Implement SSR for amp-audio

src/Optimizer/Error/CannotRemoveBoilerplate.php

@@ -22,8 +22,6 @@ final class CannotRemoveBoilerplate implements Error
                                           . 'attribute produced an error: ';
     const RENDER_DELAYING_SCRIPT_STRING = 'Cannot remove boilerplate because the document contains a render-delaying '
                                           . 'extension: ';
-    const AMP_AUDIO_STRING              = 'Cannot remove boilerplate because the document contains an extension that '
-                                          . 'needs to know the dimensions of the browser: ';
     const UNSUPPORTED_LAYOUT_STRING     = 'Cannot remove boilerplate because of an unsupported layout: ';
 
     /**
@@ -59,17 +57,6 @@ public static function fromAmpExperiment(Element $element)
         return new self(self::RENDER_DELAYING_SCRIPT_STRING . $element->tagName);
     }
 
-    /**
-     * Instantiate a CannotRemoveBoilerplate object for an amp-audio element.
-     *
-     * @param Element $element amp-audio element.
-     * @return self
-     */
-    public static function fromAmpAudio(Element $element)
-    {
-        return new self(self::AMP_AUDIO_STRING . new ElementDump($element));
-    }
-
     /**
      * Instantiate a CannotRemoveBoilerplate object for an element with an unsupported layout.
      *

src/Optimizer/Transformer/ServerSideRendering.php

@@ -127,20 +127,18 @@ public function transform(Document $document, ErrorCollection $errors)
             }
 
             /*
-             * amp-experiment is a render delaying extension iff the tag is used in the doc. We check for that here
-             * rather than checking for the existence of the amp-experiment script in IsRenderDelayingExtension below.
+             * Server-side rendering of an amp-audio element.
              */
-            if ($ampElement->tagName === Extension::EXPERIMENT && $this->isAmpExperimentUsed($ampElement)) {
-                $errors->add(Error\CannotRemoveBoilerplate::fromAmpExperiment($ampElement));
-                $canRemoveBoilerplate = false;
+            if ($ampElement->tagName === Extension::AUDIO) {
+                $this->ssrAmpAudio($document, $ampElement);
             }
 
             /*
-             * amp-audio requires knowing the dimensions of the browser. Do not remove the boilerplate or apply layout
-             * if amp-audio is present in the document.
+             * amp-experiment is a render delaying extension iff the tag is used in the doc. We check for that here
+             * rather than checking for the existence of the amp-experiment script in IsRenderDelayingExtension below.
              */
-            if ($ampElement->tagName === Extension::AUDIO) {
-                $errors->add(Error\CannotRemoveBoilerplate::fromAmpAudio($ampElement));
+            if ($ampElement->tagName === Extension::EXPERIMENT && $this->isAmpExperimentUsed($ampElement)) {
+                $errors->add(Error\CannotRemoveBoilerplate::fromAmpExperiment($ampElement));
                 $canRemoveBoilerplate = false;
             }
 
@@ -1060,4 +1058,28 @@ private function isZero($number)
 
         return abs($number) < self::FLOATING_POINT_EPSILON;
     }
+
+    /**
+     * Server-side rendering of an amp-audio element.
+     *
+     * @param Document $document DOM document to apply the transformations to.
+     * @param Element  $element  Element to adapt.
+     */
+    private function ssrAmpAudio(Document $document, Element $element)
+    {
+        // Check if we already have a SSR-ed audio element.
+        if ($element->hasChildNodes()) {
+            foreach ($element->childNodes as $childNode) {
+                if ($childNode instanceof Element && $childNode->tagName === Tag::AUDIO) {
+                    return;
+                }
+            }
+        }
+
+        $audio    = $document->createElement(Tag::AUDIO);
+        $controls = $document->createAttribute(Attribute::CONTROLS);
+
+        $audio->setAttributeNode($controls);
+        $element->appendChild($audio);
+    }
 }

tests/Optimizer/SpecTest.php

@@ -48,6 +48,8 @@ final class SpecTest extends TestCase
         'ReorderHead - preserves_amp_custom_style_order' => 'see https://github.com/ampproject/amp-toolbox/issues/604',
 
         'MinifyHtml - minifies_inline_amp-script'          => 'see https://github.com/ampproject/amp-toolbox-php/issues/260',
+
+        'ServerSideRendering - does_not_transform_amp_audio' => 'The amp-toolbox needs to implement SSR amp-audio',
     ];
 
     const CLASS_SKIP_TEST = '__SKIP__';

tests/Optimizer/Transformer/ServerSideRenderingTest.php

@@ -132,14 +132,7 @@ public function dataTransform()
 
             'amp-audio' => [
                 $input('<amp-audio></amp-audio>'),
-                $expectWithBoilerplate('<amp-audio></amp-audio>'),
-                [
-                    Error\CannotRemoveBoilerplate::fromAmpAudio(
-                        Document::fromHtmlFragment(
-                            '<amp-audio></amp-audio>'
-                        )->body->firstChild
-                    ),
-                ],
+                $expectWithoutBoilerplate('<amp-audio><audio controls></audio></amp-audio>'),
             ],
 
             'amp-experiment is non-empty' => [
@@ -326,6 +319,40 @@ public function dataTransform()
                 $input('<amp-ad type="doubleclick" data-slot="/6355419/Travel" layout="fluid" height="fluid" width="300"></amp-ad>'),
                 $expectWithoutBoilerplate('<amp-ad class="i-amphtml-layout-fluid i-amphtml-layout-awaiting-size" data-slot="/6355419/Travel" height="fluid" width="300" i-amphtml-layout="fluid" layout="fluid" style="width:100%;height:0;" type="doubleclick"></amp-ad>'),
             ],
+
+            'server side render amp-audio' => [
+                $input('<amp-audio src="http://example.com/audio.mp3" width="300"></amp-audio>'),
+                $expectWithoutBoilerplate('<amp-audio src="http://example.com/audio.mp3" width="300"><audio controls></audio></amp-audio>'),
+            ],
+
+            'ssr amp-audio appends audio element' => [
+                $input(
+                    '<amp-audio src="http://example.com/audio.mp3" width="300">'
+                        . '<div fallback="">Your browser doesn’t support HTML5 audio</div>'
+                    . '</amp-audio>'
+                ),
+                $expectWithoutBoilerplate(
+                    '<amp-audio src="http://example.com/audio.mp3" width="300">'
+                        . '<div fallback="">Your browser doesn’t support HTML5 audio</div>'
+                        . '<audio controls></audio>'
+                    . '</amp-audio>'
+                ),
+            ],
+
+            'skip ssr amp-audio if audio child node is present' => [
+                $input(
+                    '<amp-audio src="http://example.com/audio.mp3" width="300">'
+                        . '<div fallback="">Your browser doesn’t support HTML5 audio</div>'
+                        . '<audio controls src="http://example.com/audio.mp3"></audio>'
+                    . '</amp-audio>'
+                ),
+                $expectWithoutBoilerplate(
+                    '<amp-audio src="http://example.com/audio.mp3" width="300">'
+                        . '<div fallback="">Your browser doesn’t support HTML5 audio</div>'
+                        . '<audio controls src="http://example.com/audio.mp3"></audio>'
+                    . '</amp-audio>'
+                ),
+            ]
         ];
     }