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
return htmlConfig.getImageHandler( );
				}
			}
		}
		
		return null;
	}
	
	/**
	 * return application class loader.
	 * The application class loader is used to load the report item event handle and 
	 * java classes called in the javascript.
	 * @return class loader
	 */
	public ClassLoader getApplicationClassLoader( )
	{
		return applicationClassLoader;
	}
	/**
	 * the application class loader.
	 * 
	 * The class loader first try to the load the class as following sequence:
	 * <li>1. standard java class loader,
	 * <li>2. classloader setted through the appContext.
	 * <li>3. CLASSPATH setted by WEBAPP_CLASSPATH_KEY
	 * <li>4. PROJECT_CLASSPATH_KEY
	 * <li>5. WORKSAPCE_CLASSPATH_KEY
	 * <li>6. JARs define in the report design
	 */
	static private class ApplicationClassLoader extends ClassLoader