Upgrade jQuery 1.4.2 to 1.9.1

Question

We have been using jQuery 1.4.2 in our web application. Recently it was suggested that we upgrade to a newer version. So far we are thinking about upgrading to 1.9.1 as we n

Answer 1

In addition to frenchie's answer, if your application injects custom html attributes from code-behind, at the client-side those attributes can still only be read using attr() instead of the new prop().

According to my current understanding this is because name-value attribute additions to elements are only recognized as properties when they are either native to the DOM element type, or have been added using the same client-side jQuery prop() method.

Doing a similar jQuery upgrade for the first time, I found this thread about the differences between attr and the new prop a very interesting read: prop-vs-attr