Issue #2301975 by kim.pepper: Move drupal_is_front_page to PathMatcher service.

core/includes/path.inc

@@ -15,20 +15,12 @@
  *
  * @return
  *   Boolean value: TRUE if the current page is the front page; FALSE if otherwise.
+ *
+ * @deprecated as of Drupal 8.0. Use
+ *   \Drupal\Core\Path\PathMatcherInterface::isFrontPage() instead.
  */
 function drupal_is_front_page() {
-  // Use the advanced drupal_static() pattern, since this is called very often.
-  static $drupal_static_fast;
-  if (!isset($drupal_static_fast)) {
-    $drupal_static_fast['is_front_page'] = &drupal_static(__FUNCTION__);
-  }
-  $is_front_page = &$drupal_static_fast['is_front_page'];
-
-  if (!isset($is_front_page)) {
-    $is_front_page = (current_path() == \Drupal::config('system.site')->get('page.front'));
-  }
-
-  return $is_front_page;
+  return \Drupal::service('path.matcher')->isFrontPage();
 }
 
 /**

core/lib/Drupal/Core/Path/PathMatcher.php

@@ -14,6 +14,13 @@
  */
 class PathMatcher implements PathMatcherInterface {
 
+  /**
+   * Whether the current page is the front page.
+   *
+   * @var bool
+   */
+  protected $isCurrentFrontPage;
+
   /**
    * The default front page.
    *
@@ -51,10 +58,6 @@ public function __construct(ConfigFactoryInterface $config_factory) {
   public function matchPath($path, $patterns) {
 
     if (!isset($this->regexes[$patterns])) {
-      // Lazy-load front page config.
-      if (!isset($this->frontPage)) {
-        $this->frontPage = $this->configFactory->get('system.site')->get('page.front');
-      }
       // Convert path settings to a regular expression.
       $to_replace = array(
         // Replace newlines with a logical 'or'.
@@ -67,11 +70,37 @@ public function matchPath($path, $patterns) {
       $replacements = array(
         '|',
         '.*',
-        '\1' . preg_quote($this->frontPage, '/') . '\2',
+        '\1' . preg_quote($this->getFrontPagePath(), '/') . '\2',
       );
       $patterns_quoted = preg_quote($patterns, '/');
       $this->regexes[$patterns] = '/^(' . preg_replace($to_replace, $replacements, $patterns_quoted) . ')$/';
     }
     return (bool) preg_match($this->regexes[$patterns], $path);
   }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function isFrontPage() {
+    // Cache the result as this is called often.
+    if (!isset($this->isCurrentFrontPage)) {
+      $this->isCurrentFrontPage = (current_path() == $this->getFrontPagePath());
+    }
+    return $this->isCurrentFrontPage;
+  }
+
+  /**
+   * Gets the current front page path.
+   *
+   * @return string
+   *   The front page path.
+   */
+  protected function getFrontPagePath() {
+    // Lazy-load front page config.
+    if (!isset($this->frontPage)) {
+      $this->frontPage = $this->configFactory->get('system.site')
+        ->get('page.front');
+    }
+    return $this->frontPage;
+  }
 }

core/lib/Drupal/Core/Path/PathMatcherInterface.php

@@ -25,4 +25,12 @@ interface PathMatcherInterface {
    */
   public function matchPath($path, $patterns);
 
+  /**
+   * Checks if the current page is the front page.
+   *
+   * @return bool
+   *   TRUE if the current page is the front page.
+   */
+  public function isFrontPage();
+
 }