTimewindow: SubscriptionTimewindow;
+  subscriptionTimewindow?: SubscriptionTimewindow;
   configDatasource: Datasource;
   configDatasourceIndex: number;
   dataLoaded: (pageData: PageData<EntityData>, data: Array<Array<DataSetHolder>>, datasourceIndex: number) => void;
   dataUpdated: (data: DataSetHolder, datasourceIndex: number, dataIndex: number, dataKeyIndex: number, detectChanges: boolean) => void;
-  updateRealtimeSubscription: () => SubscriptionTimewindow;
-  setRealtimeSubscription: (subscriptionTimewindow: SubscriptionTimewindow) => void;
-  entityDataSubscriptionKey?: number;
+  updateRealtimeSubscription?: () => SubscriptionTimewindow;
+  setRealtimeSubscription?: (subscriptionTimewindow: SubscriptionTimewindow) => void;
+  subscription?: EntityDataSubscription;
+}
+
+export interface EntityDataLoadResult {
+  pageData: PageData<EntityData>;
+  data: Array<Array<DataSetHolder>>;
+  datasourceIndex: number;
 }
 
 @Injectable({
@@ -42,16 +49,48 @@ export interface EntityDataListener {
 })
 export class EntityDataService {
 
-  private subscriptions: {[entityDataSubscriptionKey: string]: EntityDataSubscription} = {};
-
   constructor(private telemetryService: TelemetryWebsocketService,
               private utils: UtilsService) {}
 
-  public subscribeToEntityData(listener: EntityDataListener) {
+  public prepareSubscription(listener: EntityDataListener): Observable<EntityDataLoadResult> {
     const datasource = listener.configDatasource;
     if (datasource.type === DatasourceType.entity && (!datasource.entityFilter || !datasource.pageLink)) {
+      return of(null);
+    }
+    listener.subscription = this.createSubscription(listener,
+      datasource.pageLink, datasource.keyFilters,
+      false);
+    return listener.subscription.subscribe();
+  }
+
+  public startSubscription(listener: EntityDataListener) {
+    if (listener.subscriptionType === widgetType.timeseries) {
+      listener.subscription.entityDataSubscriptionOptions.subscriptionTimewindow = deepClone(listener.subscriptionTimewindow);
+    }
+    listener.subscription.start();
+  }
+
+  public subscribeForLatestData(listener: EntityDataListener,
+                                pageLink: EntityDataPageLink,
+                                keyFilters: KeyFilter[]) {
+    const datasource = listener.configDatasource;
+    if (datasource.type === DatasourceType.entity && (!datasource.entityFilter || !pageLink)) {
       return;
     }
+    listener.subscription = this.createSubscription(listener,
+      pageLink, keyFilters,  true);
+    listener.subscription.subscribe();
+  }
+
+  public stopSubscription(listener: EntityDataListener) {
+    listener.subscription.unsubscribe();
+  }
+
+  private createSubscription(listener: EntityDataListener,
+                             pageLink: EntityDataPageLink,
+                             keyFilters: KeyFilter[],
+                             isLatestDataSubscription: boolean): EntityDataSubscription {
+    const datasource = listener.configDatasource;
     const subscriptionDataKeys: Array<SubscriptionDataKey> = [];
     datasource.dataKeys.forEach((dataKey) => {
       const subscriptionDataKey: SubscriptionDataKey = {
@@ -62,47 +101,19 @@ export class EntityDataService {
       };
       subscriptionDataKeys.push(subscriptionDataKey);
     });
-
     const entityDataSubscriptionOptions: EntityDataSubscriptionOptions = {
       datasourceType: datasource.type,
       dataKeys: subscriptionDataKeys,
       type: listener.subscriptionType
     };
-
-    if (listener.subscriptionType === widgetType.timeseries) {
-      entityDataSubscriptionOptions.subscriptionTimewindow = deepClone(listener.subscriptionTimewindow);
-    }
     if (entityDataSubscriptionOptions.datasourceType === DatasourceType.entity) {
       entityDataSubscriptionOptions.entityFilter = datasource.entityFilter;
-      entityDataSubscriptionOptions.pageLink = datasource.pageLink;
-      entityDataSubscriptionOptions.keyFilters = datasource.keyFilters;
-    }
-    listener.entityDataSubscriptionKey = objectHashCode(entityDataSubscriptionOptions);
-    let subscription: EntityDataSubscription;
-    if (this.subscriptions[listener.entityDataSubscriptionKey]) {
-      subscription = this.subscriptions[listener.entityDataSubscriptionKey];
-      subscription.syncListener(listener);
-    } else {
-      subscription = new EntityDataSubscription(entityDataSubscriptionOptions,
-        this.telemetryService, this.utils);
-      this.subscriptions[listener.entityDataSubscriptionKey] = subscription;
-      subscription.addListener(listener);
-      subscription.start();
-    }
-  }
-
-  public unsubscribeFromDatasource(listener: EntityDataListener) {
-    if (listener.entityDataSubscriptionKey) {
-      const subscription = this.subscriptions[listener.entityDataSubscriptionKey];
-      if (subscription) {
-        subscription.removeListener(listener);
-        if (!subscription.hasListeners()) {
-          subscription.unsubscribe();
-          delete this.subscriptions[listener.entityDataSubscriptionKey];
-        }
-      }
-      listener.entityDataSubscriptionKey = null;
+      entityDataSubscriptionOptions.pageLink = pageLink;
+      entityDataSubscriptionOptions.keyFilters = keyFilters;
     }
+    entityDataSubscriptionOptions.isLatestDataSubscription = isLatestDataSubscription;
+    return new EntityDataSubscription(entityDataSubscriptionOptions,
+      listener, this.telemetryService, this.utils);
   }
 
 }

@@ -98,7 +98,8 @@ export interface IAliasController {
   getAliasInfo(aliasId: string): Observable<AliasInfo>;
   getEntityAliasId(aliasName: string): string;
   getInstantAliasInfo(aliasId: string): AliasInfo;
-  resolveDatasources(datasources: Array<Datasource>): Observable<Array<Datasource>>;
+  resolveSingleEntityInfo(aliasId: string): Observable<EntityInfo>;
+  resolveDatasources(datasources: Array<Datasource>, singleEntity?: boolean): Observable<Array<Datasource>>;
   resolveAlarmSource(alarmSource: Datasource): Observable<Datasource>;
   getEntityAliases(): EntityAliases;
   updateCurrentAliasEntity(aliasId: string, currentEntity: EntityInfo);
@@ -202,8 +203,8 @@ export interface WidgetSubscriptionOptions {
   alarmsMaxCountLoad?: number;
   alarmsFetchSize?: number;
   datasources?: Array<Datasource>;
-  keyFilters?: Array<KeyFilter>;
-  pageLink?: EntityDataPageLink;
+  hasDataPageLink?: boolean;
+  singleEntity?: boolean;
   targetDeviceAliasIds?: Array<string>;
   targetDeviceIds?: Array<string>;
   useDashboardTimewindow?: boolean;
@@ -264,7 +265,7 @@ export interface IWidgetSubscription {
 
   onAliasesChanged(aliasIds: Array<string>): boolean;
 
-  onDashboardTimewindowChanged(dashboardTimewindow: Timewindow): boolean;
+  onDashboardTimewindowChanged(dashboardTimewindow: Timewindow): void;
 
   updateDataVisibility(index: number): void;
 
@@ -278,6 +279,10 @@ export interface IWidgetSubscription {
 
   subscribe(): void;
 
+  subscribeForLatestData(datasourceIndex: number,
+                         pageLink: EntityDataPageLink,
+                         keyFilters: KeyFilter[]): void;
+
   isDataResolved(): boolean;
 
   destroy(): void;

@@ -22,7 +22,6 @@ import {
   WidgetSubscriptionOptions
 } from '@core/api/widget-api.models';
 import {
-  DataKey,
   DataSet,
   DataSetHolder,
   Datasource,
@@ -43,20 +42,18 @@ import {
   toHistoryTimewindow,
   WidgetTimewindow
 } from '@app/shared/models/time/time.models';
-import { Observable, ReplaySubject, Subject, throwError } from 'rxjs';
+import { forkJoin, Observable, of, ReplaySubject, Subject, throwError } from 'rxjs';
 import { CancelAnimationFrame } from '@core/services/raf.service';
 import { EntityType } from '@shared/models/entity-type.models';
 import { AlarmInfo, AlarmSearchStatus } from '@shared/models/alarm.models';
 import { createLabelFromDatasource, deepClone, isDefined, isEqual } from '@core/utils';
 import { AlarmSourceListener } from '@core/http/alarm.service';
-import { DatasourceListener } from '@core/api/datasource.service';
 import { EntityId } from '@app/shared/models/id/entity-id';
-import { DataKeyType } from '@shared/models/telemetry/telemetry.models';
-import { entityFields } from '@shared/models/entity.models';
 import * as moment_ from 'moment';
 import { PageData } from '@shared/models/page/page-data';
 import { EntityDataListener } from '@core/api/entity-data.service';
-import { EntityData, EntityDataPageLink, EntityKeyType } from '@shared/models/query/query.models';
+import { EntityData, EntityDataPageLink, EntityKeyType, KeyFilter } from '@shared/models/query/query.models';
+import { map } from 'rxjs/operators';
 
 const moment = moment_;
 
@@ -73,12 +70,14 @@ export class WidgetSubscription implements IWidgetSubscription {
   subscriptionTimewindow: SubscriptionTimewindow;
   useDashboardTimewindow: boolean;
 
+  hasDataPageLink: boolean;
+  singleEntity: boolean;
+
   datasourcePages: PageData<Datasource>[];
   dataPages: PageData<Array<DatasourceData>>[];
   entityDataListeners: Array<EntityDataListener>;
   configuredDatasources: Array<Datasource>;
 
-  initDataSubscriptionSubject: Subject<void>;
   data: Array<DatasourceData>;
   datasources: Array<Datasource>;
   // datasourceListeners: Array<DatasourceListener>;
@@ -211,6 +210,8 @@ export class WidgetSubscription implements IWidgetSubscription {
       // this.datasources = this.ctx.utils.validateDatasources(options.datasources);
       this.configuredDatasources = this.ctx.utils.validateDatasources(options.datasources);
       this.entityDataListeners = [];
+      this.hasDataPageLink = options.hasDataPageLink;
+      this.singleEntity = options.singleEntity;
       // this.datasourceListeners = [];
       this.datasourcePages = [];
       this.datasources = [];
@@ -271,11 +272,11 @@ export class WidgetSubscription implements IWidgetSubscription {
     const initRpcSubject = new ReplaySubject();
     if (this.targetDeviceAliasIds && this.targetDeviceAliasIds.length > 0) {
       this.targetDeviceAliasId = this.targetDeviceAliasIds[0];
-      this.ctx.aliasController.getAliasInfo(this.targetDeviceAliasId).subscribe(
-        (aliasInfo) => {
-          if (aliasInfo.currentEntity && aliasInfo.currentEntity.entityType === EntityType.DEVICE) {
-            this.targetDeviceId = aliasInfo.currentEntity.id;
-            this.targetDeviceName = aliasInfo.currentEntity.name;
+      this.ctx.aliasController.resolveSingleEntityInfo(this.targetDeviceAliasId).subscribe(
+        (entityInfo) => {
+          if (entityInfo && entityInfo.entityType === EntityType.DEVICE) {
+            this.targetDeviceId = entityInfo.id;
+            this.targetDeviceName = entityInfo.name;
             if (this.targetDeviceId) {
               this.rpcEnabled = true;
             } else {
@@ -348,34 +349,72 @@ export class WidgetSubscription implements IWidgetSubscription {
   }
 
   private initDataSubscription(): Observable<any> {
-    this.initDataSubscriptionSubject = new ReplaySubject(1);
+    const initDataSubscriptionSubject = new ReplaySubject(1);
     this.loadStDiff().subscribe(() => {
       if (!this.ctx.aliasController) {
         this.hasResolvedData = true;
-        // this.configureData();
-        // initDataSubscriptionSubject.next();
-        // initDataSubscriptionSubject.complete();
-        this.subscribe();
+        this.prepareDataSubscriptions().subscribe(
+          () => {
+            initDataSubscriptionSubject.next();
+            initDataSubscriptionSubject.complete();
+          }
+        );
       } else {
-        this.ctx.aliasController.resolveDatasources(this.configuredDatasources).subscribe(
+        this.ctx.aliasController.resolveDatasources(this.configuredDatasources, this.singleEntity).subscribe(
           (datasources) => {
             this.configuredDatasources = datasources;
-            /* if (datasources && datasources.length) {
-              this.hasResolvedData = true;
-            }*/
-            this.subscribe();
-            // this.configureData();
-            // initDataSubscriptionSubject.next();
-            // initDataSubscriptionSubject.complete();
+            this.prepareDataSubscriptions().subscribe(
+              () => {
+                initDataSubscriptionSubject.next();
+                initDataSubscriptionSubject.complete();
+              }
+            );
           },
           (err) => {
             this.notifyDataLoaded();
-            this.initDataSubscriptionSubject.error(err);
+            initDataSubscriptionSubject.error(err);
           }
         );
       }
     });
-    return this.initDataSubscriptionSubject.asObservable();
+    return initDataSubscriptionSubject.asObservable();
+  }
+
+  private prepareDataSubscriptions(): Observable<any> {
+    if (this.hasDataPageLink) {
+      this.hasResolvedData = true;
+      return of(null);
+    }
+    const resolveResultObservables = this.configuredDatasources.map((datasource, index) => {
+      const listener: EntityDataListener = {
+        subscriptionType: this.type,
+        configDatasource: datasource,
+        configDatasourceIndex: index,
+        dataLoaded: (pageData, data1, datasourceIndex) => {
+          this.dataLoaded(pageData, data1, datasourceIndex, true)
+        },
+        dataUpdated: this.dataUpdated.bind(this),
+        updateRealtimeSubscription: () => {
+          this.subscriptionTimewindow = this.updateRealtimeSubscription();
+          return this.subscriptionTimewindow;
+        },
+        setRealtimeSubscription: (subscriptionTimewindow) => {
+          this.updateRealtimeSubscription(deepClone(subscriptionTimewindow));
+        }
+      };
+      this.entityDataListeners.push(listener);
+      return this.ctx.entityDataService.prepareSubscription(listener);
+    });
+    return forkJoin(resolveResultObservables).pipe(
+      map((resolveResults) => {
+        resolveResults.forEach((resolveResult) => {
+          this.dataLoaded(resolveResult.pageData, resolveResult.data, resolveResult.datasourceIndex, false);
+        });
+        this.configureLoadedData();
+        this.hasResolvedData = true;
+        this.notifyDataLoaded();
+      })
+    );
   }
 
 /*  private initDataSubscriptionOld(): Observable<any> {
@@ -592,13 +631,12 @@ export class WidgetSubscription implements IWidgetSubscription {
     });
   }
 
-  onDashboardTimewindowChanged(newDashboardTimewindow: Timewindow): boolean {
+  onDashboardTimewindowChanged(newDashboardTimewindow: Timewindow) {
     if (this.type === widgetType.timeseries || this.type === widgetType.alarm) {
       if (this.useDashboardTimewindow) {
         if (!isEqual(this.timeWindowConfig, newDashboardTimewindow) && newDashboardTimewindow) {
-          // this.timeWindowConfig = deepClone(newDashboardTimewindow);
-          // this.update();
-          // TODO:
+          this.timeWindowConfig = deepClone(newDashboardTimewindow);
+          this.update();
           return true;
         }
       }
@@ -785,8 +823,12 @@ export class WidgetSubscription implements IWidgetSubscription {
   }
 
   update() {
-    this.unsubscribe();
-    this.subscribe();
+    if (this.type === widgetType.rpc || this.type === widgetType.alarm) {
+      this.unsubscribe();
+      this.subscribe();
+    } else {
+      this.dataSubscribe();
+    }
   }
 
   subscribe(): void {
@@ -802,6 +844,29 @@ export class WidgetSubscription implements IWidgetSubscription {
     }
   }
 
+  subscribeForLatestData(datasourceIndex: number,
+                         pageLink: EntityDataPageLink,
+                         keyFilters: KeyFilter[]): void {
+    let entityDataListener = this.entityDataListeners[datasourceIndex];
+    if (entityDataListener) {
+      this.ctx.entityDataService.stopSubscription(entityDataListener);
+    }
+    const datasource = this.configuredDatasources[datasourceIndex];
+    if (datasource) {
+      entityDataListener = {
+        subscriptionType: this.type,
+        configDatasource: datasource,
+        configDatasourceIndex: datasourceIndex,
+        dataLoaded: (pageData, data1, datasourceIndex1) => {
+          this.dataLoaded(pageData, data1, datasourceIndex1, true)
+        },
+        dataUpdated: this.dataUpdated.bind(this)
+      };
+      this.entityDataListeners[datasourceIndex] = entityDataListener;
+      this.ctx.entityDataService.subscribeForLatestData(entityDataListener, pageLink, keyFilters);
+    }
+  }
+
   private doSubscribe() {
     if (this.type === widgetType.rpc) {
       return;
@@ -809,6 +874,12 @@ export class WidgetSubscription implements IWidgetSubscription {
     if (this.type === widgetType.alarm) {
       this.alarmsSubscribe();
     } else {
+      this.dataSubscribe();
+    }
+  }
+
+  private dataSubscribe() {
+    if (!this.hasDataPageLink) {
       this.notifyDataLoading();
       if (this.type === widgetType.timeseries && this.timeWindowConfig) {
         this.updateRealtimeSubscription();
@@ -819,62 +890,10 @@ export class WidgetSubscription implements IWidgetSubscription {
           this.onDataUpdated();
         }
       }
-      // let index = 0;
       const forceUpdate = !this.datasources.length;
-      this.configuredDatasources.forEach((datasource, index) => {
-        const listener: EntityDataListener = {
-          subscriptionType: this.type,
-          subscriptionTimewindow: this.subscriptionTimewindow,
-          configDatasource: datasource,
-          configDatasourceIndex: index,
-          dataLoaded: this.dataLoaded.bind(this),
-          dataUpdated: this.dataUpdated.bind(this),
-          updateRealtimeSubscription: () => {
-            this.subscriptionTimewindow = this.updateRealtimeSubscription();
-            return this.subscriptionTimewindow;
-          },
-          setRealtimeSubscription: (subscriptionTimewindow) => {
-            this.updateRealtimeSubscription(deepClone(subscriptionTimewindow));
-          }
-        };
-
-        /*if (this.comparisonEnabled && datasource.isAdditional) {
-          listener.subscriptionTimewindow = this.timewindowForComparison;
-          listener.updateRealtimeSubscription = () => {
-            this.subscriptionTimewindow = this.updateSubscriptionForComparison();
-            return this.subscriptionTimewindow;
-          };
-          listener.setRealtimeSubscription = () => {
-            this.updateSubscriptionForComparison();
-          };
-        }*/
-
-/*        let entityFieldKey = false;
-
-        for (let a = 0; a < datasource.dataKeys.length; a++) {
-          if (datasource.dataKeys[a].type !== DataKeyType.entityField) {
-            this.data[index + a].data = [];
-          } else {
-            entityFieldKey = true;
-          }
-        }
-        index += datasource.dataKeys.length;*/
-
-        this.entityDataListeners.push(listener);
-        // this.datasourceListeners.push(listener);
-
-        // if (datasource.dataKeys.length) {
-        //  this.ctx.datasourceService.subscribeToDatasource(listener);
-        // }
-
-        this.ctx.entityDataService.subscribeToEntityData(listener);
-
-       /* if (datasource.unresolvedStateEntity || entityFieldKey ||
-          !datasource.dataKeys.length ||
-          (datasource.type === DatasourceType.entity && !datasource.entityId)
-        ) {
-          forceUpdate = true;
-        }*/
+      this.entityDataListeners.forEach((listener) => {
+        listener.subscriptionTimewindow = this.subscriptionTimewindow;
+        this.ctx.entityDataService.startSubscription(listener);
       });
       if (forceUpdate) {
         this.notifyDataLoaded();
@@ -1000,7 +1019,9 @@ export class WidgetSubscription implements IWidgetSubscription {
         this.alarmsUnsubscribe();
       } else {
         this.entityDataListeners.forEach((listener) => {
-          this.ctx.entityDataService.unsubscribeFromDatasource(listener);
+          if (listener != null) {
+            this.ctx.entityDataService.stopSubscription(listener);
+          }
         });
         this.entityDataListeners.length = 0;
         this.resetData();
@@ -1129,7 +1150,9 @@ export class WidgetSubscription implements IWidgetSubscription {
     return this.timewindowForComparison;
   }
 
-  private dataLoaded(pageData: PageData<EntityData>, data: Array<Array<DataSetHolder>>, datasourceIndex: number) {
+  private dataLoaded(pageData: PageData<EntityData>,
+                     data: Array<Array<DataSetHolder>>,
+                     datasourceIndex: number, isUpdate: boolean) {
     const datasource = this.configuredDatasources[datasourceIndex];
     datasource.dataReceived = true;
     const datasources = pageData.data.map((entityData, index) =>
@@ -1152,14 +1175,8 @@ export class WidgetSubscription implements IWidgetSubscription {
       totalPages: pageData.totalPages
     };
     this.dataPages[datasourceIndex] = datasourceDataPage;
-    this.configureLoadedData();
-    const readyCount = this.configuredDatasources.filter(d => d.dataReceived).length;
-    if (this.configuredDatasources.length === readyCount) {
-      this.hasResolvedData = true;
-      this.initDataSubscriptionSubject.next();
-      this.initDataSubscriptionSubject.complete();
+    if (isUpdate) {
       this.configureLoadedData();
-      this.notifyDataLoaded();
       this.onDataUpdated(true);
     }
   }
@@ -1238,6 +1255,9 @@ export class WidgetSubscription implements IWidgetSubscription {
         dataKey,
         data: []
       };
+      if (data && data[keyIndex] && data[keyIndex].data) {
+        datasourceData.data = data[keyIndex].data;
+      }
       return datasourceData;
     });
   }
@@ -1275,6 +1295,7 @@ export class WidgetSubscription implements IWidgetSubscription {
     const startIndex = configuredDatasource.dataKeyStartIndex;
     const dataKeysCount = configuredDatasource.dataKeys.length;
     const index = startIndex + dataIndex*dataKeysCount + dataKeyIndex;
+    this.notifyDataLoaded();
     let update = true;
     let currentData: DataSetHolder;
     if (this.displayLegend && this.legendData.keys[index].dataKey.hidden) {

@@ -54,9 +54,15 @@ import {
 import { EntityRelationService } from '@core/http/entity-relation.service';
 import { deepClone, isDefined, isDefinedAndNotNull } from '@core/utils';
 import { Asset, AssetSearchQuery } from '@shared/models/asset.models';
-import { Device, DeviceCredentialsType, DeviceSearchQuery } from '@shared/models/device.models';
+import { ClaimResult, Device, DeviceCredentialsType, DeviceSearchQuery } from '@shared/models/device.models';
 import { EntityViewSearchQuery } from '@shared/models/entity-view.models';
 import { AttributeService } from '@core/http/attribute.service';
+import {
+  createDefaultEntityDataPageLink,
+  EntityData,
+  EntityDataQuery,
+  EntityFilter, EntityKeyType
+} from '@shared/models/query/query.models';
 
 @Injectable({
   providedIn: 'root'
@@ -360,6 +366,54 @@ export class EntityService {
     }
   }
 
+  public findEntityDataByQuery(query: EntityDataQuery, config?: RequestConfig): Observable<PageData<EntityData>> {
+    return this.http.post<PageData<EntityData>>('/api/entitiesQuery/find', query, defaultHttpOptionsFromConfig(config));
+  }
+
+  private entityDataToEntityInfo(entityData: EntityData): EntityInfo {
+    const entityInfo: EntityInfo = {
+      id: entityData.entityId.id,
+      entityType: entityData.entityId.entityType as EntityType
+    };
+    if (entityData.latest && entityData.latest[EntityKeyType.ENTITY_FIELD]) {
+      const fields = entityData.latest[EntityKeyType.ENTITY_FIELD];
+      if (fields.name) {
+        entityInfo.name = fields.name.value;
+      }
+      if (fields.label) {
+        entityInfo.label = fields.label.value;
+      }
+    }
+    return entityInfo;
+  }
+
+  public findSingleEntityInfoByEntityFilter(filter: EntityFilter, config?: RequestConfig): Observable<EntityInfo> {
+    const query: EntityDataQuery = {
+      entityFilter: filter,
+      pageLink: createDefaultEntityDataPageLink(1),
+      entityFields: [
+        {
+          type: EntityKeyType.ENTITY_FIELD,
+          key: 'name'
+        },
+        {
+          type: EntityKeyType.ENTITY_FIELD,
+          key: 'label'
+        }
+      ]
+    };
+    return this.findEntityDataByQuery(query, config).pipe(
+      map((data) => {
+        if (data.data.length) {
+          const entityData = data.data[0];
+          return this.entityDataToEntityInfo(entityData);
+        } else {
+          return null;
+        }
+      })
+    );
+  }
+
   public getAliasFilterTypesByEntityTypes(entityTypes: Array<EntityType | AliasEntityType>): Array<AliasFilterType> {
     const allAliasFilterTypes: Array<AliasFilterType> = Object.keys(AliasFilterType).map((key) => AliasFilterType[key]);
     if (!entityTypes || !entityTypes.length) {
@@ -605,7 +659,7 @@ export class EntityService {
   public resolveAlias(entityAlias: EntityAlias, stateParams: StateParams): Observable<AliasInfo> {
     const filter = entityAlias.filter;
     return this.resolveAliasFilter(filter, stateParams).pipe(
-      map((result) => {
+      mergeMap((result) => {
         const aliasInfo: AliasInfo = {
           alias: entityAlias.alias,
           entityFilter: result.entityFilter,
@@ -615,30 +669,19 @@ export class EntityService {
         };
         aliasInfo.resolvedEntities = result.entities;
         aliasInfo.currentEntity = null;
-        if (aliasInfo.resolvedEntities.length) {
-          aliasInfo.currentEntity = aliasInfo.resolvedEntities[0];
+        if (!aliasInfo.resolveMultiple && aliasInfo.entityFilter) {
+          return this.findSingleEntityInfoByEntityFilter(aliasInfo.entityFilter,
+            {ignoreLoading: true, ignoreErrors: true}).pipe(
+            map((entity) => {
+              aliasInfo.currentEntity = entity;
+              return aliasInfo;
+            })
+          );
         }
-        return aliasInfo;
+        return of(aliasInfo);
       })
     );
   }
-/*
-  public resolveEntityFilter(filter: EntityAliasFilter, stateParams: StateParams): EntityFilter {
-    const stateEntityInfo = this.getStateEntityInfo(filter, stateParams);
-    let result: EntityFilter = filter;
-    const stateEntityId = stateEntityInfo.entityId;
-    if (filter.type === AliasFilterType.stateEntity) {
-      result = {
-        singleEntity: stateEntityId,
-        type: AliasFilterType.singleEntity
-      };
-    } else if (filter.rootStateEntity) {
-      let rootEntityType;
-      let rootEntityId;
-
-    }
-    return result;
-  }*/
 
   public resolveAliasFilter(filter: EntityAliasFilter, stateParams: StateParams): Observable<EntityAliasFilterResult> {
     const result: EntityAliasFilterResult = {

@@ -114,6 +114,17 @@ export class TelemetryWebsocketService implements TelemetryService {
     this.publishCommands();
   }
 
+  public update(subscriber: TelemetrySubscriber) {
+    subscriber.subscriptionCommands.forEach(
+      (subscriptionCommand) => {
+        if (subscriptionCommand.cmdId && subscriptionCommand instanceof EntityDataCmd) {
+          this.cmdsWrapper.entityDataCmds.push(subscriptionCommand);
+        }
+      }
+    );
+    this.publishCommands();
+  }
+
   public unsubscribe(subscriber: TelemetrySubscriber) {
     if (this.isActive) {
       subscriber.subscriptionCommands.forEach(

@@ -39,7 +39,7 @@
     </mat-toolbar>
     <div fxFlex class="table-container">
       <table mat-table [dataSource]="entityDatasource"
-                 matSort [matSortActive]="sortOrderProperty" [matSortDirection]="pageLink.sortDirection()" matSortDisableClear>
+                 matSort [matSortActive]="sortOrderProperty" [matSortDirection]="pageLinkSortDirection()" matSortDisableClear>
         <ng-container [matColumnDef]="column.def" *ngFor="let column of columns; trackBy: trackByColumnDef;">
           <mat-header-cell [ngStyle]="headerStyle(column)" *matHeaderCellDef mat-sort-header> {{ column.title }} </mat-header-cell>
           <mat-cell *matCellDef="let entity;"

@@ -32,26 +32,23 @@ import {
   DataKey,
   Datasource,
   DatasourceData,
-  DatasourceType,
   WidgetActionDescriptor,
   WidgetConfig
 } from '@shared/models/widget.models';
 import { IWidgetSubscription } from '@core/api/widget-api.models';
 import { UtilsService } from '@core/services/utils.service';
 import { TranslateService } from '@ngx-translate/core';
-import { deepClone, isDefined, isNumber, createLabelFromDatasource, hashCode } from '@core/utils';
+import { createLabelFromDatasource, deepClone, hashCode, isDefined, isNumber } from '@core/utils';
 import cssjs from '@core/css/css';
-import { PageLink } from '@shared/models/page/page-link';
-import { Direction, SortOrder, sortOrderFromString } from '@shared/models/page/sort-order';
 import { CollectionViewer, DataSource } from '@angular/cdk/collections';
 import { DataKeyType } from '@shared/models/telemetry/telemetry.models';
 import { BehaviorSubject, fromEvent, merge, Observable, of } from 'rxjs';
 import { emptyPageData, PageData } from '@shared/models/page/page-data';
 import { EntityId } from '@shared/models/id/entity-id';
 import { entityTypeTranslations } from '@shared/models/entity-type.models';
-import { catchError, debounceTime, distinctUntilChanged, map, tap } from 'rxjs/operators';
+import { debounceTime, distinctUntilChanged, map, tap } from 'rxjs/operators';
 import { MatPaginator } from '@angular/material/paginator';
-import { MatSort } from '@angular/material/sort';
+import { MatSort, SortDirection } from '@angular/material/sort';
 import { DomSanitizer, SafeHtml } from '@angular/platform-browser';
 import {
   CellContentInfo,
@@ -59,15 +56,13 @@ import {
   constructTableCssString,
   DisplayColumn,
   EntityColumn,
-  EntityData,
-  fromEntityColumnDef,
+  EntityData, entityDataSortOrderFromString, findColumnByEntityKey, findEntityKeyByColumnDef,
   getCellContentInfo,
   getCellStyleInfo,
   getColumnWidth,
   getEntityValue,
   TableWidgetDataKeySettings,
   TableWidgetSettings,
-  toEntityColumnDef,
   widthStyle
 } from '@home/components/widget/lib/table-widget.models';
 import { ConnectedPosition, Overlay, OverlayConfig, OverlayRef } from '@angular/cdk/overlay';
@@ -77,6 +72,13 @@ import {
   DisplayColumnsPanelComponent,
   DisplayColumnsPanelData
 } from '@home/components/widget/lib/display-columns-panel.component';
+import {
+  Direction,
+  EntityDataPageLink,
+  entityDataPageLinkSortDirection,
+  EntityKeyType,
+  KeyFilter
+} from '@shared/models/query/query.models';
 
 interface EntitiesTableWidgetSettings extends TableWidgetSettings {
   entitiesTitle: string;
@@ -103,7 +105,7 @@ export class EntitiesTableWidgetComponent extends PageComponent implements OnIni
 
   public displayPagination = true;
   public pageSizeOptions;
-  public pageLink: PageLink;
+  public pageLink: EntityDataPageLink;
   public sortOrderProperty: string;
   public textSearchMode = false;
   public columns: Array<EntityColumn> = [];
@@ -150,8 +152,13 @@ export class EntitiesTableWidgetComponent extends PageComponent implements OnIni
               private domSanitizer: DomSanitizer) {
     super(store);
 
-    const sortOrder: SortOrder = sortOrderFromString(this.defaultSortOrder);
-    this.pageLink = new PageLink(this.defaultPageSize, 0, null, sortOrder);
+    // const sortOrder: EntityDataSortOrder = sortOrderFromString(this.defaultSortOrder);
+    this.pageLink = {
+      page: 0,
+      pageSize: this.defaultPageSize,
+      textSearch: null
+    };
+      // new PageLink(this.defaultPageSize, 0, null, sortOrder);
   }
 
   ngOnInit(): void {
@@ -191,11 +198,15 @@ export class EntitiesTableWidgetComponent extends PageComponent implements OnIni
 
   public onDataUpdated() {
     this.ngZone.run(() => {
-      this.entityDatasource.updateEntitiesData(this.subscription.data);
+      this.entityDatasource.dataUpdated(); // .updateEntitiesData(this.subscription.data);
       this.ctx.detectChanges();
     });
   }
 
+  public pageLinkSortDirection(): SortDirection {
+    return entityDataPageLinkSortDirection(this.pageLink);
+  }
+
   private initializeConfig() {
     this.ctx.widgetActions = [this.searchAction, this.columnDisplayAction];
 
@@ -256,7 +267,11 @@ export class EntitiesTableWidgetComponent extends PageComponent implements OnIni
           name: 'entityName',
           label: 'entityName',
           def: 'entityName',
-          title: entityNameColumnTitle
+          title: entityNameColumnTitle,
+          entityKey: {
+            key: 'name',
+            type: EntityKeyType.ENTITY_FIELD
+          }
         } as EntityColumn
       );
       this.contentsInfo.entityName = {
@@ -273,7 +288,11 @@ export class EntitiesTableWidgetComponent extends PageComponent implements OnIni
           name: 'entityLabel',
           label: 'entityLabel',
           def: 'entityLabel',
-          title: entityLabelColumnTitle
+          title: entityLabelColumnTitle,
+          entityKey: {
+            key: 'label',
+            type: EntityKeyType.ENTITY_FIELD
+          }
         } as EntityColumn
       );
       this.contentsInfo.entityLabel = {
@@ -291,6 +310,10 @@ export class EntitiesTableWidgetComponent extends PageComponent implements OnIni
           label: 'entityType',
           def: 'entityType',
           title: this.translate.instant('entity.entity-type'),
+          entityKey: {
+            key: 'entityType',
+            type: EntityKeyType.ENTITY_FIELD
+          }
         } as EntityColumn
       );
       this.contentsInfo.entityType = {
@@ -309,8 +332,19 @@ export class EntitiesTableWidgetComponent extends PageComponent implements OnIni
     if (datasource) {
       datasource.dataKeys.forEach((entityDataKey) => {
         const dataKey: EntityColumn = deepClone(entityDataKey) as EntityColumn;
+        dataKey.entityKey = {
+          key: dataKey.name,
+          type: null
+        };
         if (dataKey.type === DataKeyType.function) {
           dataKey.name = dataKey.label;
+          dataKey.entityKey.type = EntityKeyType.ENTITY_FIELD;
+        } else if (dataKey.type === DataKeyType.entityField) {
+          dataKey.entityKey.type = EntityKeyType.ENTITY_FIELD;
+        } else if (dataKey.type === DataKeyType.attribute) {
+          dataKey.entityKey.type = EntityKeyType.ATTRIBUTE;
+        } else if (dataKey.type === DataKeyType.timeseries) {
+          dataKey.entityKey.type = EntityKeyType.TIME_SERIES;
         }
         dataKeys.push(dataKey);
 
@@ -331,14 +365,19 @@ export class EntitiesTableWidgetComponent extends PageComponent implements OnIni
     if (this.settings.defaultSortOrder && this.settings.defaultSortOrder.length) {
       this.defaultSortOrder = this.settings.defaultSortOrder;
     }
-    this.pageLink.sortOrder = sortOrderFromString(this.defaultSortOrder);
-    this.sortOrderProperty = toEntityColumnDef(this.pageLink.sortOrder.property, this.columns);
+
+    this.pageLink.sortOrder = entityDataSortOrderFromString(this.defaultSortOrder, this.columns);
+    let sortColumn: EntityColumn;
+    if (this.pageLink.sortOrder) {
+      sortColumn = findColumnByEntityKey(this.pageLink.sortOrder.key, this.columns);
+    }
+    this.sortOrderProperty = sortColumn ? sortColumn.def : null;
 
     if (this.actionCellDescriptors.length) {
       this.displayedColumns.push('actions');
     }
     this.entityDatasource = new EntityDatasource(
-      this.translate, dataKeys, this.subscription.datasources);
+      this.translate, dataKeys, this.subscription);
   }
 
   private editColumnsToDisplay($event: Event) {
@@ -416,9 +455,12 @@ export class EntitiesTableWidgetComponent extends PageComponent implements OnIni
     } else {
       this.pageLink.page = 0;
     }
-    this.pageLink.sortOrder.property = fromEntityColumnDef(this.sort.active, this.columns);
-    this.pageLink.sortOrder.direction = Direction[this.sort.direction.toUpperCase()];
-    this.entityDatasource.loadEntities(this.pageLink);
+    this.pageLink.sortOrder = {
+      key: findEntityKeyByColumnDef(this.sort.active, this.columns),
+      direction: Direction[this.sort.direction.toUpperCase()]
+    };
+    const keyFilters: KeyFilter[] = null; // TODO:
+    this.entityDatasource.loadEntities(this.pageLink, keyFilters);
     this.ctx.detectChanges();
   }
 
@@ -523,18 +565,19 @@ class EntityDatasource implements DataSource<EntityData> {
   private entitiesSubject = new BehaviorSubject<EntityData[]>([]);
   private pageDataSubject = new BehaviorSubject<PageData<EntityData>>(emptyPageData<EntityData>());
 
-  private allEntities: Array<EntityData> = [];
-  private allEntitiesSubject = new BehaviorSubject<EntityData[]>([]);
-  private allEntities$: Observable<Array<EntityData>> = this.allEntitiesSubject.asObservable();
+//  private allEntities: Array<EntityData> = [];
+//  private allEntitiesSubject = new BehaviorSubject<EntityData[]>([]);
+//  private allEntities$: Observable<Array<EntityData>> = this.allEntitiesSubject.asObservable();
 
   private currentEntity: EntityData = null;
 
   constructor(
        private translate: TranslateService,
        private dataKeys: Array<DataKey>,
-       datasources: Array<Datasource>
+       private subscription: IWidgetSubscription
+       // datasources: Array<Datasource>
     ) {
-
+/*
     for (const datasource of datasources) {
       if (datasource.type === DatasourceType.entity && !datasource.entityId) {
         continue;
@@ -558,7 +601,7 @@ class EntityDatasource implements DataSource<EntityData> {
       });
       this.allEntities.push(entity);
     }
-    this.allEntitiesSubject.next(this.allEntities);
+    this.allEntitiesSubject.next(this.allEntities);*/
   }
 
   connect(collectionViewer: CollectionViewer): Observable<EntityData[] | ReadonlyArray<EntityData>> {
@@ -570,18 +613,63 @@ class EntityDatasource implements DataSource<EntityData> {
     this.pageDataSubject.complete();
   }
 
-  loadEntities(pageLink: PageLink) {
-    this.fetchEntities(pageLink).pipe(
+  loadEntities(pageLink: EntityDataPageLink, keyFilters: KeyFilter[]) {
+    this.subscription.subscribeForLatestData(0, pageLink, keyFilters);
+/*    this.fetchEntities(pageLink).pipe(
       catchError(() => of(emptyPageData<EntityData>())),
     ).subscribe(
       (pageData) => {
         this.entitiesSubject.next(pageData.data);
         this.pageDataSubject.next(pageData);
       }
-    );
+    );*/
   }
 
-  updateEntitiesData(data: DatasourceData[]) {
+  dataUpdated() {
+    const datasourcesPageData = this.subscription.datasourcePages[0];
+    const dataPageData = this.subscription.dataPages[0];
+    const entities = new Array<EntityData>();
+    datasourcesPageData.data.forEach((datasource, index) => {
+      entities.push(this.datasourceToEntityData(datasource, dataPageData.data[index]));
+    });
+    const entitiesPageData: PageData<EntityData> = {
+      data: entities,
+      totalPages: datasourcesPageData.totalPages,
+      totalElements: datasourcesPageData.totalElements,
+      hasNext: datasourcesPageData.hasNext
+    };
+    this.entitiesSubject.next(entities);
+    this.pageDataSubject.next(entitiesPageData);
+  }
+
+  private datasourceToEntityData(datasource: Datasource, data: DatasourceData[]): EntityData {
+    const entity: EntityData = {
+      id: {} as EntityId,
+      entityName: datasource.entityName,
+      entityLabel: datasource.entityLabel ? datasource.entityLabel : datasource.entityName
+    };
+    if (datasource.entityId) {
+      entity.id.id = datasource.entityId;
+    }
+    if (datasource.entityType) {
+      entity.id.entityType = datasource.entityType;
+      entity.entityType = this.translate.instant(entityTypeTranslations.get(datasource.entityType).type);
+    } else {
+      entity.entityType = '';
+    }
+    this.dataKeys.forEach((dataKey, index) => {
+      const keyData = data[index].data;
+      if (keyData && keyData.length && keyData[0].length > 1) {
+        const value = keyData[0][1];
+        entity[dataKey.label] = value;
+      } else {
+        entity[dataKey.label] = '';
+      }
+    });
+    return entity;
+  }
+
+/*  updateEntitiesData(data: DatasourceData[]) {
     for (let i = 0; i < this.allEntities.length; i++) {
       const entity = this.allEntities[i];
       for (let a = 0; a < this.dataKeys.length; a++) {
@@ -597,7 +685,7 @@ class EntityDatasource implements DataSource<EntityData> {
       }
     }
     this.allEntitiesSubject.next(this.allEntities);
-  }
+  }*/
 
   isEmpty(): Observable<boolean> {
     return this.entitiesSubject.pipe(
@@ -625,9 +713,9 @@ class EntityDatasource implements DataSource<EntityData> {
       (this.currentEntity.id.id === entity.id.id);
   }
 
-  private fetchEntities(pageLink: PageLink): Observable<PageData<EntityData>> {
+ /* private fetchEntities(pageLink: PageLink): Observable<PageData<EntityData>> {
     return this.allEntities$.pipe(
       map((data) => pageLink.filterData(data))
     );
-  }
+  }*/
 }

@@ -19,6 +19,7 @@ import { DataKey, WidgetConfig } from '@shared/models/widget.models';
 import { getDescendantProp, isDefined } from '@core/utils';
 import { alarmFields, AlarmInfo } from '@shared/models/alarm.models';
 import * as tinycolor_ from 'tinycolor2';
+import { Direction, EntityDataSortOrder, EntityKey } from '@shared/models/query/query.models';
 
 const tinycolor = tinycolor_;
 
@@ -49,6 +50,7 @@ export interface EntityData {
 export interface EntityColumn extends DataKey {
   def: string;
   title: string;
+  entityKey?: EntityKey;
 }
 
 export interface DisplayColumn {
@@ -73,6 +75,58 @@ export interface CellStyleInfo {
   cellStyleFunction?: CellStyleFunction;
 }
 
+
+export function entityDataSortOrderFromString(strSortOrder: string, columns: EntityColumn[]): EntityDataSortOrder {
+  if (!strSortOrder && !strSortOrder.length) {
+    return null;
+  }
+  let property: string;
+  let direction = Direction.ASC;
+  if (strSortOrder.startsWith('-')) {
+    direction = Direction.DESC;
+    property = strSortOrder.substring(1);
+  } else {
+    if (strSortOrder.startsWith('+')) {
+      property = strSortOrder.substring(1);
+    } else {
+      property = strSortOrder;
+    }
+  }
+  if (!property && !property.length) {
+    return null;
+  }
+  const column = findColumnByLabel(property, columns);
+  if (column && column.entityKey) {
+    return {key: column.entityKey, direction};
+  }
+  return null;
+}
+
+export function findColumnByEntityKey(key: EntityKey, columns: EntityColumn[]): EntityColumn {
+  if (key) {
+    return columns.find(theColumn => theColumn.entityKey &&
+      theColumn.entityKey.type === key.type && theColumn.entityKey.key === key.key);
+  } else {
+    return null;
+  }
+}
+
+export function findEntityKeyByColumnDef(def: string, columns: EntityColumn[]): EntityKey {
+  return findColumnByDef(def, columns).entityKey;
+}
+
+export function findColumn(searchProperty: string, searchValue: string, columns: EntityColumn[]): EntityColumn {
+  return columns.find(theColumn => theColumn[searchProperty] === searchValue);
+}
+
+export function findColumnByLabel(label: string, columns: EntityColumn[]): EntityColumn {
+  return findColumn('label', label, columns);
+}
+
+export function findColumnByDef(def: string, columns: EntityColumn[]): EntityColumn {
+  return findColumn('def', def, columns);
+}
+
 export function findColumnProperty(searchProperty: string, searchValue: string, columnProperty: string, columns: EntityColumn[]): string {
   let res = searchValue;
   const column = columns.find(theColumn => theColumn[searchProperty] === searchValue);
@@ -82,6 +136,10 @@ export function findColumnProperty(searchProperty: string, searchValue: string,
   return res;
 }
 
+export function toEntityKey(def: string, columns: EntityColumn[]): string {
+  return findColumnProperty('def', def, 'label', columns);
+}
+
 export function toEntityColumnDef(label: string, columns: EntityColumn[]): string {
   return findColumnProperty('label', label, 'def', columns);
 }

@@ -346,12 +346,19 @@ export class WidgetComponentService {
       } else {
         result.typeParameters.useCustomDatasources = false;
       }
+      if (isUndefined(result.typeParameters.hasDataPageLink)) {
+        result.typeParameters.hasDataPageLink = false;
+      }
       if (isUndefined(result.typeParameters.maxDatasources)) {
         result.typeParameters.maxDatasources = -1;
       }
       if (isUndefined(result.typeParameters.maxDataKeys)) {
         result.typeParameters.maxDataKeys = -1;
       }
+      if (isUndefined(result.typeParameters.singleEntity)) {
+        result.typeParameters.singleEntity = result.typeParameters.maxDatasources === 1 &&
+          result.typeParameters.maxDataKeys === 1;
+      }
       if (isUndefined(result.typeParameters.dataKeysOptional)) {
         result.typeParameters.dataKeysOptional = false;
       }

@@ -620,14 +620,9 @@ export class WidgetComponent extends PageComponent implements OnInit, AfterViewI
 
     this.rxSubscriptions.push(this.widgetContext.dashboard.dashboardTimewindowChanged.subscribe(
       (dashboardTimewindow) => {
-        // TODO:
-        let subscriptionChanged = false;
         for (const id of Object.keys(this.widgetContext.subscriptions)) {
           const subscription = this.widgetContext.subscriptions[id];
-          subscriptionChanged = subscriptionChanged || subscription.onDashboardTimewindowChanged(dashboardTimewindow);
-        }
-        if (subscriptionChanged && !this.typeParameters.useCustomDatasources) {
-          this.reInit();
+          subscription.onDashboardTimewindowChanged(dashboardTimewindow);
         }
       }
     ));
@@ -845,6 +840,8 @@ export class WidgetComponent extends PageComponent implements OnInit, AfterViewI
       options = {
         type: this.widget.type,
         stateData: this.typeParameters.stateData,
+        hasDataPageLink: this.typeParameters.hasDataPageLink,
+        singleEntity: this.typeParameters.singleEntity,
         comparisonEnabled: comparisonSettings.comparisonEnabled,
         timeForComparison: comparisonSettings.timeForComparison
       };

@@ -16,6 +16,7 @@
 
 import { AliasFilterType, EntityFilters } from '@shared/models/alias.models';
 import { EntityId } from '@shared/models/id/entity-id';
+import { SortDirection } from '@angular/material/sort';
 
 export enum EntityKeyType {
   ATTRIBUTE = 'ATTRIBUTE',
@@ -122,18 +123,30 @@ export interface EntityDataPageLink {
   sortOrder?: EntityDataSortOrder;
 }
 
-export const defaultEntityDataPageLink: EntityDataPageLink = {
-  pageSize: 1024,
-  page: 0,
-  sortOrder: {
-    key: {
-      type: EntityKeyType.ENTITY_FIELD,
-      key: 'createdTime'
-    },
-    direction: Direction.DESC
+export function entityDataPageLinkSortDirection(pageLink: EntityDataPageLink): SortDirection {
+  if (pageLink.sortOrder) {
+    return (pageLink.sortOrder.direction + '').toLowerCase() as SortDirection;
+  } else {
+    return '' as SortDirection;
   }
 }
 
+export function createDefaultEntityDataPageLink(pageSize: number): EntityDataPageLink {
+  return {
+    pageSize,
+    page: 0,
+    sortOrder: {
+      key: {
+        type: EntityKeyType.ENTITY_FIELD,
+        key: 'createdTime'
+      },
+      direction: Direction.DESC
+    }
+  }
+}
+
+export const defaultEntityDataPageLink: EntityDataPageLink = createDefaultEntityDataPageLink(1024);
+
 export interface EntityCountQuery {
   entityFilter: EntityFilter;
 }

@@ -21,7 +21,7 @@ import { Observable, ReplaySubject, Subject } from 'rxjs';
 import { EntityId } from '@shared/models/id/entity-id';
 import { map } from 'rxjs/operators';
 import { NgZone } from '@angular/core';
-import { EntityData, EntityDataQuery } from '@shared/models/query/query.models';
+import { EntityData, EntityDataQuery, EntityKey } from '@shared/models/query/query.models';
 import { PageData } from '@shared/models/page/page-data';
 
 export enum DataKeyType {
@@ -139,7 +139,7 @@ export interface EntityHistoryCmd {
 }
 
 export interface LatestValueCmd {
-  keys: Array<string>;
+  keys: Array<EntityKey>;
 }
 
 export interface TimeSeriesCmd {
@@ -153,7 +153,7 @@ export interface TimeSeriesCmd {
 
 export class EntityDataCmd implements WebsocketCmd {
   cmdId: number;
-  query: EntityDataQuery;
+  query?: EntityDataQuery;
   historyCmd?: EntityHistoryCmd;
   latestCmd?: LatestValueCmd;
   tsCmd?: TimeSeriesCmd;
@@ -314,6 +314,7 @@ export class EntityDataUpdate implements EntityDataUpdateMsg {
 
 export interface TelemetryService {
   subscribe(subscriber: TelemetrySubscriber);
+  update(subscriber: TelemetrySubscriber);
   unsubscribe(subscriber: TelemetrySubscriber);
 }
 
@@ -360,6 +361,10 @@ export class TelemetrySubscriber {
     this.telemetryService.subscribe(this);
   }
 
+  public update() {
+    this.telemetryService.update(this);
+  }
+
   public unsubscribe() {
     this.telemetryService.unsubscribe(this);
     this.complete();

@@ -150,6 +150,8 @@ export interface WidgetTypeParameters {
   maxDataKeys?: number;
   dataKeysOptional?: boolean;
   stateData?: boolean;
+  hasDataPageLink?: boolean;
+  singleEntity?: boolean;
 }
 
 export interface WidgetControllerDescriptor {