Is it alright to add custom Html attributes?

Question

I have a site I\'m working on where I want to mark if a row of data has been changed. If something has been changed in that row I would mark it with a custom attribute like

Answer 1

I believe that there is not a "Yes" or "No" answer to your question. Using custom attributes will help you have cleaner and shorter code in many circumstances. Your example is trivial and I believe that it can't demonstrate the power and flexibility of this technique. Specifically you are dealing with a boolean attribute, which most likely has to do with appearance. These kind of things are better handled with a class. However, with custom attributes you could add context to your nodes. You could use this context to do some calculations. For example, add a price or a weight attribute to the nodes of the list. You then later use these fields to calculate the sum or average. I am sure that there are many better than this examples out there.

On the other hand custom attributes will prevent the html from passing validation testing. This is an important problem and it may get even more important in the future.