Should Shortcode Attributes Allow HTML Special Characters?

[miqrogroove]

This question has a history of going unanswered.

In the Codex at ​http://codex.wordpress.org/Shortcode_API there is no mention of using HTML elements or any special characters within shortcode attributes. I added a section about syntax and left this feature as "unofficially allowed."

In the unit tests under the Tests_Shortcode class, there are no tests that mention any HTML special characters inside of shortcodes.

In #28564 we agreed it would make sense to not break HTML elements where they are already being used inside of attributes.

In #29608 and #29658 we are seeing reports of unencoded angle braces and ampersands being used inside of shortcode attributes, which were broken in 4.0.

In #29557 the shortcode HTML filter will likely be removed to fix this and other problems in 4.0.1.

So the issues involve documentation, unit tests, and questions about how this is supposed to work in the visual editor.

[miqrogroove]

Now see #29810 for a proposal to restrict HTML usage in sensitive areas.

[miqrogroove]

If you are looking for information about version 3.9.3 or 4.0.1, you might find it in these updates:

​http://codex.wordpress.org/Shortcode_API#HTML
​http://codex.wordpress.org/Shortcode_API#Unregistered_Names

[wonderboymusic]

Bump

[miqrogroove]

I'm working on a roadmap that includes this.