[Mono-dev] vo.getAttribute is not a function (WebUIValidation*.js bug)

joel reed joel.reed at ddiworld.com
Wed Jan 3 09:41:33 EST 2007

The following patch fixes a bug in the web validation js files:


The "bug" is more like a quality of implementation issue. Basically, the 
patch changes all occurrences of

"for (var v in myArray)"


"for (var v=0; v < myArray.length; v++)"

Without this change, aspx pages using prototype.js 
(http://prototype.conio.net/), a popular ajax javascript library, will 
fail with a "vo.getAttribute is not a function" javascript error on 
mono. On Microsoft's .Net, they work just fine.

I have attached a sample html file and a copy of prototype.js which 
demonstrate why this happens. prototype.js extends the array class (see 
which causes "for (var v in myArray)" to loop over not just the DOM 
elements with validation functions, but also the extended functions of 
the Array.prototype. This leads to the "vo.getAttribute is not a 
function" javascript error, when the loop tries to call getAttribute on 
the "each" function.

To fix this problem, I switched to the syntax "for (var v=0; v < 
myArray.length; v++)", which doesn't loop over the extended function set.

To reiterate: the ASPX pages which originally surfaced this issue work 
on Microsoft's .Net platform, but not on mono. With the attached patch, 
the ASPX pages work on mono.

OK to apply?

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