@Override
	public String getAsText() {
		Resource value = (Resource) getValue();
		try {
			// Try to determine URL for resource.
			return (value != null ? value.getURL().toExternalForm() : "");
		}
		catch (IOException ex) {
			// Couldn't determine resource URL - return null to indicate
			// that there is no appropriate text representation.
			return null;
		}
	}