Distinguish zscript from EL

This documentation is for an older version of ZK. For the latest one, please click here.

Keep in mind, EL is enclosed by ${}.

${self.label} is EL.

<window>	
	<button label="ok" id="${self.label}"/>
	${ok.label}		
</window>

alert(self.label) is not EL, it's a piece of zscript

<window>	
	<button label="ok" onClick='alert(self.label)'/>		
</window>

Although they both look alike, but EL and zscript have different life cycle, EL is not available at certain phase. Therefore in some cases, you can't use EL but zscript.

<window>	
	<!-- It's wrong, for java don't accept syntax as ${}-->
	<button label="ok" onClick='alert(${self.label})'/>		
</window>