Script Loader: Allow for wp_register_script() to be called after `w…

…p_enqueue_script()`.

When a plugin registers styles/scripts on `wp_enqueue_scripts` (as plugin authors are encouraged to do), and conditionally enqueues their script/style on `the_content` filter, things "just work". In block themes, `the_content` is run prior to the header being processed, which results in the above scenario failing.

This change makes a `wp_enqueue_script( 'example' ); wp_register_script( 'example' );` work, where as currently the enqueue silently fails (no "doing it wrong" message) and the following register has no impact. Scripts can therefore be enqueued and dequeued (by "handle") before they are registered.

Fixes #54529.


git-svn-id: https://develop.svn.wordpress.org/trunk@52338 602fd350-edb4-49c9-b593-d223f7449a82

src/wp-includes/class.wp-dependencies.php

@@ -94,6 +94,15 @@ class WP_Dependencies {
 	 */
 	private $all_queued_deps;
 
+	/**
+	 * List of assets enqueued before details were registered.
+	 *
+	 * @since 5.9.0
+	 *
+	 * @var array
+	 */
+	private $queued_before_register = array();
+
 	/**
 	 * Processes the items and dependencies.
 	 *
@@ -248,6 +257,18 @@ public function add( $handle, $src, $deps = array(), $ver = false, $args = null
 			return false;
 		}
 		$this->registered[ $handle ] = new _WP_Dependency( $handle, $src, $deps, $ver, $args );
+
+		// If the item was enqueued before the details were registered, enqueue it now.
+		if ( array_key_exists( $handle, $this->queued_before_register ) ) {
+			if ( ! is_null( $this->queued_before_register[ $handle ] ) ) {
+				$this->enqueue( $handle . '?' . $this->queued_before_register[ $handle ] );
+			} else {
+				$this->enqueue( $handle );
+			}
+
+			unset( $this->queued_before_register[ $handle ] );
+		}
+
 		return true;
 	}
 
@@ -334,6 +355,12 @@ public function enqueue( $handles ) {
 				if ( isset( $handle[1] ) ) {
 					$this->args[ $handle[0] ] = $handle[1];
 				}
+			} else if ( ! isset( $this->registered[ $handle[0] ] ) ) {
+				$this->queued_before_register[ $handle[0] ] = null; // $args
+
+				if ( isset( $handle[1] ) ) {
+					$this->queued_before_register[ $handle[0] ] = $handle[1];
+				}
 			}
 		}
 	}
@@ -360,6 +387,8 @@ public function dequeue( $handles ) {
 
 				unset( $this->queue[ $key ] );
 				unset( $this->args[ $handle[0] ] );
+			} else if ( array_key_exists( $handle[0], $this->queued_before_register ) ) {
+				unset( $this->queued_before_register[ $handle[0] ] );
 			}
 		}
 	}

tests/phpunit/tests/dependencies.php

@@ -136,4 +136,18 @@ public function test_query_and_registered_enqueued() {
 		$this->assertFalse( $dep->query( 'one' ) );
 
 	}
+
+	function test_enqueue_before_register() {
+		$dep = new WP_Dependencies;
+
+		$this->assertArrayNotHasKey( 'one', $dep->registered );
+
+		$dep->enqueue( 'one' );
+
+		$this->assertNotContains( 'one', $dep->queue );
+
+		$this->assertTrue( $dep->add( 'one', '' ) );
+
+		$this->assertContains( 'one', $dep->queue );
+	}
 }