includes/resourceloader/ResourceLoaderImageModule.php

   1 <?php
   2 /**
   3  * Resource loader module for generated and embedded images.
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  18  * http://www.gnu.org/copyleft/gpl.html
  19  *
  20  * @file
  21  * @author Trevor Parscal
  22  */
  23
  24 /**
  25  * Resource loader module for generated and embedded images.
  26  *
  27  * @since 1.25
  28  */
  29 class ResourceLoaderImageModule extends ResourceLoaderModule {
  30
  31         private $definition = null;
  32
  33         /**
  34          * Local base path, see __construct()
  35          * @var string
  36          */
  37         protected $localBasePath = '';
  38
  39         protected $origin = self::ORIGIN_CORE_SITEWIDE;
  40
  41         protected $images = array();
  42         protected $variants = array();
  43         protected $prefix = null;
  44         protected $selectorWithoutVariant = '.{prefix}-{name}';
  45         protected $selectorWithVariant = '.{prefix}-{name}-{variant}';
  46         protected $targets = array( 'desktop', 'mobile' );
  47
  48         /** @var string Position on the page to load this module at */
  49         protected $position = 'bottom';
  50
  51         /**
  52          * Constructs a new module from an options array.
  53          *
  54          * @param array $options List of options; if not given or empty, an empty module will be
  55          *     constructed
  56          * @param string $localBasePath Base path to prepend to all local paths in $options. Defaults
  57          *     to $IP
  58          *
  59          * Below is a description for the $options array:
  60          * @par Construction options:
  61          * @code
  62          *     array(
  63          *         // Base path to prepend to all local paths in $options. Defaults to $IP
  64          *         'localBasePath' => [base path],
  65          *         // Path to JSON file that contains any of the settings below
  66          *         'data' => [file path string]
  67          *         // CSS class prefix to use in all style rules
  68          *         'prefix' => [CSS class prefix],
  69          *         // Alternatively: Format of CSS selector to use in all style rules
  70          *         'selector' => [CSS selector template, variables: {prefix} {name} {variant}],
  71          *         // Alternatively: When using variants
  72          *         'selectorWithoutVariant' => [CSS selector template, variables: {prefix} {name}],
  73          *         'selectorWithVariant' => [CSS selector template, variables: {prefix} {name} {variant}],
  74          *         // List of variants that may be used for the image files
  75          *         'variants' => array(
  76          *                 [variant name] => array(
  77          *                     'color' => [color string, e.g. '#ffff00'],
  78          *                     'global' => [boolean, if true, this variant is available
  79          *                                  for all images of this type],
  80          *                 ),
  81          *             ...
  82          *         ),
  83          *         // List of image files and their options
  84          *         'images' => array(
  85          *                 [file path string],
  86          *                 [file path string] => array(
  87          *                     'name' => [image name string, defaults to file name],
  88          *                     'variants' => [array of variant name strings, variants
  89          *                                    available for this image],
  90          *                 ),
  91          *             ...
  92          *         ),
  93          *     )
  94          * @endcode
  95          * @throws InvalidArgumentException
  96          */
  97         public function __construct( $options = array(), $localBasePath = null ) {
  98                 $this->localBasePath = self::extractLocalBasePath( $options, $localBasePath );
  99
 100                 $this->definition = $options;
 101         }
 102
 103         /**
 104          * Parse definition and external JSON data, if referenced.
 105          */
 106         private function loadFromDefinition() {
 107                 if ( $this->definition === null ) {
 108                         return;
 109                 }
 110
 111                 $options = $this->definition;
 112                 $this->definition = null;
 113
 114                 if ( isset( $options['data'] ) ) {
 115                         $dataPath = $this->localBasePath . '/' . $options['data'];
 116                         $data = json_decode( file_get_contents( $dataPath ), true );
 117                         $options = array_merge( $data, $options );
 118                 }
 119
 120                 // Accepted combinations:
 121                 // * prefix
 122                 // * selector
 123                 // * selectorWithoutVariant + selectorWithVariant
 124                 // * prefix + selector
 125                 // * prefix + selectorWithoutVariant + selectorWithVariant
 126
 127                 $prefix = isset( $options['prefix'] ) && $options['prefix'];
 128                 $selector = isset( $options['selector'] ) && $options['selector'];
 129                 $selectorWithoutVariant = isset( $options['selectorWithoutVariant'] ) && $options['selectorWithoutVariant'];
 130                 $selectorWithVariant = isset( $options['selectorWithVariant'] ) && $options['selectorWithVariant'];
 131
 132                 if ( $selectorWithoutVariant && !$selectorWithVariant ) {
 133                         throw new InvalidArgumentException( "Given 'selectorWithoutVariant' but no 'selectorWithVariant'." );
 134                 }
 135                 if ( $selectorWithVariant && !$selectorWithoutVariant ) {
 136                         throw new InvalidArgumentException( "Given 'selectorWithVariant' but no 'selectorWithoutVariant'." );
 137                 }
 138                 if ( $selector && $selectorWithVariant ) {
 139                         throw new InvalidArgumentException( "Incompatible 'selector' and 'selectorWithVariant'+'selectorWithoutVariant' given." );
 140                 }
 141                 if ( !$prefix && !$selector && !$selectorWithVariant ) {
 142                         throw new InvalidArgumentException( "None of 'prefix', 'selector' or 'selectorWithVariant'+'selectorWithoutVariant' given." );
 143                 }
 144
 145                 foreach ( $options as $member => $option ) {
 146                         switch ( $member ) {
 147                                 case 'images':
 148                                 case 'variants':
 149                                         if ( !is_array( $option ) ) {
 150                                                 throw new InvalidArgumentException(
 151                                                         "Invalid list error. '$option' given, array expected."
 152                                                 );
 153                                         }
 154                                         $this->{$member} = $option;
 155                                         break;
 156
 157                                 case 'position':
 158                                         $this->isPositionDefined = true;
 159                                 case 'prefix':
 160                                 case 'selectorWithoutVariant':
 161                                 case 'selectorWithVariant':
 162                                         $this->{$member} = (string)$option;
 163                                         break;
 164
 165                                 case 'selector':
 166                                         $this->selectorWithoutVariant = $this->selectorWithVariant = (string)$option;
 167                         }
 168                 }
 169         }
 170
 171         /**
 172          * Get CSS class prefix used by this module.
 173          * @return string
 174          */
 175         public function getPrefix() {
 176                 $this->loadFromDefinition();
 177                 return $this->prefix;
 178         }
 179
 180         /**
 181          * Get CSS selector templates used by this module.
 182          * @return string
 183          */
 184         public function getSelectors() {
 185                 $this->loadFromDefinition();
 186                 return array(
 187                         'selectorWithoutVariant' => $this->selectorWithoutVariant,
 188                         'selectorWithVariant' => $this->selectorWithVariant,
 189                 );
 190         }
 191
 192         /**
 193          * Get a ResourceLoaderImage object for given image.
 194          * @param string $name Image name
 195          * @return ResourceLoaderImage|null
 196          */
 197         public function getImage( $name ) {
 198                 $this->loadFromDefinition();
 199                 $images = $this->getImages();
 200                 return isset( $images[$name] ) ? $images[$name] : null;
 201         }
 202
 203         /**
 204          * Get ResourceLoaderImage objects for all images.
 205          * @return ResourceLoaderImage[] Array keyed by image name
 206          */
 207         public function getImages() {
 208                 if ( !isset( $this->imageObjects ) ) {
 209                         $this->loadFromDefinition();
 210                         $this->imageObjects = array();
 211
 212                         foreach ( $this->images as $name => $options ) {
 213                                 $fileDescriptor = is_string( $options ) ? $options : $options['file'];
 214
 215                                 $allowedVariants = array_merge(
 216                                         is_array( $options ) && isset( $options['variants'] ) ? $options['variants'] : array(),
 217                                         $this->getGlobalVariants()
 218                                 );
 219                                 if ( isset( $this->variants ) ) {
 220                                         $variantConfig = array_intersect_key(
 221                                                 $this->variants,
 222                                                 array_fill_keys( $allowedVariants, true )
 223                                         );
 224                                 } else {
 225                                         $variantConfig = array();
 226                                 }
 227
 228                                 $image = new ResourceLoaderImage(
 229                                         $name,
 230                                         $this->getName(),
 231                                         $fileDescriptor,
 232                                         $this->localBasePath,
 233                                         $variantConfig
 234                                 );
 235                                 $this->imageObjects[ $image->getName() ] = $image;
 236                         }
 237                 }
 238
 239                 return $this->imageObjects;
 240         }
 241
 242         /**
 243          * Get list of variants in this module that are 'global', i.e., available
 244          * for every image regardless of image options.
 245          * @return string[]
 246          */
 247         public function getGlobalVariants() {
 248                 if ( !isset( $this->globalVariants ) ) {
 249                         $this->loadFromDefinition();
 250                         $this->globalVariants = array();
 251
 252                         if ( isset( $this->variants ) ) {
 253                                 foreach ( $this->variants as $name => $config ) {
 254                                         if ( isset( $config['global'] ) && $config['global'] ) {
 255                                                 $this->globalVariants[] = $name;
 256                                         }
 257                                 }
 258                         }
 259                 }
 260
 261                 return $this->globalVariants;
 262         }
 263
 264         /**
 265          * @param ResourceLoaderContext $context
 266          * @return array
 267          */
 268         public function getStyles( ResourceLoaderContext $context ) {
 269                 $this->loadFromDefinition();
 270
 271                 // Build CSS rules
 272                 $rules = array();
 273                 $script = $context->getResourceLoader()->getLoadScript( $this->getSource() );
 274                 $selectors = $this->getSelectors();
 275
 276                 foreach ( $this->getImages() as $name => $image ) {
 277                         $declarations = $this->getCssDeclarations(
 278                                 $image->getDataUri( $context, null, 'original' ),
 279                                 $image->getUrl( $context, $script, null, 'rasterized' )
 280                         );
 281                         $declarations = implode( "\n\t", $declarations );
 282                         $selector = strtr(
 283                                 $selectors['selectorWithoutVariant'],
 284                                 array(
 285                                         '{prefix}' => $this->getPrefix(),
 286                                         '{name}' => $name,
 287                                         '{variant}' => '',
 288                                 )
 289                         );
 290                         $rules[] = "$selector {\n\t$declarations\n}";
 291
 292                         foreach ( $image->getVariants() as $variant ) {
 293                                 $declarations = $this->getCssDeclarations(
 294                                         $image->getDataUri( $context, $variant, 'original' ),
 295                                         $image->getUrl( $context, $script, $variant, 'rasterized' )
 296                                 );
 297                                 $declarations = implode( "\n\t", $declarations );
 298                                 $selector = strtr(
 299                                         $selectors['selectorWithVariant'],
 300                                         array(
 301                                                 '{prefix}' => $this->getPrefix(),
 302                                                 '{name}' => $name,
 303                                                 '{variant}' => $variant,
 304                                         )
 305                                 );
 306                                 $rules[] = "$selector {\n\t$declarations\n}";
 307                         }
 308                 }
 309
 310                 $style = implode( "\n", $rules );
 311                 return array( 'all' => $style );
 312         }
 313
 314         /**
 315          * SVG support using a transparent gradient to guarantee cross-browser
 316          * compatibility (browsers able to understand gradient syntax support also SVG).
 317          * http://pauginer.tumblr.com/post/36614680636/invisible-gradient-technique
 318          *
 319          * Keep synchronized with the .background-image-svg LESS mixin in
 320          * /resources/src/mediawiki.less/mediawiki.mixins.less.
 321          *
 322          * @param string $primary Primary URI
 323          * @param string $fallback Fallback URI
 324          * @return string[] CSS declarations to use given URIs as background-image
 325          */
 326         protected function getCssDeclarations( $primary, $fallback ) {
 327                 return array(
 328                         "background-image: url($fallback);",
 329                         "background-image: -webkit-linear-gradient(transparent, transparent), url($primary);",
 330                         "background-image: linear-gradient(transparent, transparent), url($primary);",
 331                         "background-image: -o-linear-gradient(transparent, transparent), url($fallback);",
 332                 );
 333         }
 334
 335         /**
 336          * @return bool
 337          */
 338         public function supportsURLLoading() {
 339                 return false;
 340         }
 341
 342         /**
 343          * Get the definition summary for this module.
 344          *
 345          * @param ResourceLoaderContext $context
 346          * @return array
 347          */
 348         public function getDefinitionSummary( ResourceLoaderContext $context ) {
 349                 $this->loadFromDefinition();
 350                 $summary = parent::getDefinitionSummary( $context );
 351                 foreach ( array(
 352                         'localBasePath',
 353                         'images',
 354                         'variants',
 355                         'prefix',
 356                         'selectorWithoutVariant',
 357                         'selectorWithVariant',
 358                 ) as $member ) {
 359                         $summary[$member] = $this->{$member};
 360                 };
 361                 return $summary;
 362         }
 363
 364         /**
 365          * Get the last modified timestamp of this module.
 366          *
 367          * @param ResourceLoaderContext $context Context in which to calculate
 368          *     the modified time
 369          * @return int UNIX timestamp
 370          */
 371         public function getModifiedTime( ResourceLoaderContext $context ) {
 372                 $this->loadFromDefinition();
 373                 $files = array();
 374                 foreach ( $this->getImages() as $name => $image ) {
 375                         $files[] = $image->getPath( $context );
 376                 }
 377
 378                 $files = array_values( array_unique( $files ) );
 379                 $filesMtime = max( array_map( array( __CLASS__, 'safeFilemtime' ), $files ) );
 380
 381                 return max(
 382                         $filesMtime,
 383                         $this->getDefinitionMtime( $context )
 384                 );
 385         }
 386
 387         /**
 388          * Extract a local base path from module definition information.
 389          *
 390          * @param array $options Module definition
 391          * @param string $localBasePath Path to use if not provided in module definition. Defaults
 392          *     to $IP
 393          * @return string Local base path
 394          */
 395         public static function extractLocalBasePath( $options, $localBasePath = null ) {
 396                 global $IP;
 397
 398                 if ( $localBasePath === null ) {
 399                         $localBasePath = $IP;
 400                 }
 401
 402                 if ( array_key_exists( 'localBasePath', $options ) ) {
 403                         $localBasePath = (string)$options['localBasePath'];
 404                 }
 405
 406                 return $localBasePath;
 407         }
 408
 409         /**
 410          * @return string
 411          */
 412         public function getPosition() {
 413                 $this->loadFromDefinition();
 414                 return $this->position;
 415         }
 416
 417         public function isPositionDefault() {
 418                 $this->loadFromDefinition();
 419                 return parent::isPositionDefault();
 420         }
 421 }