Add .install file abilities for Themes

1+, For this feature. We definitely need this to modify configuration when the theme is been installed. There is not a way to do this right now, which make contrib theme to have module and/or profile as dependency.

which make contrib theme to have module and/or profile as dependency.

If we want that, I would suggest that themes can have dependencies to modules ... hacking that into install would make the experience in drush/console/composer worse than it would have to be.

chx explained me a bit more about it, sorry!

hook_theme_installed and hook_theme_enabled are mentioned as a @todo from #122 thru #145. After that hook_theme_enabled is implemented but there is no further mention of hook_theme_install. There are several comments as to the need for hook_theme_installed though.

Let's see how it goes

@dawehner,

#3

I'm not hacking the install with Drush/DrupalConsole instead after installing the theme we will recommend to run a script to import the configuration instead of doing manual work and/or having a module as dependency to import configuration.

Here is an example of what I was talking about - https://www.drupal.org/node/2652562

I was able to run hook_install/hook_uninstall inside of a theme.

best_theme_ever.install

<?php
function best_theme_ever_install(){
  drupal_set_message(t('hook_install work =))'), 'status');
}

function best_theme_ever_uninstall(){
  drupal_set_message(t('hook_uninstall work =))'), 'status');
}

Moving it to RTBC.

+++ b/core/lib/Drupal/Core/Render/theme.api.php
@@ -1273,5 +1273,21 @@ function hook_template_preprocess_default_variables_alter(&$variables) {
+ * Perform setup tasks when the theme is uninstalled.
+ *
+ * @see \Drupal\Core\Extension\ModuleInstaller::uninstall
+ */
+function hook_uninstall() {

For the uninstall could the docblock say "tear down" or something instead of "setup"?

Otherwise looks good, thanks!

Re-roll patch base on #9.

+++ b/core/lib/Drupal/Core/Extension/ThemeInstaller.php
@@ -213,6 +219,13 @@ public function install(array $theme_list, $install_dependencies = TRUE) {
+  protected function loadThemeInstallInc(Extension $theme) {

Needs documentation.

Moving to 8.1.x since it's an API addition.

Looks great apart from that though.

Relating a couple issues that have the general direction of making Themes have more features that modules have.

What about updates? We need this to run version updates.

Oh yeah, maybe we can actually move this to #187289: Support .install files for themes and get hook_update_N() and hook_install in one go at it?

I think this should be a duplicate of #474684: Allow themes to declare dependencies on modules - because theme project folders can already contain modules. Once you add dependencies, you get hook_install() (and updates, and everything else) for free.

See discussion in #2002606: Allow themes to provide services.yml also.

+1

@SKAUGHT Is this an RC target for 8.1.x?

I would hope so.

I currently am talking it back to needs work, as i've just touched up the summary, but realize the current patch doesn't directly include a routine for hook_requirements().

It may be too late for RC for this one.

i've been testing this patch. although is does currently allow for a theme to have a .install file and hook_install/uninstall it certainly does not magically pickup a hook_requirements, as is.

following the basic pattern of this patch i can get it to begin a _requirements callback. but then is it failing to properly respond to and $phase switch. Sadly, at this time, I can not see way to properly continue with this patch myself.

updating issue title.

Here is a patch rerolling.

I add an extra function inside theme.inc to provide better the require_once

Also I might consider this issue as a bug and not as a task. This features was wrongly removed and add the bug to don't support .install for themes.

I couldn't add a interdiff since the changes are from the 8.1.x branch and quite old.

Reroll.

I think it'd be more appropriate to simply proxy theme events via a ThemePluginManager (#2869859: [PP-1] Refactor theme hooks/registry into plugin managers) since themes aren't allowed to define services for events, see: https://cgit.drupalcode.org/plus/tree/src/ThemePluginManager.php?h=8.x-4....

Similar to #2206347: Use event system in ModuleHandler.

As a last resort, I agree with @catch in that #474684: Allow themes to declare dependencies on modules could assist with this... albeit, in a very indirect way.

Regardless, introducing .install files for themes now feels like a step backwards, not forwards.

I'm here as I was surprised to find that while themes can define default configuration, they cannot define update hooks to modify that configuration or install new configuration if needed. For example, I have a Drupal 9 platform with themes that provide default config entities for the Layout Builder Styles and CKEditor Standlone Styles modules. If I want to make changes or add new config entities for sites that already exist and use those themes, it seems my only hope is to create a module, make that module a dependency of the theme, and put the config and update hooks in there?