diff --git a/core/includes/theme.inc b/core/includes/theme.inc
index 13a5154..6c9bb8f 100644
--- a/core/includes/theme.inc
+++ b/core/includes/theme.inc
@@ -119,7 +119,7 @@ function drupal_theme_rebuild() {
*/
function drupal_find_theme_functions($cache, $prefixes) {
$implementations = [];
- $grouped_functions = drupal_group_functions_by_prefix();
+ $grouped_functions = \Drupal::service('theme.registry')->getPrefixGroupedUserFunctions();
foreach ($cache as $hook => $info) {
foreach ($prefixes as $prefix) {
@@ -166,25 +166,6 @@ function drupal_find_theme_functions($cache, $prefixes) {
}
/**
- * Group all user functions by word before first underscore.
- *
- * @return array
- * Functions grouped by the first prefix.
- */
-function drupal_group_functions_by_prefix() {
- $functions = get_defined_functions();
-
- $grouped_functions = [];
- // Splitting user defined functions into groups by the first prefix.
- foreach ($functions['user'] as $function) {
- list($first_prefix,) = explode('_', $function, 2);
- $grouped_functions[$first_prefix][] = $function;
- }
-
- return $grouped_functions;
-}
-
-/**
* Allows themes and/or theme engines to easily discover overridden templates.
*
* @param $cache
diff --git a/core/lib/Drupal/Core/Theme/Registry.php b/core/lib/Drupal/Core/Theme/Registry.php
index bb89707..33d880b 100644
--- a/core/lib/Drupal/Core/Theme/Registry.php
+++ b/core/lib/Drupal/Core/Theme/Registry.php
@@ -138,6 +138,20 @@ class Registry implements DestructableInterface {
protected $themeManager;
/**
+ * User functions grouped by the word before the first underscore.
+ *
+ * @var array
+ */
+ protected $groupedFunctions = [];
+
+ /**
+ * All user-defined functions that have been added to groupedFunctions.
+ *
+ * @var array
+ */
+ protected $seenFunctions = [];
+
+ /**
* Constructs a \Drupal\Core\Theme\Registry object.
*
* @param string $root
@@ -342,9 +356,12 @@ protected function build() {
$this->processExtension($cache, $this->theme->getEngine(), 'theme_engine', $this->theme->getName(), $this->theme->getPath());
}
- // Finally, hooks provided by the theme itself.
+ // Hooks provided by the theme itself.
$this->processExtension($cache, $this->theme->getName(), 'theme', $this->theme->getName(), $this->theme->getPath());
+ // Discover and add all preprocess functions for theme hook suggestions.
+ $this->postProcessExtension($cache, $this->theme);
+
// Let modules and themes alter the registry.
$this->moduleHandler->alter('theme_registry', $cache);
$this->themeManager->alterForTheme($this->theme, 'theme_registry', $cache);
@@ -556,14 +573,117 @@ protected function processExtension(array &$cache, $name, $type, $theme, $path)
$cache[$hook]['preprocess functions'][] = $name . '_preprocess_' . $hook;
$cache[$hook]['theme path'] = $path;
}
- // Ensure uniqueness.
- $cache[$hook]['preprocess functions'] = array_unique($cache[$hook]['preprocess functions']);
}
}
}
}
/**
+ * Completes the theme registry adding discovered functions and hooks.
+ *
+ * @param array $cache
+ * The theme registry.
+ * @param \Drupal\Core\Theme\ActiveTheme $theme
+ * Current active theme.
+ *
+ * @see ::processExtension()
+ */
+ protected function postProcessExtension(array &$cache, ActiveTheme $theme) {
+ $grouped_functions = $this->getPrefixGroupedUserFunctions();
+
+ // Gather prefixes. This will be used to limit the found functions to the
+ // expected naming conventions.
+ $prefixes = array_keys((array) $this->moduleHandler->getModuleList());
+ foreach (array_reverse($theme->getBaseThemes()) as $base) {
+ $prefixes[] = $base->getName();
+ }
+ if ($theme->getEngine()) {
+ $prefixes[] = $theme->getEngine() . '_engine';
+ }
+ $prefixes[] = $theme->getName();
+
+ // Collect all variable preprocess functions in the correct order.
+ $suggestion_level = [];
+ $matches = [];
+ // Look for functions named according to the pattern and add them if they
+ // have matching hooks in the registry.
+ foreach ($prefixes as $prefix) {
+ // Grep only the functions which are within the prefix group.
+ list($first_prefix,) = explode('_', $prefix, 2);
+ if (!isset($grouped_functions[$first_prefix])) {
+ continue;
+ }
+ // Add the function and the name of the associated theme hook to the list
+ // of preprocess functions grouped by suggestion specificity if a matching
+ // base hook is found.
+ foreach ($grouped_functions[$first_prefix] as $candidate) {
+ if (preg_match("/^{$prefix}_preprocess_(((?:[^_]++|_(?!_))+)__.*)/", $candidate, $matches)) {
+ if (isset($cache[$matches[2]])) {
+ $level = substr_count($matches[1], '__');
+ $suggestion_level[$level][$candidate] = $matches[1];
+ }
+ }
+ }
+ }
+
+ // Add missing variable preprocessors. This is needed for hooks that do not
+ // explicitly register the hook. For example, when a theme contains a
+ // variable preprocess function but it does not implement a template, it
+ // will go missing. This will add the expected function. It also allows
+ // modules or themes to have a variable process function based on a pattern
+ // even if the hook does not exist.
+ for ($level = 1; $level <= count($suggestion_level); $level++) {
+ foreach ($suggestion_level[$level] as $preprocessor => $hook) {
+ if (isset($cache[$hook]['preprocess functions']) && !in_array($hook, $cache[$hook]['preprocess functions'])) {
+ // Add missing preprocessor to existing hook.
+ $cache[$hook]['preprocess functions'][] = $preprocessor;
+ }
+ elseif (!isset($cache[$hook]) && strpos($hook, '__')) {
+ // Process non-existing hook and register it.
+ // Look for a previously defined hook that is either a less specific
+ // suggestion hook or the base hook.
+ $previous_hook = $hook;
+ while (!isset($cache[$previous_hook]) && $pos = strrpos($previous_hook, '__')) {
+ $previous_hook = substr($previous_hook, 0, $pos);
+ // If base hook exists clone of it for the preprocess function
+ // without a template.
+ // @see https://www.drupal.org/node/2457295
+ if (isset($cache[$previous_hook])) {
+ $cache[$hook] = $cache[$previous_hook];
+ // If a base hook isn't set, this is the actual base hook.
+ if (!isset($cache[$previous_hook]['base hook'])) {
+ $cache[$hook]['base hook'] = $previous_hook;
+ }
+ $cache[$hook]['preprocess functions'][] = $preprocessor;
+ }
+ }
+ }
+ }
+ }
+ // Inherit all base hook variable preprocess functions into suggestion hooks.
+ // This ensures that derivative hooks have a complete set of variable
+ // preprocess functions.
+ foreach ($cache as $hook => $info) {
+ // The 'base hook' is only applied to derivative hooks already registered
+ // from a pattern. This is typically set from
+ // drupal_find_theme_functions() and drupal_find_theme_templates().
+ if (isset($info['base hook']) && isset($cache[$info['base hook']]['preprocess functions'])) {
+ $diff = array_diff($info['preprocess functions'], $cache[$info['base hook']]['preprocess functions']);
+ $cache[$hook]['preprocess functions'] = array_merge($cache[$info['base hook']]['preprocess functions'], $diff);
+ }
+
+ // Optimize the registry.
+ if (isset($cache[$hook]['preprocess functions']) && empty($cache[$hook]['preprocess functions'])) {
+ unset($cache[$hook]['preprocess functions']);
+ }
+ // Ensure uniqueness.
+ if (isset($cache[$hook]['preprocess functions'])) {
+ $cache[$hook]['preprocess functions'] = array_unique($cache[$hook]['preprocess functions']);
+ }
+ }
+ }
+
+ /**
* Invalidates theme registry caches.
*
* To be called when the list of enabled extensions is changed.
@@ -590,6 +710,34 @@ public function destruct() {
}
/**
+ * Gets all user functions grouped by the word before the first underscore.
+ *
+ * @return array
+ * Functions grouped by the first prefix.
+ */
+ public function getPrefixGroupedUserFunctions() {
+ $functions = get_defined_functions();
+
+ // Splitting user defined functions into groups by the first prefix.
+ foreach ($functions['user'] as $function) {
+ if (isset($this->seenFunctions[$function])) {
+ continue;
+ }
+ list($first_prefix,) = explode('_', $function, 2);
+ $this->groupedFunctions[$first_prefix][] = $function;
+ }
+
+ // The theme registry may load new code. On encountering newly defined
+ // functions, we save the list of defined functions again. This works
+ // because functions cannot disappear between calls.
+ if (isset($first_prefix)) {
+ $this->seenFunctions = array_fill_keys($functions['user'], TRUE);
+ }
+
+ return $this->groupedFunctions;
+ }
+
+ /**
* Wraps drupal_get_path().
*
* @param string $module
diff --git a/core/lib/Drupal/Core/Theme/ThemeManager.php b/core/lib/Drupal/Core/Theme/ThemeManager.php
index 6850fcb..687ae54 100644
--- a/core/lib/Drupal/Core/Theme/ThemeManager.php
+++ b/core/lib/Drupal/Core/Theme/ThemeManager.php
@@ -286,12 +286,10 @@ protected function theme($hook, $variables = array()) {
include_once $this->root . '/' . $include_file;
}
}
- // Replace the preprocess functions with those from the base hook.
if (isset($base_hook_info['preprocess functions'])) {
// Set a variable for the 'theme_hook_suggestion'. This is used to
// maintain backwards compatibility with template engines.
$theme_hook_suggestion = $hook;
- $info['preprocess functions'] = $base_hook_info['preprocess functions'];
}
}
if (isset($info['preprocess functions'])) {
diff --git a/core/modules/system/src/Tests/Theme/ThemeTest.php b/core/modules/system/src/Tests/Theme/ThemeTest.php
index e62a199..8275dd5 100644
--- a/core/modules/system/src/Tests/Theme/ThemeTest.php
+++ b/core/modules/system/src/Tests/Theme/ThemeTest.php
@@ -277,7 +277,7 @@ function testPreprocessHtml() {
/**
* Tests that region attributes can be manipulated via preprocess functions.
*/
- function testRegionClass() {
+ public function testRegionClass() {
\Drupal::service('module_installer')->install(array('block', 'theme_region_test'));
// Place a block.
@@ -287,4 +287,31 @@ function testRegionClass() {
$this->assertEqual(count($elements), 1, 'New class found.');
}
+ /**
+ * Ensures suggestion preprocess functions run for default implementations.
+ *
+ * The theme hook used by this test has its base preprocess function in a
+ * separate file, so this test also ensures that that file is correctly loaded
+ * when needed.
+ */
+ public function testSuggestionPreprocessForDefaults() {
+ \Drupal::service('theme_handler')->setDefault('test_theme');
+ // Test with both an unprimed and primed theme registry.
+ drupal_theme_rebuild();
+ for ($i = 0; $i < 2; $i++) {
+ $this->drupalGet('theme-test/preprocess-suggestions');
+ $items = $this->cssSelect('.suggestion');
+ $expected_values = [
+ 'Suggestion',
+ 'Kitten',
+ 'Monkey',
+ 'Kitten',
+ 'Flamingo',
+ ];
+ foreach ($expected_values as $key => $value) {
+ $this->assertEqual((string) $value, $items[$key]);
+ }
+ }
+ }
+
}
diff --git a/core/modules/system/tests/modules/theme_test/src/ThemeTestController.php b/core/modules/system/tests/modules/theme_test/src/ThemeTestController.php
index a8f16c6..68b627e 100644
--- a/core/modules/system/tests/modules/theme_test/src/ThemeTestController.php
+++ b/core/modules/system/tests/modules/theme_test/src/ThemeTestController.php
@@ -143,4 +143,25 @@ public function nonHtml() {
return new JsonResponse(['theme_initialized' => $theme_initialized]);
}
+ /**
+ * Controller for testing preprocess functions with theme suggestions.
+ */
+ public function preprocessSuggestions() {
+ return [
+ [
+ '#theme' => 'theme_test_preprocess_suggestions',
+ '#foo' => 'suggestion',
+ ],
+ [
+ '#theme' => 'theme_test_preprocess_suggestions',
+ '#foo' => 'kitten',
+ ],
+ [
+ '#theme' => 'theme_test_preprocess_suggestions',
+ '#foo' => 'monkey',
+ ],
+ ['#theme' => 'theme_test_preprocess_suggestions__kitten__flamingo'],
+ ];
+ }
+
}
diff --git a/core/modules/system/tests/modules/theme_test/templates/theme-test-preprocess-suggestions.html.twig b/core/modules/system/tests/modules/theme_test/templates/theme-test-preprocess-suggestions.html.twig
new file mode 100644
index 0000000..512613d
--- /dev/null
+++ b/core/modules/system/tests/modules/theme_test/templates/theme-test-preprocess-suggestions.html.twig
@@ -0,0 +1,4 @@
+{{ foo }}
+{% if bar %}
+ {{ bar }}
+{% endif %}
diff --git a/core/modules/system/tests/modules/theme_test/theme_test.module b/core/modules/system/tests/modules/theme_test/theme_test.module
index 7ba5c2d..8b820c3 100644
--- a/core/modules/system/tests/modules/theme_test/theme_test.module
+++ b/core/modules/system/tests/modules/theme_test/theme_test.module
@@ -55,6 +55,12 @@ function theme_test_theme($existing, $type, $theme, $path) {
$info['test_theme_not_existing_function'] = array(
'function' => 'test_theme_not_existing_function',
);
+ $items['theme_test_preprocess_suggestions'] = [
+ 'variables' => [
+ 'foo' => '',
+ 'bar' => '',
+ ],
+ ];
return $items;
}
@@ -90,6 +96,27 @@ function theme_theme_test_function_template_override($variables) {
}
/**
+ * Implements hook_theme_suggestions_HOOK().
+ */
+function theme_test_theme_suggestions_theme_test_preprocess_suggestions($variables) {
+ return ['theme_test_preprocess_suggestions__' . $variables['foo']];
+}
+
+/**
+ * Implements hook_preprocess_HOOK().
+ */
+function theme_test_preprocess_theme_test_preprocess_suggestions(&$variables) {
+ $variables['foo'] = 'Theme hook implementor=theme_theme_test_preprocess_suggestions().';
+}
+
+/**
+ * Tests a module overriding a default hook with a suggestion.
+ */
+function theme_test_preprocess_theme_test_preprocess_suggestions__monkey(&$variables) {
+ $variables['foo'] = 'Monkey';
+}
+
+/**
* Prepares variables for test render element templates.
*
* Default template: theme-test-render-element.html.twig.
diff --git a/core/modules/system/tests/modules/theme_test/theme_test.routing.yml b/core/modules/system/tests/modules/theme_test/theme_test.routing.yml
index 2dbd188..1ff61cf 100644
--- a/core/modules/system/tests/modules/theme_test/theme_test.routing.yml
+++ b/core/modules/system/tests/modules/theme_test/theme_test.routing.yml
@@ -103,3 +103,10 @@ theme_test.non_html:
_controller: '\Drupal\theme_test\ThemeTestController::nonHtml'
requirements:
_access: 'TRUE'
+
+theme_test.preprocess_suggestions:
+ path: '/theme-test/preprocess-suggestions'
+ defaults:
+ _controller: '\Drupal\theme_test\ThemeTestController::preprocessSuggestions'
+ requirements:
+ _access: 'TRUE'
diff --git a/core/modules/system/tests/themes/test_theme/templates/theme-test-preprocess-suggestions--suggestion.html.twig b/core/modules/system/tests/themes/test_theme/templates/theme-test-preprocess-suggestions--suggestion.html.twig
new file mode 100644
index 0000000..e77924d
--- /dev/null
+++ b/core/modules/system/tests/themes/test_theme/templates/theme-test-preprocess-suggestions--suggestion.html.twig
@@ -0,0 +1 @@
+{{ foo }}
diff --git a/core/modules/system/tests/themes/test_theme/test_theme.theme b/core/modules/system/tests/themes/test_theme/test_theme.theme
index 9350755..2c7bf96 100644
--- a/core/modules/system/tests/themes/test_theme/test_theme.theme
+++ b/core/modules/system/tests/themes/test_theme/test_theme.theme
@@ -105,3 +105,34 @@ function test_theme_theme_test_function_suggestions__module_override($variables)
function test_theme_theme_registry_alter(&$registry) {
$registry['theme_test_template_test']['variables']['additional'] = 'value';
}
+
+/**
+ * Tests a theme overriding a default hook with a suggestion.
+ *
+ * Implements hook_preprocess_HOOK().
+ */
+function test_theme_preprocess_theme_test_preprocess_suggestions(&$variables) {
+ $variables['foo'] = 'Theme hook implementor=test_theme_preprocess_theme_test_preprocess_suggestions().';
+}
+
+/**
+ * Tests a theme overriding a default hook with a suggestion.
+ */
+function test_theme_preprocess_theme_test_preprocess_suggestions__suggestion(&$variables) {
+ $variables['foo'] = 'Suggestion';
+}
+
+/**
+ * Tests a theme overriding a default hook with a suggestion.
+ */
+function test_theme_preprocess_theme_test_preprocess_suggestions__kitten(&$variables) {
+ $variables['foo'] = 'Kitten';
+}
+
+/**
+ * Tests a theme overriding a default hook with a suggestion.
+ */
+function test_theme_preprocess_theme_test_preprocess_suggestions__kitten__flamingo(&$variables) {
+ $variables['bar'] = 'Flamingo';
+}
+