resources/src/mediawiki/api/upload.js

   1 /**
   2  * Provides an interface for uploading files to MediaWiki.
   3  *
   4  * @class mw.Api.plugin.upload
   5  * @singleton
   6  */
   7 ( function ( mw, $ ) {
   8         var nonce = 0,
   9                 fieldsAllowed = {
  10                         stash: true,
  11                         filekey: true,
  12                         filename: true,
  13                         comment: true,
  14                         text: true,
  15                         watchlist: true,
  16                         ignorewarnings: true
  17                 };
  18
  19         /**
  20          * @private
  21          * Get nonce for iframe IDs on the page.
  22          *
  23          * @return {number}
  24          */
  25         function getNonce() {
  26                 return nonce++;
  27         }
  28
  29         /**
  30          * @private
  31          * Given a non-empty object, return one of its keys.
  32          *
  33          * @param {Object} obj
  34          * @return {string}
  35          */
  36         function getFirstKey( obj ) {
  37                 for ( var key in obj ) {
  38                         if ( obj.hasOwnProperty( key ) ) {
  39                                 return key;
  40                         }
  41                 }
  42         }
  43
  44         /**
  45          * @private
  46          * Get new iframe object for an upload.
  47          *
  48          * @return {HTMLIframeElement}
  49          */
  50         function getNewIframe( id ) {
  51                 var frame = document.createElement( 'iframe' );
  52                 frame.id = id;
  53                 frame.name = id;
  54                 return frame;
  55         }
  56
  57         /**
  58          * @private
  59          * Shortcut for getting hidden inputs
  60          *
  61          * @return {jQuery}
  62          */
  63         function getHiddenInput( name, val ) {
  64                 return $( '<input type="hidden" />' )
  65                         .attr( 'name', name )
  66                         .val( val );
  67         }
  68
  69         /**
  70          * Process the result of the form submission, returned to an iframe.
  71          * This is the iframe's onload event.
  72          *
  73          * @param {HTMLIframeElement} iframe Iframe to extract result from
  74          * @return {Object} Response from the server. The return value may or may
  75          *   not be an XMLDocument, this code was copied from elsewhere, so if you
  76          *   see an unexpected return type, please file a bug.
  77          */
  78         function processIframeResult( iframe ) {
  79                 var json,
  80                         doc = iframe.contentDocument || frames[ iframe.id ].document;
  81
  82                 if ( doc.XMLDocument ) {
  83                         // The response is a document property in IE
  84                         return doc.XMLDocument;
  85                 }
  86
  87                 if ( doc.body ) {
  88                         // Get the json string
  89                         // We're actually searching through an HTML doc here --
  90                         // according to mdale we need to do this
  91                         // because IE does not load JSON properly in an iframe
  92                         json = $( doc.body ).find( 'pre' ).text();
  93
  94                         return JSON.parse( json );
  95                 }
  96
  97                 // Response is a xml document
  98                 return doc;
  99         }
 100
 101         function formDataAvailable() {
 102                 return window.FormData !== undefined &&
 103                         window.File !== undefined &&
 104                         window.File.prototype.slice !== undefined;
 105         }
 106
 107         $.extend( mw.Api.prototype, {
 108                 /**
 109                  * Upload a file to MediaWiki.
 110                  *
 111                  * The file will be uploaded using AJAX and FormData, if the browser supports it, or via an
 112                  * iframe if it doesn't.
 113                  *
 114                  * Caveats of iframe upload:
 115                  * - The returned jQuery.Promise will not receive `progress` notifications during the upload
 116                  * - It is incompatible with uploads to a foreign wiki using mw.ForeignApi
 117                  * - You must pass a HTMLInputElement and not a File for it to be possible
 118                  *
 119                  * @param {HTMLInputElement|File} file HTML input type=file element with a file already inside
 120                  *  of it, or a File object.
 121                  * @param {Object} data Other upload options, see action=upload API docs for more
 122                  * @return {jQuery.Promise}
 123                  */
 124                 upload: function ( file, data ) {
 125                         var isFileInput, canUseFormData;
 126
 127                         isFileInput = file && file.nodeType === Node.ELEMENT_NODE;
 128
 129                         if ( formDataAvailable() && isFileInput && file.files ) {
 130                                 file = file.files[ 0 ];
 131                         }
 132
 133                         if ( !file ) {
 134                                 throw new Error( 'No file' );
 135                         }
 136
 137                         canUseFormData = formDataAvailable() && file instanceof window.File;
 138
 139                         if ( !isFileInput && !canUseFormData ) {
 140                                 throw new Error( 'Unsupported argument type passed to mw.Api.upload' );
 141                         }
 142
 143                         if ( canUseFormData ) {
 144                                 return this.uploadWithFormData( file, data );
 145                         }
 146
 147                         return this.uploadWithIframe( file, data );
 148                 },
 149
 150                 /**
 151                  * Upload a file to MediaWiki with an iframe and a form.
 152                  *
 153                  * This method is necessary for browsers without the File/FormData
 154                  * APIs, and continues to work in browsers with those APIs.
 155                  *
 156                  * The rough sketch of how this method works is as follows:
 157                  * 1. An iframe is loaded with no content.
 158                  * 2. A form is submitted with the passed-in file input and some extras.
 159                  * 3. The MediaWiki API receives that form data, and sends back a response.
 160                  * 4. The response is sent to the iframe, because we set target=(iframe id)
 161                  * 5. The response is parsed out of the iframe's document, and passed back
 162                  *    through the promise.
 163                  *
 164                  * @private
 165                  * @param {HTMLInputElement} file The file input with a file in it.
 166                  * @param {Object} data Other upload options, see action=upload API docs for more
 167                  * @return {jQuery.Promise}
 168                  */
 169                 uploadWithIframe: function ( file, data ) {
 170                         var key,
 171                                 tokenPromise = $.Deferred(),
 172                                 api = this,
 173                                 deferred = $.Deferred(),
 174                                 nonce = getNonce(),
 175                                 id = 'uploadframe-' + nonce,
 176                                 $form = $( '<form>' ),
 177                                 iframe = getNewIframe( id ),
 178                                 $iframe = $( iframe );
 179
 180                         for ( key in data ) {
 181                                 if ( !fieldsAllowed[ key ] ) {
 182                                         delete data[ key ];
 183                                 }
 184                         }
 185
 186                         data = $.extend( {}, this.defaults.parameters, { action: 'upload' }, data );
 187                         $form.addClass( 'mw-api-upload-form' );
 188
 189                         $form.css( 'display', 'none' )
 190                                 .attr( {
 191                                         action: this.defaults.ajax.url,
 192                                         method: 'POST',
 193                                         target: id,
 194                                         enctype: 'multipart/form-data'
 195                                 } );
 196
 197                         $iframe.one( 'load', function () {
 198                                 $iframe.one( 'load', function () {
 199                                         var result = processIframeResult( iframe );
 200                                         deferred.notify( 1 );
 201
 202                                         if ( !result ) {
 203                                                 deferred.reject( 'ok-but-empty', 'No response from API on upload attempt.' );
 204                                         } else if ( result.error ) {
 205                                                 if ( result.error.code === 'badtoken' ) {
 206                                                         api.badToken( 'edit' );
 207                                                 }
 208
 209                                                 deferred.reject( result.error.code, result );
 210                                         } else if ( result.upload && result.upload.warnings ) {
 211                                                 deferred.reject( getFirstKey( result.upload.warnings ), result );
 212                                         } else {
 213                                                 deferred.resolve( result );
 214                                         }
 215                                 } );
 216                                 tokenPromise.done( function () {
 217                                         $form.submit();
 218                                 } );
 219                         } );
 220
 221                         $iframe.error( function ( error ) {
 222                                 deferred.reject( 'http', error );
 223                         } );
 224
 225                         $iframe.prop( 'src', 'about:blank' ).hide();
 226
 227                         file.name = 'file';
 228
 229                         $.each( data, function ( key, val ) {
 230                                 $form.append( getHiddenInput( key, val ) );
 231                         } );
 232
 233                         if ( !data.filename && !data.stash ) {
 234                                 throw new Error( 'Filename not included in file data.' );
 235                         }
 236
 237                         if ( this.needToken() ) {
 238                                 this.getEditToken().then( function ( token ) {
 239                                         $form.append( getHiddenInput( 'token', token ) );
 240                                         tokenPromise.resolve();
 241                                 }, tokenPromise.reject );
 242                         } else {
 243                                 tokenPromise.resolve();
 244                         }
 245
 246                         $( 'body' ).append( $form, $iframe );
 247
 248                         deferred.always( function () {
 249                                 $form.remove();
 250                                 $iframe.remove();
 251                         } );
 252
 253                         return deferred.promise();
 254                 },
 255
 256                 /**
 257                  * Uploads a file using the FormData API.
 258                  *
 259                  * @private
 260                  * @param {File} file
 261                  * @param {Object} data Other upload options, see action=upload API docs for more
 262                  * @return {jQuery.Promise}
 263                  */
 264                 uploadWithFormData: function ( file, data ) {
 265                         var key,
 266                                 deferred = $.Deferred();
 267
 268                         for ( key in data ) {
 269                                 if ( !fieldsAllowed[ key ] ) {
 270                                         delete data[ key ];
 271                                 }
 272                         }
 273
 274                         data = $.extend( {}, this.defaults.parameters, { action: 'upload' }, data );
 275                         data.file = file;
 276
 277                         if ( !data.filename && !data.stash ) {
 278                                 throw new Error( 'Filename not included in file data.' );
 279                         }
 280
 281                         // Use this.postWithEditToken() or this.post()
 282                         this[ this.needToken() ? 'postWithEditToken' : 'post' ]( data, {
 283                                 // Use FormData (if we got here, we know that it's available)
 284                                 contentType: 'multipart/form-data',
 285                                 // Provide upload progress notifications
 286                                 xhr: function () {
 287                                         var xhr = $.ajaxSettings.xhr();
 288                                         if ( xhr.upload ) {
 289                                                 // need to bind this event before we open the connection (see note at
 290                                                 // https://developer.mozilla.org/en-US/docs/DOM/XMLHttpRequest/Using_XMLHttpRequest#Monitoring_progress)
 291                                                 xhr.upload.addEventListener( 'progress', function ( ev ) {
 292                                                         if ( ev.lengthComputable ) {
 293                                                                 deferred.notify( ev.loaded / ev.total );
 294                                                         }
 295                                                 } );
 296                                         }
 297                                         return xhr;
 298                                 }
 299                         } )
 300                                 .done( function ( result ) {
 301                                         deferred.notify( 1 );
 302                                         if ( result.upload && result.upload.warnings ) {
 303                                                 deferred.reject( getFirstKey( result.upload.warnings ), result );
 304                                         } else {
 305                                                 deferred.resolve( result );
 306                                         }
 307                                 } )
 308                                 .fail( function ( errorCode, result ) {
 309                                         deferred.notify( 1 );
 310                                         deferred.reject( errorCode, result );
 311                                 } );
 312
 313                         return deferred.promise();
 314                 },
 315
 316                 /**
 317                  * Upload a file to the stash.
 318                  *
 319                  * This function will return a promise, which when resolved, will pass back a function
 320                  * to finish the stash upload. You can call that function with an argument containing
 321                  * more, or conflicting, data to pass to the server. For example:
 322                  *
 323                  *     // upload a file to the stash with a placeholder filename
 324                  *     api.uploadToStash( file, { filename: 'testing.png' } ).done( function ( finish ) {
 325                  *         // finish is now the function we can use to finalize the upload
 326                  *         // pass it a new filename from user input to override the initial value
 327                  *         finish( { filename: getFilenameFromUser() } ).done( function ( data ) {
 328                  *             // the upload is complete, data holds the API response
 329                  *         } );
 330                  *     } );
 331                  *
 332                  * @param {File|HTMLInputElement} file
 333                  * @param {Object} [data]
 334                  * @return {jQuery.Promise}
 335                  * @return {Function} return.finishStashUpload Call this function to finish the upload.
 336                  * @return {Object} return.finishStashUpload.data Additional data for the upload.
 337                  * @return {jQuery.Promise} return.finishStashUpload.return API promise for the final upload
 338                  * @return {Object} return.finishStashUpload.return.data API return value for the final upload
 339                  */
 340                 uploadToStash: function ( file, data ) {
 341                         var filekey,
 342                                 api = this;
 343
 344                         if ( !data.filename ) {
 345                                 throw new Error( 'Filename not included in file data.' );
 346                         }
 347
 348                         function finishUpload( moreData ) {
 349                                 data = $.extend( data, moreData );
 350                                 data.filekey = filekey;
 351                                 data.action = 'upload';
 352                                 data.format = 'json';
 353
 354                                 if ( !data.filename ) {
 355                                         throw new Error( 'Filename not included in file data.' );
 356                                 }
 357
 358                                 return api.postWithEditToken( data ).then( function ( result ) {
 359                                         if ( result.upload && result.upload.warnings ) {
 360                                                 return $.Deferred().reject( getFirstKey( result.upload.warnings ), result ).promise();
 361                                         }
 362                                         return result;
 363                                 } );
 364                         }
 365
 366                         return this.upload( file, { stash: true, filename: data.filename } ).then(
 367                                 function ( result ) {
 368                                         filekey = result.upload.filekey;
 369                                         return finishUpload;
 370                                 },
 371                                 function ( errorCode, result ) {
 372                                         if ( result && result.upload && result.upload.filekey ) {
 373                                                 // Ignore any warnings if 'filekey' was returned, that's all we care about
 374                                                 filekey = result.upload.filekey;
 375                                                 return $.Deferred().resolve( finishUpload );
 376                                         }
 377                                         return $.Deferred().reject( errorCode, result );
 378                                 }
 379                         );
 380                 },
 381
 382                 needToken: function () {
 383                         return true;
 384                 }
 385         } );
 386
 387         /**
 388          * @class mw.Api
 389          * @mixins mw.Api.plugin.upload
 390          */
 391 }( mediaWiki, jQuery ) );