Changeset 48272

Timestamp:

07/02/2020 02:01:28 AM (4 years ago)

Author:

flixos90

Message:

Media: Improve support for opting out of lazy-loading for template images.

With this changeset, in addition to the already present wp_lazy_loading_enabled filter, developers can now opt out of lazy-loading template images via wp_get_attachment_image() by passing a loading attribute with boolean value false. This can be used e.g. by theme developers on images which are very likely to be in the initial viewport.

This changeset also improves related test coverage.

Props adamsilverstein, azaozz, joemcgill, johnbillion.
See #50425, #44427.

Location:

trunk

Files:

• src/wp-includes/media.php (modified) (2 diffs)
• tests/phpunit/tests/media.php (modified) (3 diffs)

trunk/src/wp-includes/media.php

@@ -1049 +1049 @@
         $attr = wp_parse_args( $attr, $default_attr );
 
+        // If `loading` attribute default of `lazy` is overridden for this
+        // image to omit the attribute, ensure it is not included.
+        if ( array_key_exists( 'loading', $attr ) && ! $attr['loading'] ) {
+            unset( $attr['loading'] );
+        }
+
         // Generate 'srcset' and 'sizes' if not already present.
         if ( empty( $attr['srcset'] ) ) {
@@ -1726 +1732 @@
      * @since 5.5.0
      *
-     * @param string $value   The `loading` attribute value, defaults to `lazy`.
-     * @param string $image   The HTML `img` tag to be filtered.
-     * @param string $context Additional context about how the function was called or where the img tag is.
+     * @param string|bool $value   The `loading` attribute value. Returning a false-y value will result in the
+     *                             attribute being omitted for the image. Default is `lazy`.
+     * @param string      $image   The HTML `img` tag to be filtered.
+     * @param string      $context Additional context about how the function was called or where the img tag is.
      */
     $value = apply_filters( 'wp_img_tag_add_loading_attr', 'lazy', $image, $context );

trunk/tests/phpunit/tests/media.php

@@ -2676 +2676 @@
 
     /**
+     * @ticket 44427
+     * @ticket 50367
+     */
+    function test_wp_img_tag_add_loading_attr() {
+        $img = '<img src="example.png" alt=" width="300" height="225" />';
+        $img = wp_img_tag_add_loading_attr( $img, 'test' );
+
+        $this->assertContains( ' loading="lazy"', $img );
+    }
+
+    /**
+     * @ticket 44427
      * @ticket 50367
      */
@@ -2682 +2694 @@
         $img = wp_img_tag_add_loading_attr( $img, 'test' );
 
-        $this->assertNotContains( ' loading="lazy"', $img );
-    }
-
-    /**
+        $this->assertNotContains( ' loading=', $img );
+    }
+
+    /**
+     * @ticket 44427
      * @ticket 50367
      */
@@ -2692 +2705 @@
         $img = wp_img_tag_add_loading_attr( $img, 'test' );
 
+        $this->assertNotContains( ' loading=', $img );
+
+        // Test specifically that the attribute is not there with double-quotes,
+        // to avoid regressions.
         $this->assertNotContains( ' loading="lazy"', $img );
+    }
+
+    /**
+     * @ticket 44427
+     * @ticket 50425
+     */
+    function test_wp_img_tag_add_loading_attr_opt_out() {
+        $img = '<img src="example.png" alt=" width="300" height="225" />';
+        add_filter( 'wp_img_tag_add_loading_attr', '__return_false' );
+
+        $this->assertNotContains( ' loading=', $img );
+    }
+
+    /**
+     * @ticket 44427
+     * @ticket 50425
+     */
+    function test_wp_get_attachment_image_loading() {
+        $img = wp_get_attachment_image( self::$large_id );
+
+        $this->assertContains( ' loading="lazy"', $img );
+    }
+
+    /**
+     * @ticket 44427
+     * @ticket 50425
+     */
+    function test_wp_get_attachment_image_loading_opt_out() {
+        add_filter( 'wp_lazy_loading_enabled', '__return_false' );
+        $img = wp_get_attachment_image( self::$large_id );
+
+        // There should not be any loading attribute in this case.
+        $this->assertNotContains( ' loading=', $img );
+    }
+
+    /**
+     * @ticket 44427
+     * @ticket 50425
+     */
+    function test_wp_get_attachment_image_loading_opt_out_individual() {
+        // The default is already tested above, the filter below ensures that
+        // lazy-loading is definitely enabled globally for images.
+        add_filter( 'wp_lazy_loading_enabled', '__return_true' );
+
+        $img = wp_get_attachment_image( self::$large_id, 'thumbnail', false, array( 'loading' => false ) );
+
+        // There should not be any loading attribute in this case.
+        $this->assertNotContains( ' loading=', $img );
+    }
+
+    /**
+     * @ticket 44427
+     * @ticket 50425
+     * @dataProvider data_wp_lazy_loading_enabled_tag_name_defaults
+     *
+     * @param string $tag_name  Function context.
+     * @param bool   $expected Expected return value.
+     */
+    function test_wp_lazy_loading_enabled_tag_name_defaults( $tag_name, $expected ) {
+        if ( $expected ) {
+            $this->assertTrue( wp_lazy_loading_enabled( $tag_name, 'the_content' ) );
+        } else {
+            $this->assertFalse( wp_lazy_loading_enabled( $tag_name, 'the_content' ) );
+        }
+    }
+
+    function data_wp_lazy_loading_enabled_tag_name_defaults() {
+        return array(
+            'img => true'            => array( 'img', true ),
+            'iframe => false'        => array( 'iframe', false ),
+            'arbitrary tag => false' => array( 'blink', false ),
+        );
+    }
+
+    /**
+     * @ticket 50425
+     * @dataProvider data_wp_lazy_loading_enabled_context_defaults
+     *
+     * @param string $context  Function context.
+     * @param bool   $expected Expected return value.
+     */
+    function test_wp_lazy_loading_enabled_context_defaults( $context, $expected ) {
+        if ( $expected ) {
+            $this->assertTrue( wp_lazy_loading_enabled( 'img', $context ) );
+        } else {
+            $this->assertFalse( wp_lazy_loading_enabled( 'img', $context ) );
+        }
+    }
+
+    function data_wp_lazy_loading_enabled_context_defaults() {
+        return array(
+            'wp_get_attachment_image => true' => array( 'wp_get_attachment_image', true ),
+            'the_content => true'             => array( 'the_content', true ),
+            'the_excerpt => true'             => array( 'the_excerpt', true ),
+            'widget_text_content => true'     => array( 'widget_text_content', true ),
+            'get_avatar => true'              => array( 'get_avatar', true ),
+            'arbitrary context => true'       => array( 'something_completely_arbitrary', true ),
+        );
     }
 }