FormatMetadata::fetchExtendedMetadata: Ignore multiple EXIF/XMP values

Ignore all but the first value of multivalued metadata fields. Before
this, the function returned an array of values for such fields,
causing various errors.

Bug: 72652
Change-Id: I0fd22b78e4938eecc506d870e352b3b196ee3ace
Mingle: https://wikimedia.mingle.thoughtworks.com/projects/multimedia/cards/973

diff --git a/includes/media/FormatMetadata.php b/includes/media/FormatMetadata.php
index 4356953..07d7618 100644 (file)
--- a/includes/media/FormatMetadata.php
+++ b/includes/media/FormatMetadata.php
@@ -1624,6 +1624,7 @@ class FormatMetadata extends ContextSource {
                        if ( $this->singleLang ) {
                                $this->resolveMultilangMetadata( $extendedMetadata );
                        }
+                       $this->discardMultipleValues( $extendedMetadata );
                        // Make sure the metadata won't break the API when an XML format is used.
                        // This is an API-specific function so it would be cleaner to call it from
                        // outside fetchExtendedMetadata, but this way we don't need to redo the
@@ -1776,6 +1777,32 @@ class FormatMetadata extends ContextSource {
                return null;
        }
 
+       /**
+        * Turns an XMP-style multivalue array into a single value by dropping all but the first value.
+        * If the value is not a multivalue array (or a multivalue array inside a multilang array), it is returned unchanged.
+        * See mediawiki.org/wiki/Manual:File_metadata_handling#Multi-language_array_format
+        * @param mixed $value
+        * @return mixed The value, or the first value if there were multiple ones
+        * @since 1.25
+        */
+       protected function resolveMultivalueValue( $value ) {
+               if ( !is_array( $value ) ) {
+                       return $value;
+               } elseif ( isset( $value['_type'] ) && $value['_type'] === 'lang' ) { // if this is a multilang array, process fields separately
+                       $newValue = array();
+                       foreach ( $value as $k => $v ) {
+                               $newValue[$k] = $this->resolveMultivalueValue( $v );
+                       }
+                       return $newValue;
+               } else { // _type is 'ul' or 'ol' or missing in which case it defaults to 'ul'
+                       list( $k, $v ) = each( $value );
+                       if ( $k === '_type' ) {
+                               $v = current( $value );
+                       }
+                       return $v;
+               }
+       }
+
        /**
         * Takes an array returned by the getExtendedMetadata* functions,
         * and resolves multi-language values in it.
@@ -1793,6 +1820,29 @@ class FormatMetadata extends ContextSource {
                }
        }
 
+       /**
+        * Takes an array returned by the getExtendedMetadata* functions,
+        * and turns all fields into single-valued ones by dropping extra values.
+        * @param array $metadata
+        * @since 1.25
+        */
+       protected function discardMultipleValues( &$metadata ) {
+               if ( !is_array( $metadata ) ) {
+                       return;
+               }
+               foreach ( $metadata as $key => &$field ) {
+                       if ( $key === 'Software' || $key === 'Contact' ) {
+                               // we skip some fields which have composite values. They are not particularly interesting
+                               // and you can get them via the metadata / commonmetadata APIs anyway.
+                               continue;
+                       }
+                       if ( isset( $field['value'] ) ) {
+                               $field['value'] = $this->resolveMultivalueValue( $field['value'] );
+                       }
+               }
+
+       }
+
        /**
         * Makes sure the given array is a valid API response fragment
         * (can be transformed into XML)

diff --git a/tests/phpunit/includes/media/FormatMetadataTest.php b/tests/phpunit/includes/media/FormatMetadataTest.php
index 002e2cb..97aa0a3 100644 (file)
--- a/tests/phpunit/includes/media/FormatMetadataTest.php
+++ b/tests/phpunit/includes/media/FormatMetadataTest.php
@@ -68,4 +68,36 @@ class FormatMetadataTest extends MediaWikiMediaTestCase {
                        // TODO: more test cases
                );
        }
+
+       /**
+        * @param mixed $input
+        * @param mixed $output
+        * @dataProvider provideResolveMultivalueValue
+        * @covers FormatMetadata::resolveMultivalueValue
+        */
+       public function testResolveMultivalueValue( $input, $output ) {
+               $formatMetadata = new FormatMetadata();
+               $class = new ReflectionClass( 'FormatMetadata' );
+               $method = $class->getMethod( 'resolveMultivalueValue' );
+               $method->setAccessible( true );
+               $actualInput = $method->invoke( $formatMetadata, $input );
+               $this->assertEquals( $output, $actualInput );
+       }
+
+       public function provideResolveMultivalueValue() {
+               return array(
+                       'nonArray' => array( 'foo', 'foo' ),
+                       'multiValue' => array( array( 'first', 'second', 'third', '_type' => 'ol' ), 'first' ),
+                       'noType' => array( array( 'first', 'second', 'third' ), 'first' ),
+                       'typeFirst' => array( array( '_type' => 'ol', 'first', 'second', 'third' ), 'first' ),
+                   'multilang' => array(
+                           array( 'en' => 'first', 'de' => 'Erste', '_type' => 'lang' ),
+                           array( 'en' => 'first', 'de' => 'Erste', '_type' => 'lang' ),
+                   ),
+                   'multilang-multivalue' => array(
+                           array( 'en' => array( 'first', 'second' ), 'de' => array( 'Erste', 'Zweite' ), '_type' => 'lang' ),
+                           array( 'en' => 'first', 'de' => 'Erste', '_type' => 'lang' ),
+                   ),
+               );
+       }
 }