wildcard handling for path aliases is broken

"it should also switch to this theme when the path ist foo-bar or foo-test or foo-anything-else, right?"
Simple answer is: No.

"even not when i try to specify a wildcard like foo%"
Wildcards in ThemeKey don't work like this. They work like drupal's menu system. You only can replace parts of the path with wildcards.
Example These are the possible wildcard replacements for foo/bar/test.html:

foo/bar/%
foo/%/test.html
%/bar/test.html
foo/%
%/bar/%
%/%/test.html
%/%
%

You can use the debug mode of ThemeKey Properties to display all these variants.

Nevertheless you can achieve the feature "foo%" you requested using this rule chain:

Property: drupal:path
Operator: =
Value: %foo

  Property: drupal:path:wildcard
  Wildcard: foo
  Operator: ~
  Value: /^foo.*/

You discovered two bugs:
1. '~' should be allowed for drupal:path:wildcard (I already fixed that locally)
2. Switching like I suggested doesn't work if this url is an alias for a node (I'll have a closer look at this now)

OK, it's fixed. If you want to you can apply the attached patch. But I will release a new version of ThemeKey soon ...

And here's a screenshot that shows how your rule chain should look like.

what is the ~ operator? tried googling and nothing came up.. im still a bit confused about the wildcard thing. any more simple examples?

thanks!

All operators are documented in the help section of the ThemeKey module. And also in the descriptions above the rule chain.

"~" is the regex operator.

Wildcards for paths have been discussed in the issue queue multiple times, p.e. #836638: Path wildcards does not seem to work.

Would be awesome to add some of this documentation or even just reference this ticket in the documentation of the module. This helped a LOT!

What i did not find clear in the instructions is that in order to use the wildcard settings, you have to use both a path and a wildcard path together. This post helped alot, but it still took some time to figure it out.

I needed to use themekey to change the theme for all nodes at node/[nid]/modal.

In order to accomplish this I needed two rules together.

Rule 1:
drupal:path = node/#nid/modal

Rule 2: (a child of Rule 1)
drupal:path:wildcard nid ~ /\d/

Essentially this takes the #nid in the first rule and applies the regex in the second rule. The trick was to name the wildcard. I needed '#nid' in Rule 1 and then I had to name the wildcard in rule 2 'nid'. So whatever you have as the wildcard in the first rule must have a name and that name must be used in the child rule.

Here's an example with 2 wildcards

Rule 1:
drupal:path = foo/#nid/%bar

Rule 2: (a child of rule 1)
drupal:path:wildcard nid ~ /\d/

Rule 3: (a child of rule 1)
drupal:path:wildcard bar ~ /comments|talk/

These rules would change the theme for any pages that have the following url structures:

• foo/[some node id]/comments
• foo/[some node id]/talk

I had no idea of the parent child relationship and I spent an hour figuring it out. Hopefully his might save someone else an hour.