Merge "Upstream EasyDeflate library from VisualEditor"

[lhc/web/wiklou.git] / resources / src / mediawiki.api / upload.js

/**
 * Provides an interface for uploading files to MediaWiki.
 *
 * @class mw.Api.plugin.upload
 * @singleton
 */
( function ( mw, $ ) {
        var nonce = 0,
                fieldsAllowed = {
                        stash: true,
                        filekey: true,
                        filename: true,
                        comment: true,
                        text: true,
                        watchlist: true,
                        ignorewarnings: true,
                        chunk: true,
                        offset: true,
                        filesize: true,
                        async: true
                };

        /**
         * Get nonce for iframe IDs on the page.
         *
         * @private
         * @return {number}
         */
        function getNonce() {
                return nonce++;
        }

        /**
         * Given a non-empty object, return one of its keys.
         *
         * @private
         * @param {Object} obj
         * @return {string}
         */
        function getFirstKey( obj ) {
                var key;
                for ( key in obj ) {
                        return key;
                }
        }

        /**
         * Get new iframe object for an upload.
         *
         * @private
         * @param {string} id
         * @return {HTMLIframeElement}
         */
        function getNewIframe( id ) {
                var frame = document.createElement( 'iframe' );
                frame.id = id;
                frame.name = id;
                return frame;
        }

        /**
         * Shortcut for getting hidden inputs
         *
         * @private
         * @param {string} name
         * @param {string} val
         * @return {jQuery}
         */
        function getHiddenInput( name, val ) {
                return $( '<input>' ).attr( 'type', 'hidden' )
                        .attr( 'name', name )
                        .val( val );
        }

        /**
         * Process the result of the form submission, returned to an iframe.
         * This is the iframe's onload event.
         *
         * @param {HTMLIframeElement} iframe Iframe to extract result from
         * @return {Object} Response from the server. The return value may or may
         *   not be an XMLDocument, this code was copied from elsewhere, so if you
         *   see an unexpected return type, please file a bug.
         */
        function processIframeResult( iframe ) {
                var json,
                        doc = iframe.contentDocument || frames[ iframe.id ].document;

                if ( doc.XMLDocument ) {
                        // The response is a document property in IE
                        return doc.XMLDocument;
                }

                if ( doc.body ) {
                        // Get the json string
                        // We're actually searching through an HTML doc here --
                        // according to mdale we need to do this
                        // because IE does not load JSON properly in an iframe
                        json = $( doc.body ).find( 'pre' ).text();

                        return JSON.parse( json );
                }

                // Response is a xml document
                return doc;
        }

        function formDataAvailable() {
                return window.FormData !== undefined &&
                        window.File !== undefined &&
                        window.File.prototype.slice !== undefined;
        }

        $.extend( mw.Api.prototype, {
                /**
                 * Upload a file to MediaWiki.
                 *
                 * The file will be uploaded using AJAX and FormData, if the browser supports it, or via an
                 * iframe if it doesn't.
                 *
                 * Caveats of iframe upload:
                 * - The returned jQuery.Promise will not receive `progress` notifications during the upload
                 * - It is incompatible with uploads to a foreign wiki using mw.ForeignApi
                 * - You must pass a HTMLInputElement and not a File for it to be possible
                 *
                 * @param {HTMLInputElement|File|Blob} file HTML input type=file element with a file already inside
                 *  of it, or a File object.
                 * @param {Object} data Other upload options, see action=upload API docs for more
                 * @return {jQuery.Promise}
                 */
                upload: function ( file, data ) {
                        var isFileInput, canUseFormData;

                        isFileInput = file && file.nodeType === Node.ELEMENT_NODE;

                        if ( formDataAvailable() && isFileInput && file.files ) {
                                file = file.files[ 0 ];
                        }

                        if ( !file ) {
                                throw new Error( 'No file' );
                        }

                        // Blobs are allowed in formdata uploads, it turns out
                        canUseFormData = formDataAvailable() && ( file instanceof window.File || file instanceof window.Blob );

                        if ( !isFileInput && !canUseFormData ) {
                                throw new Error( 'Unsupported argument type passed to mw.Api.upload' );
                        }

                        if ( canUseFormData ) {
                                return this.uploadWithFormData( file, data );
                        }

                        return this.uploadWithIframe( file, data );
                },

                /**
                 * Upload a file to MediaWiki with an iframe and a form.
                 *
                 * This method is necessary for browsers without the File/FormData
                 * APIs, and continues to work in browsers with those APIs.
                 *
                 * The rough sketch of how this method works is as follows:
                 * 1. An iframe is loaded with no content.
                 * 2. A form is submitted with the passed-in file input and some extras.
                 * 3. The MediaWiki API receives that form data, and sends back a response.
                 * 4. The response is sent to the iframe, because we set target=(iframe id)
                 * 5. The response is parsed out of the iframe's document, and passed back
                 *    through the promise.
                 *
                 * @private
                 * @param {HTMLInputElement} file The file input with a file in it.
                 * @param {Object} data Other upload options, see action=upload API docs for more
                 * @return {jQuery.Promise}
                 */
                uploadWithIframe: function ( file, data ) {
                        var key,
                                tokenPromise = $.Deferred(),
                                api = this,
                                deferred = $.Deferred(),
                                nonce = getNonce(),
                                id = 'uploadframe-' + nonce,
                                $form = $( '<form>' ),
                                iframe = getNewIframe( id ),
                                $iframe = $( iframe );

                        for ( key in data ) {
                                if ( !fieldsAllowed[ key ] ) {
                                        delete data[ key ];
                                }
                        }

                        data = $.extend( {}, this.defaults.parameters, { action: 'upload' }, data );
                        $form.addClass( 'mw-api-upload-form' );

                        $form.css( 'display', 'none' )
                                .attr( {
                                        action: this.defaults.ajax.url,
                                        method: 'POST',
                                        target: id,
                                        enctype: 'multipart/form-data'
                                } );

                        $iframe.one( 'load', function () {
                                $iframe.one( 'load', function () {
                                        var result = processIframeResult( iframe );
                                        deferred.notify( 1 );

                                        if ( !result ) {
                                                deferred.reject( 'ok-but-empty', 'No response from API on upload attempt.' );
                                        } else if ( result.error ) {
                                                if ( result.error.code === 'badtoken' ) {
                                                        api.badToken( 'csrf' );
                                                }

                                                deferred.reject( result.error.code, result );
                                        } else if ( result.upload && result.upload.warnings ) {
                                                deferred.reject( getFirstKey( result.upload.warnings ), result );
                                        } else {
                                                deferred.resolve( result );
                                        }
                                } );
                                tokenPromise.done( function () {
                                        $form.submit();
                                } );
                        } );

                        $iframe.on( 'error', function ( error ) {
                                deferred.reject( 'http', error );
                        } );

                        $iframe.prop( 'src', 'about:blank' ).hide();

                        file.name = 'file';

                        $.each( data, function ( key, val ) {
                                $form.append( getHiddenInput( key, val ) );
                        } );

                        if ( !data.filename && !data.stash ) {
                                throw new Error( 'Filename not included in file data.' );
                        }

                        if ( this.needToken() ) {
                                this.getEditToken().then( function ( token ) {
                                        $form.append( getHiddenInput( 'token', token ) );
                                        tokenPromise.resolve();
                                }, tokenPromise.reject );
                        } else {
                                tokenPromise.resolve();
                        }

                        $( 'body' ).append( $form, $iframe );

                        deferred.always( function () {
                                $form.remove();
                                $iframe.remove();
                        } );

                        return deferred.promise();
                },

                /**
                 * Uploads a file using the FormData API.
                 *
                 * @private
                 * @param {File} file
                 * @param {Object} data Other upload options, see action=upload API docs for more
                 * @return {jQuery.Promise}
                 */
                uploadWithFormData: function ( file, data ) {
                        var key, request,
                                deferred = $.Deferred();

                        for ( key in data ) {
                                if ( !fieldsAllowed[ key ] ) {
                                        delete data[ key ];
                                }
                        }

                        data = $.extend( {}, this.defaults.parameters, { action: 'upload' }, data );
                        if ( !data.chunk ) {
                                data.file = file;
                        }

                        if ( !data.filename && !data.stash ) {
                                throw new Error( 'Filename not included in file data.' );
                        }

                        // Use this.postWithEditToken() or this.post()
                        request = this[ this.needToken() ? 'postWithEditToken' : 'post' ]( data, {
                                // Use FormData (if we got here, we know that it's available)
                                contentType: 'multipart/form-data',
                                // No timeout (default from mw.Api is 30 seconds)
                                timeout: 0,
                                // Provide upload progress notifications
                                xhr: function () {
                                        var xhr = $.ajaxSettings.xhr();
                                        if ( xhr.upload ) {
                                                // need to bind this event before we open the connection (see note at
                                                // https://developer.mozilla.org/en-US/docs/DOM/XMLHttpRequest/Using_XMLHttpRequest#Monitoring_progress)
                                                xhr.upload.addEventListener( 'progress', function ( ev ) {
                                                        if ( ev.lengthComputable ) {
                                                                deferred.notify( ev.loaded / ev.total );
                                                        }
                                                } );
                                        }
                                        return xhr;
                                }
                        } )
                                .done( function ( result ) {
                                        deferred.notify( 1 );
                                        if ( result.upload && result.upload.warnings ) {
                                                deferred.reject( getFirstKey( result.upload.warnings ), result );
                                        } else {
                                                deferred.resolve( result );
                                        }
                                } )
                                .fail( function ( errorCode, result ) {
                                        deferred.notify( 1 );
                                        deferred.reject( errorCode, result );
                                } );

                        return deferred.promise( { abort: request.abort } );
                },

                /**
                 * Upload a file in several chunks.
                 *
                 * @param {File} file
                 * @param {Object} data Other upload options, see action=upload API docs for more
                 * @param {number} [chunkSize] Size (in bytes) per chunk (default: 5MB)
                 * @param {number} [chunkRetries] Amount of times to retry a failed chunk (default: 1)
                 * @return {jQuery.Promise}
                 */
                chunkedUpload: function ( file, data, chunkSize, chunkRetries ) {
                        var start, end, promise, next, active,
                                deferred = $.Deferred();

                        chunkSize = chunkSize === undefined ? 5 * 1024 * 1024 : chunkSize;
                        chunkRetries = chunkRetries === undefined ? 1 : chunkRetries;

                        if ( !data.filename ) {
                                throw new Error( 'Filename not included in file data.' );
                        }

                        // Submit first chunk to get the filekey
                        active = promise = this.uploadChunk( file, data, 0, chunkSize, '', chunkRetries )
                                .done( chunkSize >= file.size ? deferred.resolve : null )
                                .fail( deferred.reject )
                                .progress( deferred.notify );

                        // Now iteratively submit the rest of the chunks
                        for ( start = chunkSize; start < file.size; start += chunkSize ) {
                                end = Math.min( start + chunkSize, file.size );
                                next = $.Deferred();

                                // We could simply chain one this.uploadChunk after another with
                                // .then(), but then we'd hit an `Uncaught RangeError: Maximum
                                // call stack size exceeded` at as low as 1024 calls in Firefox
                                // 47. This'll work around it, but comes with the drawback of
                                // having to properly relay the results to the returned promise.
                                // eslint-disable-next-line no-loop-func
                                promise.done( function ( start, end, next, result ) {
                                        var filekey = result.upload.filekey;
                                        active = this.uploadChunk( file, data, start, end, filekey, chunkRetries )
                                                .done( end === file.size ? deferred.resolve : next.resolve )
                                                .fail( deferred.reject )
                                                .progress( deferred.notify );
                                // start, end & next must be bound to closure, or they'd have
                                // changed by the time the promises are resolved
                                }.bind( this, start, end, next ) );

                                promise = next;
                        }

                        return deferred.promise( { abort: active.abort } );
                },

                /**
                 * Uploads 1 chunk.
                 *
                 * @private
                 * @param {File} file
                 * @param {Object} data Other upload options, see action=upload API docs for more
                 * @param {number} start Chunk start position
                 * @param {number} end Chunk end position
                 * @param {string} [filekey] File key, for follow-up chunks
                 * @param {number} [retries] Amount of times to retry request
                 * @return {jQuery.Promise}
                 */
                uploadChunk: function ( file, data, start, end, filekey, retries ) {
                        var upload,
                                api = this,
                                chunk = this.slice( file, start, end );

                        // When uploading in chunks, we're going to be issuing a lot more
                        // requests and there's always a chance of 1 getting dropped.
                        // In such case, it could be useful to try again: a network hickup
                        // doesn't necessarily have to result in upload failure...
                        retries = retries === undefined ? 1 : retries;

                        data.filesize = file.size;
                        data.chunk = chunk;
                        data.offset = start;

                        // filekey must only be added when uploading follow-up chunks; the
                        // first chunk should never have a filekey (it'll be generated)
                        if ( filekey && start !== 0 ) {
                                data.filekey = filekey;
                        }

                        upload = this.uploadWithFormData( file, data );
                        return upload.then(
                                null,
                                function ( code, result ) {
                                        var retry;

                                        // uploadWithFormData will reject uploads with warnings, but
                                        // these warnings could be "harmless" or recovered from
                                        // (e.g. exists-normalized, when it'll be renamed later)
                                        // In the case of (only) a warning, we still want to
                                        // continue the chunked upload until it completes: then
                                        // reject it - at least it's been fully uploaded by then and
                                        // failure handlers have a complete result object (including
                                        // possibly more warnings, e.g. duplicate)
                                        // This matches .upload, which also completes the upload.
                                        if ( result.upload && result.upload.warnings && code in result.upload.warnings ) {
                                                if ( end === file.size ) {
                                                        // uploaded last chunk = reject with result data
                                                        return $.Deferred().reject( code, result );
                                                } else {
                                                        // still uploading chunks = resolve to keep going
                                                        return $.Deferred().resolve( result );
                                                }
                                        }

                                        if ( retries === 0 ) {
                                                return $.Deferred().reject( code, result );
                                        }

                                        // If the call flat out failed, we may want to try again...
                                        retry = api.uploadChunk.bind( this, file, data, start, end, filekey, retries - 1 );
                                        return api.retry( code, result, retry );
                                },
                                function ( fraction ) {
                                        // Since we're only uploading small parts of a file, we
                                        // need to adjust the reported progress to reflect where
                                        // we actually are in the combined upload
                                        return ( start + fraction * ( end - start ) ) / file.size;
                                }
                        ).promise( { abort: upload.abort } );
                },

                /**
                 * Launch the upload anew if it failed because of network issues.
                 *
                 * @private
                 * @param {string} code Error code
                 * @param {Object} result API result
                 * @param {Function} callable
                 * @return {jQuery.Promise}
                 */
                retry: function ( code, result, callable ) {
                        var uploadPromise,
                                retryTimer,
                                deferred = $.Deferred(),
                                // Wrap around the callable, so that once it completes, it'll
                                // resolve/reject the promise we'll return
                                retry = function () {
                                        uploadPromise = callable();
                                        uploadPromise.then( deferred.resolve, deferred.reject );
                                };

                        // Don't retry if the request failed because we aborted it (or if
                        // it's another kind of request failure)
                        if ( code !== 'http' || result.textStatus === 'abort' ) {
                                return deferred.reject( code, result );
                        }

                        retryTimer = setTimeout( retry, 1000 );
                        return deferred.promise( { abort: function () {
                                // Clear the scheduled upload, or abort if already in flight
                                if ( retryTimer ) {
                                        clearTimeout( retryTimer );
                                }
                                if ( uploadPromise.abort ) {
                                        uploadPromise.abort();
                                }
                        } } );
                },

                /**
                 * Slice a chunk out of a File object.
                 *
                 * @private
                 * @param {File} file
                 * @param {number} start
                 * @param {number} stop
                 * @return {Blob}
                 */
                slice: function ( file, start, stop ) {
                        if ( file.mozSlice ) {
                                // FF <= 12
                                return file.mozSlice( start, stop, file.type );
                        } else if ( file.webkitSlice ) {
                                // Chrome <= 20
                                return file.webkitSlice( start, stop, file.type );
                        } else {
                                // On really old browser versions (before slice was prefixed),
                                // slice() would take (start, length) instead of (start, end)
                                // We'll ignore that here...
                                return file.slice( start, stop, file.type );
                        }
                },

                /**
                 * This function will handle how uploads to stash (via uploadToStash or
                 * chunkedUploadToStash) are resolved/rejected.
                 *
                 * After a successful stash, it'll resolve with a callback which, when
                 * called, will finalize the upload in stash (with the given data, or
                 * with additional/conflicting data)
                 *
                 * A failed stash can still be recovered from as long as 'filekey' is
                 * present. In that case, it'll also resolve with the callback to
                 * finalize the upload (all warnings are then ignored.)
                 * Otherwise, it'll just reject as you'd expect, with code & result.
                 *
                 * @private
                 * @param {jQuery.Promise} uploadPromise
                 * @param {Object} data
                 * @return {jQuery.Promise}
                 * @return {Function} return.finishUpload Call this function to finish the upload.
                 * @return {Object} return.finishUpload.data Additional data for the upload.
                 * @return {jQuery.Promise} return.finishUpload.return API promise for the final upload
                 * @return {Object} return.finishUpload.return.data API return value for the final upload
                 */
                finishUploadToStash: function ( uploadPromise, data ) {
                        var filekey,
                                api = this;

                        function finishUpload( moreData ) {
                                return api.uploadFromStash( filekey, $.extend( data, moreData ) );
                        }

                        return uploadPromise.then(
                                function ( result ) {
                                        filekey = result.upload.filekey;
                                        return finishUpload;
                                },
                                function ( errorCode, result ) {
                                        if ( result && result.upload && result.upload.filekey ) {
                                                // Ignore any warnings if 'filekey' was returned, that's all we care about
                                                filekey = result.upload.filekey;
                                                return $.Deferred().resolve( finishUpload );
                                        }
                                        return $.Deferred().reject( errorCode, result );
                                }
                        );
                },

                /**
                 * Upload a file to the stash.
                 *
                 * This function will return a promise, which when resolved, will pass back a function
                 * to finish the stash upload. You can call that function with an argument containing
                 * more, or conflicting, data to pass to the server. For example:
                 *
                 *     // upload a file to the stash with a placeholder filename
                 *     api.uploadToStash( file, { filename: 'testing.png' } ).done( function ( finish ) {
                 *         // finish is now the function we can use to finalize the upload
                 *         // pass it a new filename from user input to override the initial value
                 *         finish( { filename: getFilenameFromUser() } ).done( function ( data ) {
                 *             // the upload is complete, data holds the API response
                 *         } );
                 *     } );
                 *
                 * @param {File|HTMLInputElement} file
                 * @param {Object} [data]
                 * @return {jQuery.Promise}
                 * @return {Function} return.finishUpload Call this function to finish the upload.
                 * @return {Object} return.finishUpload.data Additional data for the upload.
                 * @return {jQuery.Promise} return.finishUpload.return API promise for the final upload
                 * @return {Object} return.finishUpload.return.data API return value for the final upload
                 */
                uploadToStash: function ( file, data ) {
                        var promise;

                        if ( !data.filename ) {
                                throw new Error( 'Filename not included in file data.' );
                        }

                        promise = this.upload( file, { stash: true, filename: data.filename } );

                        return this.finishUploadToStash( promise, data );
                },

                /**
                 * Upload a file to the stash, in chunks.
                 *
                 * This function will return a promise, which when resolved, will pass back a function
                 * to finish the stash upload.
                 *
                 * @see #method-uploadToStash
                 * @param {File|HTMLInputElement} file
                 * @param {Object} [data]
                 * @param {number} [chunkSize] Size (in bytes) per chunk (default: 5MB)
                 * @param {number} [chunkRetries] Amount of times to retry a failed chunk (default: 1)
                 * @return {jQuery.Promise}
                 * @return {Function} return.finishUpload Call this function to finish the upload.
                 * @return {Object} return.finishUpload.data Additional data for the upload.
                 * @return {jQuery.Promise} return.finishUpload.return API promise for the final upload
                 * @return {Object} return.finishUpload.return.data API return value for the final upload
                 */
                chunkedUploadToStash: function ( file, data, chunkSize, chunkRetries ) {
                        var promise;

                        if ( !data.filename ) {
                                throw new Error( 'Filename not included in file data.' );
                        }

                        promise = this.chunkedUpload(
                                file,
                                { stash: true, filename: data.filename },
                                chunkSize,
                                chunkRetries
                        );

                        return this.finishUploadToStash( promise, data );
                },

                /**
                 * Finish an upload in the stash.
                 *
                 * @param {string} filekey
                 * @param {Object} data
                 * @return {jQuery.Promise}
                 */
                uploadFromStash: function ( filekey, data ) {
                        data.filekey = filekey;
                        data.action = 'upload';
                        data.format = 'json';

                        if ( !data.filename ) {
                                throw new Error( 'Filename not included in file data.' );
                        }

                        return this.postWithEditToken( data ).then( function ( result ) {
                                if ( result.upload && result.upload.warnings ) {
                                        return $.Deferred().reject( getFirstKey( result.upload.warnings ), result ).promise();
                                }
                                return result;
                        } );
                },

                needToken: function () {
                        return true;
                }
        } );

        /**
         * @class mw.Api
         * @mixins mw.Api.plugin.upload
         */
}( mediaWiki, jQuery ) );