When elAttribute=class, it should check if the previousValue is undefined

[kadishmal]

Basically this line https://github.com/theironcook/Backbone.ModelBinder/blob/master/Backbone.ModelBinder.js#L400 is not completely correct:

if(!_.isUndefined(previousValue) || !_.isUndefined(currentValue)){
    previousValue = this._getConvertedValue(Backbone.ModelBinder.Constants.ModelToView, elementBinding, previousValue);
    el.removeClass(previousValue);
}

It should be:

previousValue && el.removeClass(previousValue);

That is it should check whether the previousValue is not undefined. If it is, then el.removeClass(undefined) will remove all the classes previously defined for some other purposes. Imagine I have an icon defined as <i class="fa fa-envelope"/>. If previousValue=undefined, then it will remove fa fa-envelope classes completely so the element will end up being <i class=""/>.

[platinumazure]

I think this is caused by a change in the behavior of removeClass in jQuery, incidentally.

[amakhrov]

In which version of jquery removeClass(undefined) removes all the element classes? I was not able to reproduce it with 1.10.2, 1.11.3

[platinumazure]

I think I had observed that behavior somewhere in the 1.8.x series. Maybe they've changed it again...? I guess I don't know if this issue is still valid.