Bug: unable to remove record from ListGrid which has validation errors

[SiccoNaets]

I've found a bug with the removeData() and removeSelectedData() methods on ListGrid.

I have a ListGrid with a single field (emailField) and a RegExpValidator on that field (basically to ensure that people are entering valid email addresses).
I've also implemented my own Delete button on each row so that I can fire an event when a record is removed; per Svjard's instructions in this thread: http://forums.smartclient.com/showthread.php?t=12594

However, I've found that when a record fails the RegExpValidator (for instance, by entering "foo" as an email address), the RecordClickEvent does not contain a record (i.e. RecordClickEvent.getRecord() returns null - presumably because this is not a valid record.)

As a result, it becomes impossible to call ListGrid.removeData since you don't have a valid record to remove. ListGrid.removeSelectedData throws "com.google.gwt.core.client.JavaScriptException: (String): Invoking an instance method on a null instance" - I suspect because it simply tries to grab the currently selected record and of course that is null as well.

RecordClickEvent.getRecordNum() DOES return a valid index number; but since there is no ListGrid.removeData(int rowNum) method that is no help.

Source code:

public class EmailListGrid extends ListGrid {
	
	
	protected ListGridField emailField;
	protected ListGridField removeField;
	
	protected Vector<ListGridContentChangedHandler> contentChangeHandlers;
	
	private static final String EMAIL_REG_EXP = "^([a-zA-Z0-9_.\\-+])+@(([a-zA-Z0-9\\-])+\\.)+[a-zA-Z0-9]{2,4}$";
	private static final String DEFAULT_VALIDATION_MESSAGE = "Not a valid email address.";

	private static final String DEFAULT_SELECTION_EMPTY_MESSAGE = "No Emails";
	private static final boolean DEFAULT_SELECTION_CAN_REORDER_MESSAGES = false;
	private static final boolean DEFAULT_CAN_DRAG_RECORDS = false;
	private static final int DEFAULT_SELECTION_WIDTH=450;
	private static final int DEFAULT_SELECTION_HEIGHT=150;

	
	public EmailListGrid(String emailFieldName, String emailFieldLabel)
	{
		this(emailFieldName,emailFieldLabel,false);
	}
	
	public EmailListGrid(String emailFieldName, String emailFieldLabel,boolean canRemoveRecords)
	{
		super();
		contentChangeHandlers = new Vector<ListGridContentChangedHandler>();
		this.setShowHeader(false);
		this.setWidth(DEFAULT_SELECTION_WIDTH);
		this.setHeight(DEFAULT_SELECTION_HEIGHT);
		this.setEmptyMessage(DEFAULT_SELECTION_EMPTY_MESSAGE);
		this.setCanReorderRecords(DEFAULT_SELECTION_CAN_REORDER_MESSAGES);
		this.setCanDragRecordsOut(DEFAULT_CAN_DRAG_RECORDS);
		this.setCanAcceptDroppedRecords(DEFAULT_CAN_DRAG_RECORDS);
		this.setEditEvent(ListGridEditEvent.DOUBLECLICK);
		this.setListEndEditAction(RowEndEditAction.STOP);
		
		emailField = new ListGridField(emailFieldName, emailFieldLabel);
		emailField.setCanEdit(true);
		
		RegExpValidator emailValidator = new RegExpValidator();  
		emailValidator.setExpression(EMAIL_REG_EXP);
		emailValidator.setErrorMessage(DEFAULT_VALIDATION_MESSAGE);
		emailField.setValidators(emailValidator);
		
		
		removeField = new ListGridField("remove-field", "",25);
		removeField.setAlign(Alignment.CENTER);
		removeField.setType(ListGridFieldType.ICON);
		removeField.setCellIcon("actions/delete.png");
		removeField.setIsRemoveField(true);
		removeField.setCanHide(false);
		removeField.setCanReorder(false);
		removeField.setCanDragResize(false);
		removeField.setCanFreeze(false);
		removeField.setCanGroupBy(false);
		removeField.setCanSort(false);
		removeField.setCanEdit(false);
		removeField.setShowDefaultContextMenu(false);
		
		
		this.setFields(emailField,removeField);
		
		emailField.addEditorExitHandler(new EditorExitHandler(){

			@Override
			public void onEditorExit(EditorExitEvent event) {
				notifyListGridContentChangedHandlers(getRecords());
				
			}
			
			
		});
		
		this.addRecordClickHandler(new RecordClickHandler(){

			@Override
			public void onRecordClick(RecordClickEvent event) {
				if(event.getField().getName().equals("remove-field"))
				{
					endEditing();
				
					if(event.getRecord()== null)
					{
						Log.debug("Record was null");
					}
					removeData(event.getRecord());
					
				}
				
			}
		
		});
		
	}
	/**
	 * @return the emailField
	 */
	public ListGridField getEmailField() {
		return emailField;
	}
	
	public String getEmailFieldName() {
		return emailField.getName();
	}

	
	@Override
	public void removeData(Record record)
	{
		super.removeData(record);
		notifyListGridContentChangedHandlers(this.getRecords());

	}
	
	
	public HandlerRegistration addListGridContentChangedHandler(ListGridContentChangedHandler handler)
	{
		this.contentChangeHandlers.add(handler);
		return new ListGridContentChangedHandlerRegistration(handler);
	}
	
	
	public void notifyListGridContentChangedHandlers(ListGridRecord[] listGridRecords)
	{
		for(ListGridContentChangedHandler handler : contentChangeHandlers)
		{
			handler.onContentChange(new ListGridContentChangedEvent(listGridRecords));
		}
	}
	
	
	private class ListGridContentChangedHandlerRegistration implements HandlerRegistration
	{
		
		protected ListGridContentChangedHandler handler;
		
		public ListGridContentChangedHandlerRegistration(ListGridContentChangedHandler handler)
		{
			this.handler = handler;
		}

		@Override
		public void removeHandler() {
			contentChangeHandlers.remove(handler);
		}
	}
}

The salient part:

this.addRecordClickHandler(new RecordClickHandler(){

			@Override
			public void onRecordClick(RecordClickEvent event) {
				if(event.getField().getName().equals("remove-field"))
				{
					endEditing();
				
					if(event.getRecord()== null)
					{
						Log.debug("Record was null");
					}
					removeData(event.getRecord());
					
				}
				
			}
		
		});

[SiccoNaets]

Edit: I was able in the end to remove the record in question by doing this:

this.addRecordClickHandler(new RecordClickHandler(){

			@Override
			public void onRecordClick(RecordClickEvent event) {
				if(event.getField().getName().equals("remove-field"))
				{
				
					if(event.getRecord()== null)
					{
						Log.debug("Record was null");
						discardEdits(event.getRecordNum(), 0, false);
					}
					else
					{
						endEditing();
						removeData(event.getRecord());
					}
					
				}
				
			}
		
		});

Not sure if that's the right approach? seems to work ok....

[svjard]

Is this a non-databound grid? Are you talking about you have a record already added, you try to modify it with an invalid value or this is a brand new record from startEditingNew()?

[SiccoNaets]

Hey Svjard,

yes, it's a non-databound grid (I'm processing the contents of the grid manually by extracting all the emails and just passing them to the Form as an array).

And the record is new; i.e. the user clicks a button which calls ListGrid.startEditingNew();

[svjard]

OK then its not a bug, edits are handled differently, they have to be saved before they are part of the record list. You should be doing it the way you posted in your second post.

[SiccoNaets]

Gotcha, thanks for the response!