Drag/Drop from Tilegrid to Tilegrid with different datasource gives JS-error

[Sytematic]

Hello,

I am using (SC_SNAPSHOT-2011-03-15/PowerEdition Deployment 2011-03-15), with FireFox 3.6.16.

I want to do the following, as described in the code below. Two tile grids, one with a Datasource "Pattern", and one with DataSource "Flavour_hasPatterns_Pattern", which look like below:

Pattern.ds.xml

<?xml version="1.0" encoding="UTF-8"?>
<DataSource ID="Pattern" serverType="sql" tableName="Pattern" requiresAuthentication="true"> 
  <fields> 
    <field name="Pattern_id" type="sequence" primaryKey="true"/>  
    <field name="patternName" title="patternName" type="text" required="false" length="128"> 
      <validators></validators> 
    </field>  
    <field name="fileName" title="fileName" type="image" required="false"> 
      <validators></validators> 
    </field>  
  </fields>  
  <operationBindings> 
    <operationBinding operationType="add" requiresAuthentication="true" requiresRole="CAN_CREATE_PATTERN"> 
    </operationBinding>  
    <operationBinding operationType="fetch" requiresAuthentication="true" requiresRole="CAN_READ_PATTERN"> 
    </operationBinding>  
    <operationBinding operationType="update" requiresAuthentication="true" requiresRole="CAN_UPDATE_PATTERN"> 
    </operationBinding>  
    <operationBinding operationType="remove" requiresAuthentication="true" requiresRole="CAN_DELETE_PATTERN"> 
    </operationBinding> 
  </operationBindings> 
</DataSource>

Flavour_hasPatterns_Pattern.ds.xml

<?xml version="1.0" encoding="UTF-8"?>
<DataSource ID="Flavour_hasPatterns_Pattern" serverType="sql" tableName="Flavour_hasPatterns_Pattern" requiresRole="ROLE_USER" requiresAuthentication="true"> 
  <fields> 
    <field name="hasPatterns_id" type="sequence" primaryKey="true"/>  
    <field name="Flavour_id" type="integer" foreignKey="Flavour.Flavour_id"/>  
    <field name="Pattern_id" type="integer" foreignKey="Pattern.Pattern_id"/>  
    <field name="patternName" type="text" tableName="Pattern" customSQL="true"/> 
    <field name="fileName" type="image" tableName="Pattern" customSQL="true"/>
  </fields>  
  <operationBindings> 
    <operationBinding operationType="fetch" customValueFields="patternName" customCriteriaFields="patternName"> 
      <tableClause>Flavour_hasPatterns_Pattern, Pattern</tableClause>  
      <whereClause>Flavour_hasPatterns_Pattern.Pattern_id = Pattern.Pattern_id AND ($defaultWhereClause)</whereClause> 
    </operationBinding> 
  </operationBindings> 
</DataSource>

I want to drag from a tilegrid with DataSource Pattern to the tile grid with DataSource Flavour_hasPatterns_Pattern. Since there is a foreign key between the two, I assume this is possible (yet i'm not sure, is it?)

My widget that does this looks as follows:

public class PatternEditorWidget extends VLayout {
	
	private Record record;
	
	private DataSource patternDs = DataSource.get("Pattern");
	private DataSource flavourToPatternDs = DataSource.get("Flavour_hasPatterns_Pattern");
	private PatternTileGrid tiles = new PatternTileGrid();
	private TargetTileGrid target = new TargetTileGrid();
	private static final int TILE_HEIGHT = 150;
	private static final int TILE_WIDTH  = 100;
	
	public PatternEditorWidget(Record rec){
		this.record=rec;
		init();
		addMember(tiles);
		addMember(target);
	}
	
	public void init(){
		setWidth100();
		setHeight100();
		setOverflow(Overflow.SCROLL);
	}
	
	protected class PatternTileGrid extends TileGrid{
		public PatternTileGrid(){
			setWidth100();
		    setTileWidth(TILE_WIDTH);
		    setTileHeight(TILE_HEIGHT);

		    setOverflow(Overflow.SCROLL);
			setShowAllRecords(true);
			setDataSource(patternDs);
		    setAutoFetchData(true);
		    DetailViewerField pictureField = new DetailViewerField("fileName");
		    pictureField.setImageURLPrefix("../uploads/Pattern/");  
		    pictureField.setImageWidth(87);  
		    pictureField.setImageHeight(133);  
		    setCanDrag(true); 
		    setCanDrop(true);
		    setCanDragReposition(true);
		    setDragDataAction(DragDataAction.COPY);
		    setFields( pictureField, new DetailViewerField("patternName"));
		}

	
	}
	
	/**
	 * Window where patterns can be dragged in, and dragged out. In goes via COPY, out goes via CUT. 
	 * This way, the user can easily select two patterns it wants to use.
	 *
	 */
	protected class TargetTileGrid extends TileGrid {
		public TargetTileGrid(){
			setWidth100();
			setDataSource(flavourToPatternDs);
			setCanAcceptDrop(true);
			setCanDrag(true);
			setCanDrop(true);
			setCanDragReposition(true);
		    DetailViewerField pictureField = new DetailViewerField("fileName");
 
		    pictureField.setImageWidth(TILE_WIDTH);  
		    pictureField.setImageHeight(TILE_HEIGHT); 
			setFields(pictureField, new DetailViewerField("patternName"));
		}

	}
}

When I drop something from the source to the target, the following error is thrown:

14:22:31.743 [ERROR] [generatedcode] 14:22:31.742:MUP4:WARN:Log:TypeError: this.data is undefined
    TileGrid.drop(event=>{Obj}, eventInfo=>undef) @ generatedcode/sc/modules/ISC_Grids.js:3439
    Canvas.handleDrop(_1=>{Obj},  _2=>undef) @ generatedcode/sc/modules/ISC_Core.js:3128
    [c]EventHandler.bubbleEvent(_1=>{Obj},  _2=>"drop",  _3=>undef) @ generatedcode/sc/modules/ISC_Core.js:1571
    [c]EventHandler.handleEvent(_1=>{Obj},  _2=>"drop") @ generatedcode/sc/modules/ISC_Core.js:1300
    [c]EventHandler.handleDragStop() @ generatedcode/sc/modules/ISC_Core.js:1505
    EventHandler._handleMouseUp([object MouseEvent], undef) @ generatedcode/sc/modules/ISC_Core.js:1401
    [c]EventHandler.handleMouseUp(_1=>[object MouseEvent]) @ generatedcode/sc/modules/ISC_Core.js:1397
    [c]EventHandler.dispatch(_1=>isc_c_EventHandler_handleMouseUp,  _2=>[object MouseEvent]) @ generatedcode/sc/modules/ISC_Core.js:1634
    anonymous([object MouseEvent]) @ generatedcode/sc/modules/ISC_Core.js:61
    unnamed() @ 


com.smartgwt.client.core.JsObject$SGWT_WARN: 14:22:31.742:MUP4:WARN:Log:TypeError: this.data is undefined
    TileGrid.drop(event=>{Obj}, eventInfo=>undef) @ generatedcode/sc/modules/ISC_Grids.js:3439
    Canvas.handleDrop(_1=>{Obj},  _2=>undef) @ generatedcode/sc/modules/ISC_Core.js:3128
    [c]EventHandler.bubbleEvent(_1=>{Obj},  _2=>"drop",  _3=>undef) @ generatedcode/sc/modules/ISC_Core.js:1571
    [c]EventHandler.handleEvent(_1=>{Obj},  _2=>"drop") @ generatedcode/sc/modules/ISC_Core.js:1300
    [c]EventHandler.handleDragStop() @ generatedcode/sc/modules/ISC_Core.js:1505
    EventHandler._handleMouseUp([object MouseEvent], undef) @ generatedcode/sc/modules/ISC_Core.js:1401
    [c]EventHandler.handleMouseUp(_1=>[object MouseEvent]) @ generatedcode/sc/modules/ISC_Core.js:1397
    [c]EventHandler.dispatch(_1=>isc_c_EventHandler_handleMouseUp,  _2=>[object MouseEvent]) @ generatedcode/sc/modules/ISC_Core.js:1634
    anonymous([object MouseEvent]) @ generatedcode/sc/modules/ISC_Core.js:61
    unnamed() @ 

    at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:39)
    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27)
    at java.lang.reflect.Constructor.newInstance(Constructor.java:513)
    at com.google.gwt.dev.shell.MethodAdaptor.invoke(MethodAdaptor.java:105)
    at com.google.gwt.dev.shell.MethodDispatch.invoke(MethodDispatch.java:71)
    at com.google.gwt.dev.shell.OophmSessionHandler.invoke(OophmSessionHandler.java:157)
    at com.google.gwt.dev.shell.BrowserChannelServer.reactToMessages(BrowserChannelServer.java:281)
    at com.google.gwt.dev.shell.BrowserChannelServer.processConnection(BrowserChannelServer.java:531)
    at com.google.gwt.dev.shell.BrowserChannelServer.run(BrowserChannelServer.java:352)
    at java.lang.Thread.run(Thread.java:680)

The question is: am I doing something wrong, or am I too ambitious? Any pointer to a solution would be greatly appreciated!

[Isomorphic]

This should be fine - the error you're getting suggests that the TileGrid does not have a dataset. You set autoFetchData - did you see a request for data, and did it succeed and return valid data?

[Sytematic]

Actually no, this is what the console says when I do the drag/drop:

Uncaught JavaScript exception [this.data is undefined] in http://127.0.0.1:8888/generatedcode/sc/modules/ISC_Grids.js, line 3439

So I don't see the typical DSRequest being made...

[Isomorphic]

The question is about the dsRequest when the TileGrid is first created and does its initial fetch (via autoFetchData).

[Sytematic]

Aha, i know what causes this. The target grid didn't have setAutoFetchData(true). Adding this solved the error.

EDIT
Sorry, a second too late. Thanks for pointing this out.