Lwm2m: front add validator json for security config value

@@ -88,6 +88,9 @@
       <mat-error *ngIf="deviceCredentialsFormGroup.get('credentialsValue').hasError('required')">
         {{ 'device.lwm2m-value-required' | translate }}
       </mat-error>
+      <mat-error *ngIf="deviceCredentialsFormGroup.get('credentialsValue').hasError('jsonError')">
+        {{ 'device.lwm2m-value-json-error' | translate }}
+      </mat-error>
       <div mat-dialog-actions fxLayoutAlign="center center">
         <button mat-raised-button color="primary"
                 matTooltip="{{'device.lwm2m-value-edit-tip' | translate }}"

@@ -196,13 +196,19 @@ export class DeviceCredentialsComponent implements ControlValueAccessor, OnInit,
         this.deviceCredentialsFormGroup.get('credentialsBasic').disable({emitEvent: false});
         break;
       case DeviceCredentialsType.X509_CERTIFICATE:
-      case DeviceCredentialsType.LWM2M_CREDENTIALS:
         this.deviceCredentialsFormGroup.get('credentialsValue').setValidators([Validators.required]);
         this.deviceCredentialsFormGroup.get('credentialsValue').updateValueAndValidity({emitEvent: false});
         this.deviceCredentialsFormGroup.get('credentialsId').setValidators([]);
         this.deviceCredentialsFormGroup.get('credentialsId').updateValueAndValidity({emitEvent: false});
         this.deviceCredentialsFormGroup.get('credentialsBasic').disable({emitEvent: false});
         break;
+      case DeviceCredentialsType.LWM2M_CREDENTIALS:
+        this.deviceCredentialsFormGroup.get('credentialsValue').setValidators([Validators.required, this.jsonValidator]);
+        this.deviceCredentialsFormGroup.get('credentialsValue').updateValueAndValidity({emitEvent: false});
+        this.deviceCredentialsFormGroup.get('credentialsId').setValidators([]);
+        this.deviceCredentialsFormGroup.get('credentialsId').updateValueAndValidity({emitEvent: false});
+        this.deviceCredentialsFormGroup.get('credentialsBasic').disable({emitEvent: false});
+        break;
       case DeviceCredentialsType.MQTT_BASIC:
         this.deviceCredentialsFormGroup.get('credentialsBasic').enable({emitEvent: false});
         this.deviceCredentialsFormGroup.get('credentialsBasic').updateValueAndValidity({emitEvent: false});
@@ -247,7 +253,11 @@ export class DeviceCredentialsComponent implements ControlValueAccessor, OnInit,
     if (credentialsValue === null || credentialsValue.length === 0) {
       credentialsValue = getDefaultSecurityConfig();
     } else {
-      credentialsValue = JSON.parse(credentialsValue);
+      try {
+        credentialsValue = JSON.parse(credentialsValue);
+      } catch (e) {
+        credentialsValue = getDefaultSecurityConfig();
+      }
     }
     const credentialsId = this.deviceCredentialsFormGroup.get('credentialsId').value || DEFAULT_END_POINT;
     this.dialog.open<SecurityConfigComponent, DeviceCredentialsDialogLwm2mData, object>(SecurityConfigComponent, {
@@ -273,4 +283,18 @@ export class DeviceCredentialsComponent implements ControlValueAccessor, OnInit,
   private isDefautLw2mResponse(response: object): boolean {
     return Object.keys(response).length === 0 || JSON.stringify(response) === '[{}]';
   }
+
+  private jsonValidator(control: FormControl) {
+    try {
+      debugger;
+      JSON.parse(control.value);
+      return null
+    } catch (e) {
+      return {
+        jsonError: {
+          parsedJson: "error"
+        }
+      }
+    }
+  }
 }

@@ -881,6 +881,7 @@
         "lwm2m-key-required": "LwM2M Security config key is required.",
         "lwm2m-value": "LwM2M Security config",
         "lwm2m-value-required": "LwM2M Security config value is required.",
+        "lwm2m-value-json-error": "LwM2M Security config value is not json format.",
         "lwm2m-endpoint": "Client endpoint/identity",
         "lwm2m-security-info": "Security Config Info",
         "lwm2m-value-edit": "Edit Security config",