Html::srcSet: allow density to be specified either with or without trailing 'x'

$wgLogoHD is meant to contain high-density alternatives for $wgLogo, but its
keys include the trailing 'x' (e.g., '1.5x'), making it unusable with
Html::srcSet(). Fix that by normalizing all density values to have a
single trailing 'x'.

Change-Id: I62cc3a9e4aeff3a7cb102de2965b8b40fd106c37

diff --git a/includes/Html.php b/includes/Html.php
index effc488..d312e0a 100644 (file)
--- a/includes/Html.php
+++ b/includes/Html.php
@@ -1025,9 +1025,24 @@ class Html {
        }
 
        /**
-        * Generate a srcset attribute value from an array mapping pixel densities
-        * to URLs. Note that srcset supports width and height values as well, which
-        * are not used here.
+        * Generate a srcset attribute value.
+        *
+        * Generates a srcset attribute value from an array mapping pixel densities
+        * to URLs. A trailing 'x' in pixel density values is optional.
+        *
+        * @note srcset width and height values are not supported.
+        *
+        * @see http://www.whatwg.org/html/embedded-content-1.html#attr-img-srcset
+        *
+        * @par Example:
+        * @code
+        *     Html::srcSet( array(
+        *         '1x'   => 'standard.jpeg',
+        *         '1.5x' => 'large.jpeg',
+        *         '3x'   => 'extra-large.jpeg',
+        *     ) );
+        *     // gives 'standard.jpeg 1x, large.jpeg 1.5x, extra-large.jpeg 2x'
+        * @endcode
         *
         * @param string[] $urls
         * @return string
@@ -1035,9 +1050,8 @@ class Html {
        static function srcSet( $urls ) {
                $candidates = array();
                foreach ( $urls as $density => $url ) {
-                       // Image candidate syntax per current whatwg live spec, 2012-09-23:
-                       // http://www.whatwg.org/html/embedded-content-1.html#attr-img-srcset
-                       $candidates[] = "{$url} {$density}x";
+                       // Cast density to float to strip 'x'.
+                       $candidates[] = $url . ' ' . (float)$density . 'x';
                }
                return implode( ", ", $candidates );
        }

diff --git a/tests/phpunit/includes/HtmlTest.php b/tests/phpunit/includes/HtmlTest.php
index 0b58536..c5797c4 100644 (file)
--- a/tests/phpunit/includes/HtmlTest.php
+++ b/tests/phpunit/includes/HtmlTest.php
@@ -764,6 +764,30 @@ class HtmlTest extends MediaWikiTestCase {
                        'Label wrapper'
                );
        }
+
+       public static function provideSrcSetImages() {
+               return array(
+                       array( array(), '', 'when there are no images, return empty string' ),
+                       array(
+                               array( '1x' => '1x.png', '1.5x' => '1_5x.png', '2x' => '2x.png' ),
+                               '1x.png 1x, 1_5x.png 1.5x, 2x.png 2x',
+                               'pixel depth keys may include a trailing "x"'
+                       ),
+                       array(
+                               array( '1'  => '1x.png', '1.5' => '1_5x.png', '2'  => '2x.png' ),
+                               '1x.png 1x, 1_5x.png 1.5x, 2x.png 2x',
+                               'pixel depth keys may omit a trailing "x"'
+                       ),
+               );
+       }
+
+       /**
+        * @dataProvider provideSrcSetImages
+        * @covers Html::srcSet
+        */
+       public function testSrcSet( $images, $expected, $message ) {
+               $this->assertEquals( Html::srcSet( $images ), $expected, $message );
+       }
 }
 
 class HtmlTestValue {