Jquery custom attributes

Question

You can do this, use data- attributes though (part of the HTML5 specification), like this:

<li data-something="CommonLi"></li> 

jQuery even has built-in support for these in 1.4.3+, for example:

$("li").data("something") //"CommonLi"

For your other questions:

• They'll validate if it's HTML5 - but won't break anything in HTML4
• This shouldn't interfere with the designer, but it'll depend on which designer
• If you're fetching from an element, the performance is the same as any other attribute

if you're planning to have several attribute I suggest to set a unique namespaced attribute, e.g.

<li data-yourapp>...</li>

and use that attribute like an hashtable

$("li").data("yourapp", { 
   points  : 2000,
   life    : 1,
   weapons : {
      firegun  : 0,
      missiles : 12
   }
});

in this way you will reduce element access and you will retrieve all custom data once

I would personally recommend you to using jquery builtin method for saving data with each element. following is the code snippet for saving data:

$("ul").data("CommonUl");
$("li").data("CommonLi");