Fix angular.element.cache memory leak

[Teemu]

After doing memory leak hunting in my application I found that ui-select is leaking memory. I'm not sure why this is exactly needed as I would have expected $compile to handle it (I tried looking at uiSelectDirective.js with no results)

[wesleycho]

This is a good catch - LGTM

[Teemu]

Thanks! 👏

[roman-savitski]

Cause an issue if ui-select is being toggled on page by ng-if.
<div ng-if="expression"> <ui-select>.....</ui-select> </div>
Sometimes this cause choices element to be removed forever.

In this case "compile" called only once, but "link" called each time ng-if is triggered. And I suppose this is the real reason of memory leak, because "link" is binded to "compile" function closure. When this change was made var choices=... was defined inside "link", but not its defined in "compile".

I propose:

• isolate "link" fn from "compile" scope return (function(groupByExp, groupFilterExp){ return function link(scope, element, attrs, $select){...} })(groupByExp, groupFilterExp);
• replace tElement usage with element
• replace choices.remove(); with element.querySelectorAll('.ui-select-choices-row').remove();

[user378230]

@raman-savitski If you want to report a bug you should open a new issue here on github and follow the issue template. (You can obviously reference this PR in your issue).

You or someone else can then submit a PR to resolve it 👍