Adding attributes to a tag using htmlpurifier

[rosswaycaster]

I am trying to use HTMLPurifier to transform HTML by adding class attributes to paragraphs.For example, for this input HTML:\[code\]<p>This is a paragraph</p><p>Another one</p>\[/code\]This would be the output:\[code\]<p class="myclass">This is a paragraph</p><p class="myclass">Another one</p>\[/code\]I read the doc and some forum post on that site but i could not figure it out how exactly I should do it?Thanks in advance.