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

["Lukasz Lenart (JIRA)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/WW-4532?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14644277#comment-14644277 ] 

Lukasz Lenart commented on WW-4532:
-----------------------------------

but {{var}} will define a global variable again - it'll be the same. I think it would be better to rename the variable and put it upfront.

> 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
>              Labels: javascript
>             Fix For: 2.5.x
>
>
> 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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