BUG - IE10+ selection performance fix

[Aaron]

All - we just had ran into an issue where the performance of row selection was painful in IE10+.  Looking on the forums, we saw that others have had issues with this and that it was "better" in the latest release.  The cause is apparently's IE's slow handling of the CSS ":not" selector.

We had to find a fix and believe we have traced it down to a problem in Kendo's code.  Basically, if you have a grid and you do NOT use Grouping or Footers, the code thinks you do and thus appends extra ":not" selectors to the CSS queries.  The fix for this assuming you DO NOT use grouping or footers is to set these templates to "".  The problem is Kendo does a !== "" check and if you don't define them and leave them undefined, it assumes you do have them.

Here is our code fix:

// Push the column info
columnInfo.push(
{
      // OMIT
      groupFooterTemplate: "",
       footerTemplate: ""
});

The offending code in Kendo is Line #26619 inside of _hasFooters


if (cols[j].footerTemplate !== "" || cols[j].groupFooterTemplate !== "") {
return true;
}

Hopefully this helps some.

[Nikolay Rusev]

Hello Aaron,

Indeed currently _hasFooters method always return `true` due to the reasons you describe in the post. We will do our best to address this for the official Q1 2014 release. 

Thank you for the feedback, we appreciate it.

Regards,
Nikolay Rusev
Telerik