Bug 121352 The data set binding property cannot be retrieved in report preview layout
In report preview page, the datasource/dataset property binding lists cannot be retrieved. The dataset binding can not work correctly in layout preview because it's value cannot get from the binding list. But in the data set edit page, the binding value can be got. You can refer to the attachment.
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/core/DesignElement.java
protected String limitStringLength( String displayLabel )
	{
		if ( displayLabel == null )
			return null;
		if ( displayLabel.length( ) > MAX_DISPLAY_LABEL_LEN )
		{
			displayLabel = displayLabel.substring( 0, MAX_DISPLAY_LABEL_LEN );
			int pos = displayLabel.lastIndexOf( " " ); 
			if ( pos != -1 )
			{
				displayLabel = displayLabel.substring( 0, pos );
			}
			return displayLabel + "..."; 
		}
		return displayLabel;
	}
	/**
	 * Generates a clone copy of this element. When a report element is cloned,
	 * the basic principle is just copying the property value into the clone,
	 * the other things, like container references, child list references,
	 * listener references will not be cloned; that is, the clone is isolated
	 * from the design tree until it is added into a target design tree.
	 * 
	 * <p>
	 * When inserting the cloned element into the design tree, user needs to
	 * care about the element name confliction; that is, the client needs to
	 * call the method
	 * <code>{@link ReportDesignHandle#rename( DesignElementHandle )}</code>
	 * to change the element names.
	 *