[jira] [Created] (WW-4532) Javascript generated by s:doubleselect has global variables that can interfer with the rest of the app

["Pierre Henry (JIRA)" <ji...@apache.org>]

Pierre Henry created WW-4532:
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             Summary: Javascript generated by s:doubleselect has global variables that can interfer with the rest of the app
                 Key: WW-4532
                 URL: https://issues.apache.org/jira/browse/WW-4532
             Project: Struts 2
          Issue Type: Bug
          Components: Plugin - Tags
    Affects Versions: 2.3.20
            Reporter: Pierre Henry


In the JavaScript code generated by the {{s:doubleselect}} tag (and, possibly other tags), there are for loops using the following format :

{code}
for (m = ObservationForm_observation_countryKeyTemp.options.length - 1; m >= 0; m--) {
            ObservationForm_observation_countryKeyTemp.options[m] = null; {code}

The variable {{m}} is never defined before that. So this creates a globally scoped {{m}} variable that can interfere with other JavaScript code.

In my case it interfered with library code that is processed with a minifyer (I think in this case it is Google Closure Compiler) and contains a lot of one-letter variable name, such as... {{m}}.

So I got the following error :

{code}
Uncaught TypeError: number is not a function
{code}

Which was difficult to trace since the code was minified. If the code was not minified, then the error did not happen any more.

I believe it would be enough to just use the var keyword in the loop definition to remove this problem :

{code}
for (var m = ObservationForm_observation_countryKeyTemp.options.length - 1; m >= 0; m--) {
            ObservationForm_observation_countryKeyTemp.options[m] = null; {code}





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