Issue #2420751 by Wim Leers, mondrake, attiks:...

Issue #2420751 by Wim Leers, mondrake, attiks: ImageEffectBase::transformDimensions() should have a sane default implementation

core/modules/image/src/ImageEffectBase.php

@@ -71,7 +71,9 @@ public static function create(ContainerInterface $container, array $configuratio
    * {@inheritdoc}
    */
   public function transformDimensions(array &$dimensions) {
-    $dimensions['width'] = $dimensions['height'] = NULL;
+    // Most image effects will not change the dimensions. This base
+    // implementation represents this behavior. Override this method if your
+    // image effect does change the dimensions.
   }
 
   /**

core/modules/image/src/ImageEffectInterface.php

@@ -37,9 +37,12 @@ public function applyEffect(ImageInterface $image);
   /**
    * Determines the dimensions of the styled image.
    *
-   * @param array $dimensions
-   *   Dimensions to be modified - an array with components width and height, in
-   *   pixels.
+   * @param array &$dimensions
+   *   Dimensions to be modified - an array with the following keys:
+   *   - width: the width in pixels, or NULL if unknown
+   *   - height: the height in pixels, or NULL if unknown
+   *   When either of the dimensions are NULL, the corresponding HTML attribute
+   *   will be omitted when an image style using this image effect is used.
    */
   public function transformDimensions(array &$dimensions);
 

core/modules/image/src/Plugin/ImageEffect/ConvertImageEffect.php

@@ -23,12 +23,6 @@
  */
 class ConvertImageEffect extends ConfigurableImageEffectBase {
 
-  /**
-   * {@inheritdoc}
-   */
-  public function transformDimensions(array &$dimensions) {
-  }
-
   /**
    * {@inheritdoc}
    */

core/modules/image/src/Plugin/ImageEffect/DesaturateImageEffect.php

@@ -21,12 +21,6 @@
  */
 class DesaturateImageEffect extends ImageEffectBase {
 
-  /**
-   * {@inheritdoc}
-   */
-  public function transformDimensions(array &$dimensions) {
-  }
-
   /**
    * {@inheritdoc}
    */

core/modules/image/src/Tests/ImageDimensionsTest.php

@@ -221,8 +221,7 @@ function testImageDimensions() {
     $effect_plugin = $style->getEffect($effect_id);
     $style->deleteImageEffect($effect_plugin);
 
-    // Ensure that an effect with no dimensions callback unsets the dimensions.
-    // This ensures compatibility with 7.0 contrib modules.
+    // Ensure that an effect can unset dimensions.
     $effect = array(
       'id' => 'image_module_test_null',
       'data' => array(),

core/modules/image/tests/modules/image_module_test/src/Plugin/ImageEffect/NullTestImageEffect.php

@@ -20,6 +20,14 @@
  */
 class NullTestImageEffect extends ImageEffectBase {
 
+  /**
+   * {@inheritdoc}
+   */
+  public function transformDimensions(array &$dimensions) {
+    // Unset image dimensions.
+    $dimensions['width'] = $dimensions['height'] = NULL;
+  }
+
   /**
    * {@inheritdoc}
    */