15
Jul
2011
MXML: “true && true” error
Stumbled across this strange error while doing some development. I’ve needed to determine the enable function of a button based on two boolean conditions and as a result created the following bit of code:
<com:Component enabled=”{booleanA && booleanB}”/>
The compiler didn’t like what I’ve put together and threw the following error: The entity name must immediately follow the ‘&’ in the entity reference.
At first I litteraly thought that I’ve forgotten how to code and trivially tried a simple if statement in a <fx:Script> tag – that worked without a problem. I’ve also tried to see if the or ”||” operator worked within the enabled attribute – which it did. My last thought before searching for a solution online was that the latest version of Adobe Flex had a bug in it.
Some of the solution that I’ve discovered are:
- use ;& instead
- use (booleanA) ? (booleanB):false
- use !(!active1 || !active2)
I found the third option to be quite amusing though in general the root cause of the problem is the XML parsing of the MXML code. Once you understand it should be straight forward.
Tags: coding, Flex, programming
