Add an active_theme_path twig function

Comment from #2416831-6: Add an active_theme twig function applies here too I think.

Patch from #3 still applies, for the record :)

But the tests aren't postponed :) someone else can be working on those in the meantime.

Hit this today, as well. And was about to roll the exact same patch. ... And this one comes with tests also. Awesome. Looks good to me.

Also marking major per #2168231: Twig Functions needed in templates.

I think this is blocked on #2416831: Add an active_theme twig function for injecting the theme manager.

OK, the parent is in now. Now this just needs to be changed to use the injected theme manager.

Removing tags.

Attaching a re-roll of https://www.drupal.org/node/2416857#comment-9976363

Small conflict probably due to an extra space/new line. Marking as "Needs review".

@pjonckiere,

Epic nitpick. This newline is not needed. I guess this can be removed on commit?

Doh, missed that one. Not sure what you mean by removing on commit though?

Re-rolling my previous patch from https://www.drupal.org/node/2416857#comment-10370239 with amendments per https://www.drupal.org/node/2416857#comment-10370595. Also updated documentation for a couple methods to include the missing @throws declarations.

+++ b/core/tests/Drupal/Tests/Core/Template/TwigExtensionTest.php
@@ -190,5 +217,4 @@ public function __construct($string) {
-

This change shouldn't be in the patch. Commiter please remove this change :)

Does this get resolved into the compiled templates or is it done when the template is rendered?

I think it's the latter, but we really don't want the theme path compiled with the templates - moving directory would break it then.

#41: It is determined dynamically on run-time.

+++ b/core/lib/Drupal/Core/Template/TwigExtension.php
@@ -361,6 +372,8 @@ public function attachLibrary($library) {
+   *
+   * @throws \Exception

@@ -474,6 +487,8 @@ public function escapeFilter(\Twig_Environment $env, $arg, $strategy = 'html', $
+   *
+   * @throws \Exception

These changes are totally out-of-scope. Removed.

Committed 7594f7e and pushed to 8.0.x. Thanks!

Adding this was a grave mistake. See #2611246: [PP-1] Document the recommended method of creating file URLs to theme assets (e.g. images).

So it is smarter to not use this anymore and wait for the stream wrappers solution? I mean, is it possible that this active_theme function will disappear in the future?

I agree with Wim, here - this function doesn't return a path relative to the base path, and you may not necessarily have the base path in your twig template context. Stream wrappers are a much better solution.

But, since this is committed to core, that ship has (mostly) sailed. What's the process to get this marked as deprecated for 9.0?