title: Nativescript RadDataForm : JS: Binding: Binding error while setting property source of RadDataForm<myDataForm>
body: <p>I am trying to use the nativescript RadformData but when I bind the data model I am always got this error <strong>"JS: Binding: Binding error while setting property source of RadDataForm"</strong> when I navigate to the Radformdata page, I tried a lot of things by changing the dataform version in the package.json also I clean the platform but no luck , please advice </p>
  
  <p>this is my code :
  <strong>event-page.xml</strong></p>
  
  <pre><code>&lt;Page loaded="onPageLoaded" xmlns:df="nativescript-ui-dataform" 
  xmlns="http://www.nativescript.org/tns.xsd"&gt;
      &lt;ActionBar title="Add Event" /&gt;
          &lt;df:RadDataForm id="myDataForm" source="{{ calEvent }}"&gt;
              &lt;df:RadDataForm.properties&gt;
              &lt;df:EntityProperty name="title" hintText="Title" index="0"&gt;
                  &lt;df:EntityProperty.editor&gt;
                      &lt;df:PropertyEditor type="Text"&gt;&lt;/df:PropertyEditor&gt;
                  &lt;/df:EntityProperty.editor&gt;
              &lt;/df:EntityProperty&gt;
              &lt;df:EntityProperty name="description" hintText="Description" index="1"&gt;
                  &lt;df:EntityProperty.editor&gt;
                      &lt;df:PropertyEditor type="Text"&gt;&lt;/df:PropertyEditor&gt;
                  &lt;/df:EntityProperty.editor&gt;
              &lt;/df:EntityProperty&gt;
  
              &lt;df:EntityProperty name="stringDate" hintText="select date" index="2"&gt;
                  &lt;df:EntityProperty.editor&gt;
                      &lt;df:PropertyEditor type="DatePicker"&gt;&lt;/df:PropertyEditor&gt;
                  &lt;/df:EntityProperty.editor&gt;
              &lt;/df:EntityProperty&gt;
              &lt;df:EntityProperty name="dateDate" hintText="select date" index="3"&gt;
                  &lt;df:EntityProperty.editor&gt;
                      &lt;df:PropertyEditor type="DatePicker"&gt;&lt;/df:PropertyEditor&gt;
                  &lt;/df:EntityProperty.editor&gt;
              &lt;/df:EntityProperty&gt;
              &lt;df:EntityProperty name="timestampDate" hintText="select date" index="4" converter="{{ timestampConverter }}"&gt;
                  &lt;df:EntityProperty.editor&gt;
                      &lt;df:PropertyEditor type="DatePicker"&gt;&lt;/df:PropertyEditor&gt;
                  &lt;/df:EntityProperty.editor&gt;
              &lt;/df:EntityProperty&gt;
              &lt;df:EntityProperty name="stringTime" hintText="select time" index="5"&gt;
                  &lt;df:EntityProperty.editor&gt;
                      &lt;df:PropertyEditor type="TimePicker"&gt;&lt;/df:PropertyEditor&gt;
                  &lt;/df:EntityProperty.editor&gt;
              &lt;/df:EntityProperty&gt;
              &lt;df:EntityProperty name="dateTime" hintText="select time" index="6"&gt;
                  &lt;df:EntityProperty.editor&gt;
                      &lt;df:PropertyEditor type="TimePicker"&gt;&lt;/df:PropertyEditor&gt;
                  &lt;/df:EntityProperty.editor&gt;
              &lt;/df:EntityProperty&gt;
              &lt;df:EntityProperty name="timestampTime" hintText="select time" index="7" converter="{{ timestampConverter }}"&gt;
                  &lt;df:EntityProperty.editor&gt;
                      &lt;df:PropertyEditor type="TimePicker"&gt;&lt;/df:PropertyEditor&gt;
                  &lt;/df:EntityProperty.editor&gt;
              &lt;/df:EntityProperty&gt;
          &lt;/df:RadDataForm.properties&gt;
          &lt;/df:RadDataForm&gt;
  &lt;/Page&gt;
  </code></pre>
  
  <p>event-page.ts</p>
  
  <pre><code>import { EventViewModel } from "./event-view-model";
  import { Page } from "tns-core-modules/ui/page/page";
  
  export function onPageLoaded(args) {
      const page = &lt;Page&gt;args.object;
      var eventModel = new EventViewModel();
      page.bindingContext = eventModel;
  }
  </code></pre>
  
  <p>event-view-model.ts</p>
  
  <pre><code>import { Observable } from "tns-core-modules/data/observable";
  import { PropertyConverter } from "nativescript-ui-dataform";
  
  export class EventViewModel extends Observable {
  
      private _event: CalEvent;
  
      constructor() {
          super();
          this.set("timestampConverter", new TimestampConverter());
          this.onSetDefaults();
      }
  
      public onSetDefaults() {
          const stringDate = "1999-08-11";
          const dateDate = new Date();
          const timestampDate = (new Date()).getTime();   
          const stringTime = "11:04";
          const dateTime = new Date(1);
          const timestampTime = (new Date()).getTime();
          this._event =  new CalEvent("First Event","Desc",stringDate, dateDate, timestampDate, stringTime, dateTime, timestampTime);
      }
  
      get calEvent(): CalEvent{
          return this._event;
      }
  }
  
  export class TimestampConverter implements PropertyConverter {
  
      public convertFrom(timestamp: number) {
          const date = timestamp ? new Date(timestamp) : null;
          const result = date === null ? null : date.toJSON();
          return result;
      }
  
      public convertTo(dateString: string) {
          const date = new Date(dateString);
          const result = date ? date.getTime() : 0;
          return result;
      }
  }
  
  export class CalEvent {
      public title: string;
      public description: string;
      public stringDate: string;
      public dateDate: Date;
      public timestampDate: number;
      public stringTime: string;
      public dateTime: Date;
      public timestampTime: number;
  
  
      constructor(title: string, desc: string, stringDate: string, dateDate: Date, timestampDate: number, stringTime: string, dateTime: Date, timestampTime: number) {
          this.title = title;
          this.description = desc;
          this.stringDate = stringDate;
          this.dateDate = dateDate;
          this.timestampDate = timestampDate;
          this.stringTime = stringTime;
          this.dateTime = dateTime;
          this.timestampTime = timestampTime;
      }
  }
  
  </code></pre>