How to let Eclipse accept the canvas tag?

Question

I installed the Aptana plugin in my Eclipse, and I use canvas tag in my html file. I find that the Eclipse can't recognize the canvas tag, it highlight my canvas tags, and display follow msg:

< canvas > is not recognized

How can I fix this problem? thx in advance.

Answer 1

This is most likely coming from the Tidy HTML validator packaged with Aptana's version of Eclipse. If you open the preferences for your HTML browser within Aptana, you can add a regular expression to filter the validation errors.

This can be done by going to the Window > Preferences dialog window. Then, expand Aptana > HTML and select 'Validation'.

The filter would probably look like this:

.*<canvas> is not recognized.*

Answer 2

The specific rule under the Aptana>Editors>HTML>Validation filter is

.*<\s*canvas\s*> is not recognized.*

Doing something more generic like .* is not recognized.* lets any Bad Tag in

Answer 3

The answer, in clear terms, is to go to the HTML>Validation view under preferences as Malaxeur said (for Aptana2 on OSX it was Aptana Studio>Preferences, then Aptana>Editors>HTML>Validation), and create a new rule that resembles the following.

.* is not recognized.*

that's what worked for me. how or why it works, i can't explain.

Answer 4

The error will disappear if using the HTML5 doctype and a more recent version of Eclipse. I'm running Eclipse IDE for Java EE Developers (Build id: 20110218-0911) and do not have this issue.

Answer 5

I think it's already fixed in the current Aptana 3 beta. But in Aptana 2 it's still a problem. To allow not all, but multiple HTML5 Tags you could do it with a filter rule like that:

<(nav|header|section|article|canvas)> is not recognized.

Of course there are some more tags to consider. Just add the ones you need.