Custom HTML Tags
It's nice that I can add unknown HTML tags and cause the IDE to recognize that these are not errors but I wish for the following:
Select which attributes apply to which custom tags
Basically I'd like to see a popup with a text area for the tag name, button for whether or not case sensitivity is an issue, list box with attributes associated with this tag. Each attribute would have a custom dialog allowing you to specify if the name was case sensitive, the type of content allowed in the attribute value and if we're pushing it a regular expression field for validation. Finally I'd like to see a check box stating whether or not the tag may have a body and if so then some more options as to what tags are allowed in the body or which language syntax and ruleset IDEA should use for the body of that tag.
User Defined File Types
For tag based languages perhaps the allowance of a DTD or Schema upload as a base would be great. Then allowing us to specify to IDEA which highlighting should be used for CDATA areas defaulting to regular text for anything not indicated by the user.
Is there a way to manually write custom highlighting for our own file types at the moment? Where can I find this information?