var CombinedStream = require('combined-stream'); var util = require('util'); var path = require('path'); var http = require('http'); var https = require('https'); var parseUrl = require('url').parse; var fs = require('fs'); var mime = require('mime-types'); var async = require('async'); var populate = require('./populate.js'); // Public API module.exports = FormData; // make it a Stream util.inherits(FormData, CombinedStream); /** * Create readable "multipart/form-data" streams. * Can be used to submit forms * and file uploads to other web applications. * * @constructor */ function FormData() { if (!(this instanceof FormData)) { throw new TypeError('Failed to construct FormData: Please use the _new_ operator, this object constructor cannot be called as a function.'); } this._overheadLength = 0; this._valueLength = 0; this._lengthRetrievers = []; CombinedStream.call(this); } FormData.LINE_BREAK = '\r\n'; FormData.DEFAULT_CONTENT_TYPE = 'application/octet-stream'; FormData.prototype.append = function(field, value, options) { options = options || {}; // allow filename as single option if (typeof options == 'string') { options = {filename: options}; } var append = CombinedStream.prototype.append.bind(this); // all that streamy business can't handle numbers if (typeof value == 'number') { value = '' + value; } // https://github.com/felixge/node-form-data/issues/38 if (util.isArray(value)) { // Please convert your array into string // the way web server expects it this._error(new Error('Arrays are not supported.')); return; } var header = this._multiPartHeader(field, value, options); var footer = this._multiPartFooter(); append(header); append(value); append(footer); // pass along options.knownLength this._trackLength(header, value, options); }; FormData.prototype._trackLength = function(header, value, options) { var valueLength = 0; // used w/ getLengthSync(), when length is known. // e.g. for streaming directly from a remote server, // w/ a known file a size, and not wanting to wait for // incoming file to finish to get its size. if (options.knownLength != null) { valueLength += +options.knownLength; } else if (Buffer.isBuffer(value)) { valueLength = value.length; } else if (typeof value === 'string') { valueLength = Buffer.byteLength(value); } this._valueLength += valueLength; // @check why add CRLF? does this account for custom/multiple CRLFs? this._overheadLength += Buffer.byteLength(header) + FormData.LINE_BREAK.length; // empty or either doesn't have path or not an http response if (!value || ( !value.path && !(value.readable && value.hasOwnProperty('httpVersion')) )) { return; } // no need to bother with the length if (!options.knownLength) { this._lengthRetrievers.push(function(next) { if (value.hasOwnProperty('fd')) { // take read range into a account // `end` = Infinity –> read file till the end // // TODO: Looks like there is bug in Node fs.createReadStream // it doesn't respect `end` options without `start` options // Fix it when node fixes it. // https://github.com/joyent/node/issues/7819 if (value.end != undefined && value.end != Infinity && value.start != undefined) { // when end specified // no need to calculate range // inclusive, starts with 0 next(null, value.end + 1 - (value.start ? value.start : 0)); // not that fast snoopy } else { // still need to fetch file size from fs fs.stat(value.path, function(err, stat) { var fileSize; if (err) { next(err); return; } // update final size based on the range options fileSize = stat.size - (value.start ? value.start : 0); next(null, fileSize); }); } // or http response } else if (value.hasOwnProperty('httpVersion')) { next(null, +value.headers['content-length']); // or request stream http://github.com/mikeal/request } else if (value.hasOwnProperty('httpModule')) { // wait till response come back value.on('response', function(response) { value.pause(); next(null, +response.headers['content-length']); }); value.resume(); // something else } else { next('Unknown stream'); } }); } }; FormData.prototype._multiPartHeader = function(field, value, options) { // custom header specified (as string)? // it becomes responsible for boundary // (e.g. to handle extra CRLFs on .NET servers) if (options.header) { return options.header; } var contentDisposition = this._getContentDisposition(value, options); var contentType = this._getContentType(value, options); var contents = ''; var headers = { // add custom disposition as third element or keep it two elements if not 'Content-Disposition': ['form-data', 'name="' + field + '"'].concat(contentDisposition || []), // if no content type. allow it to be empty array 'Content-Type': [].concat(contentType || []) }; for (var prop in headers) { if (headers[prop].length) { contents += prop + ': ' + headers[prop].join('; ') + FormData.LINE_BREAK; } } return '--' + this.getBoundary() + FormData.LINE_BREAK + contents + FormData.LINE_BREAK; }; FormData.prototype._getContentDisposition = function(value, options) { var contentDisposition; // custom filename takes precedence // fs- and request- streams have path property var filename = options.filename || value.path; // or try http response if (!filename && value.readable && value.hasOwnProperty('httpVersion')) { filename = value.client._httpMessage.path; } if (filename) { contentDisposition = 'filename="' + path.basename(filename) + '"'; } return contentDisposition; }; FormData.prototype._getContentType = function(value, options) { // use custom content-type above all var contentType = options.contentType; // or try `path` from fs-, request- streams if (!contentType && value.path) { contentType = mime.lookup(value.path); } // or if it's http-reponse if (!contentType && value.readable && value.hasOwnProperty('httpVersion')) { contentType = value.headers['content-type']; } // or guess it from the filename if (!contentType && options.filename) { contentType = mime.lookup(options.filename); } // fallback to the default content type if `value` is not simple value if (!contentType && typeof value == 'object') { contentType = FormData.DEFAULT_CONTENT_TYPE; } return contentType; }; FormData.prototype._multiPartFooter = function() { return function(next) { var footer = FormData.LINE_BREAK; var lastPart = (this._streams.length === 0); if (lastPart) { footer += this._lastBoundary(); } next(footer); }.bind(this); }; FormData.prototype._lastBoundary = function() { return '--' + this.getBoundary() + '--' + FormData.LINE_BREAK; }; FormData.prototype.getHeaders = function(userHeaders) { var header; var formHeaders = { 'content-type': 'multipart/form-data; boundary=' + this.getBoundary() }; for (header in userHeaders) { if (userHeaders.hasOwnProperty(header)) { formHeaders[header.toLowerCase()] = userHeaders[header]; } } return formHeaders; }; FormData.prototype.getCustomHeaders = function(contentType) { contentType = contentType ? contentType : 'multipart/form-data'; var formHeaders = { 'content-type': contentType + '; boundary=' + this.getBoundary(), 'content-length': this.getLengthSync() }; return formHeaders; }; FormData.prototype.getBoundary = function() { if (!this._boundary) { this._generateBoundary(); } return this._boundary; }; FormData.prototype._generateBoundary = function() { // This generates a 50 character boundary similar to those used by Firefox. // They are optimized for boyer-moore parsing. var boundary = '--------------------------'; for (var i = 0; i < 24; i++) { boundary += Math.floor(Math.random() * 10).toString(16); } this._boundary = boundary; }; // Note: getLengthSync DOESN'T calculate streams length // As workaround one can calculate file size manually // and add it as knownLength option FormData.prototype.getLengthSync = function() { var knownLength = this._overheadLength + this._valueLength; // Don't get confused, there are 3 "internal" streams for each keyval pair // so it basically checks if there is any value added to the form if (this._streams.length) { knownLength += this._lastBoundary().length; } // https://github.com/form-data/form-data/issues/40 if (this._lengthRetrievers.length) { // Some async length retrievers are present // therefore synchronous length calculation is false. // Please use getLength(callback) to get proper length this._error(new Error('Cannot calculate proper length in synchronous way.')); } return knownLength; }; FormData.prototype.getLength = function(cb) { var knownLength = this._overheadLength + this._valueLength; if (this._streams.length) { knownLength += this._lastBoundary().length; } if (!this._lengthRetrievers.length) { process.nextTick(cb.bind(this, null, knownLength)); return; } async.parallel(this._lengthRetrievers, function(err, values) { if (err) { cb(err); return; } values.forEach(function(length) { knownLength += length; }); cb(null, knownLength); }); }; FormData.prototype.submit = function(params, cb) { var request , options , defaults = {method: 'post'} ; // parse provided url if it's string // or treat it as options object if (typeof params == 'string') { params = parseUrl(params); options = populate({ port: params.port, path: params.pathname, host: params.hostname }, defaults); // use custom params } else { options = populate(params, defaults); // if no port provided use default one if (!options.port) { options.port = options.protocol == 'https:' ? 443 : 80; } } // put that good code in getHeaders to some use options.headers = this.getHeaders(params.headers); // https if specified, fallback to http in any other case if (options.protocol == 'https:') { request = https.request(options); } else { request = http.request(options); } // get content length and fire away this.getLength(function(err, length) { if (err) { this._error(err); return; } // add content length request.setHeader('Content-Length', length); this.pipe(request); if (cb) { request.on('error', cb); request.on('response', cb.bind(this, null)); } }.bind(this)); return request; }; FormData.prototype._error = function(err) { if (!this.error) { this.error = err; this.pause(); this.emit('error', err); } };