Bug 165278 this.getDisplayContent()="" in script of text will destroy preview[0801]
Description: this.getDisplayContent()="" in script of text will destroy preview Build number:2.1.2.v20061120 and 2.2.0.v20061117 Steps to reproduce: 1. Insert a text item, select it and switch to script editor 2. Input this.getDisplayContent()="" and preview Expected result: Error message about the incorrect script. Actual result: In 2.1.2, I saw HTTP Status 500 - type Exception report message description The server encountered an internal error () that prevented it from fulfilling this request. In 2.2.0, I saw error dialog with java.lang.ClassCastException.
engine/org.eclipse.birt.report.engine/src/org/eclipse/birt/report/engine/executor/ExecutionContext.java
*/
	private List onPrepareErrors = new ArrayList( );
	/**
	 * Flag to indicate whether task is canceled.
	 */
	private boolean isCancelled = false;
	
	/**
	 * utilities used in the report execution.
	 */
	private HashMap stringFormatters = new HashMap( );
	private HashMap numberFormatters = new HashMap( );
	private HashMap dateFormatters = new HashMap( );
	private ClassLoader applicationClassLoader;
	
	private int MAX_ERRORS = 100;
	/**
	 * 
	 */
	private IDocArchiveReader dataSource;
	
	/**
	 * All page break listeners.
	 */
	private List pageBreakListeners;
	
	public ExecutionContext()
	{
		this(null, -1);
	}