michael@0: /* This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0:  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: const EXPORTED_SYMBOLS = ["httpRequest", "percentEncode"];
michael@0: 
michael@0: const {classes: Cc, interfaces: Ci, utils: Cu} = Components;
michael@0: 
michael@0: // Strictly follow RFC 3986 when encoding URI components.
michael@0: // Accepts a unescaped string and returns the URI encoded string for use in
michael@0: // an HTTP request.
michael@0: function percentEncode(aString)
michael@0:   encodeURIComponent(aString).replace(/[!'()]/g, escape).replace(/\*/g, "%2A");
michael@0: 
michael@0: /*
michael@0:  * aOptions can have a variety of fields:
michael@0:  *  headers, an array of headers
michael@0:  *  postData, this can be:
michael@0:  *    a string: send it as is
michael@0:  *    an array of parameters: encode as form values
michael@0:  *    null/undefined: no POST data.
michael@0:  *  method, GET, POST or PUT (this is set automatically if postData exists).
michael@0:  *  onLoad, a function handle to call when the load is complete, it takes two
michael@0:  *          parameters: the responseText and the XHR object.
michael@0:  *  onError, a function handle to call when an error occcurs, it takes three
michael@0:  *          parameters: the error, the responseText and the XHR object.
michael@0:  *  logger, an object that implements the debug and log methods (e.g. log.jsm).
michael@0:  *
michael@0:  * Headers or post data are given as an array of arrays, for each each inner
michael@0:  * array the first value is the key and the second is the value, e.g.
michael@0:  *  [["key1", "value1"], ["key2", "value2"]].
michael@0:  */
michael@0: function httpRequest(aUrl, aOptions) {
michael@0:   let xhr = Cc["@mozilla.org/xmlextras/xmlhttprequest;1"]
michael@0:               .createInstance(Ci.nsIXMLHttpRequest);
michael@0:   xhr.mozBackgroundRequest = true; // no error dialogs
michael@0:   xhr.open(aOptions.method || (aOptions.postData ? "POST" : "GET"), aUrl);
michael@0:   xhr.channel.loadFlags = Ci.nsIChannel.LOAD_ANONYMOUS | // don't send cookies
michael@0:                           Ci.nsIChannel.LOAD_BYPASS_CACHE |
michael@0:                           Ci.nsIChannel.INHIBIT_CACHING;
michael@0:   xhr.onerror = function(aProgressEvent) {
michael@0:     if (aOptions.onError) {
michael@0:       // adapted from toolkit/mozapps/extensions/nsBlocklistService.js
michael@0:       let request = aProgressEvent.target;
michael@0:       let status;
michael@0:       try {
michael@0:         // may throw (local file or timeout)
michael@0:         status = request.status;
michael@0:       }
michael@0:       catch (e) {
michael@0:         request = request.channel.QueryInterface(Ci.nsIRequest);
michael@0:         status = request.status;
michael@0:       }
michael@0:       // When status is 0 we don't have a valid channel.
michael@0:       let statusText = status ? request.statusText : "offline";
michael@0:       aOptions.onError(statusText, null, this);
michael@0:     }
michael@0:   };
michael@0:   xhr.onload = function(aRequest) {
michael@0:     try {
michael@0:       let target = aRequest.target;
michael@0:       if (aOptions.logger)
michael@0:         aOptions.logger.debug("Received response: " + target.responseText);
michael@0:       if (target.status < 200 || target.status >= 300) {
michael@0:         let errorText = target.responseText;
michael@0:         if (!errorText || /<(ht|\?x)ml\b/i.test(errorText))
michael@0:           errorText = target.statusText;
michael@0:         throw target.status + " - " + errorText;
michael@0:       }
michael@0:       if (aOptions.onLoad)
michael@0:         aOptions.onLoad(target.responseText, this);
michael@0:     } catch (e) {
michael@0:       Cu.reportError(e);
michael@0:       if (aOptions.onError)
michael@0:         aOptions.onError(e, aRequest.target.responseText, this);
michael@0:     }
michael@0:   };
michael@0: 
michael@0:   if (aOptions.headers) {
michael@0:     aOptions.headers.forEach(function(header) {
michael@0:       xhr.setRequestHeader(header[0], header[1]);
michael@0:     });
michael@0:   }
michael@0: 
michael@0:   // Handle adding postData as defined above.
michael@0:   let POSTData = aOptions.postData || "";
michael@0:   if (Array.isArray(POSTData)) {
michael@0:     xhr.setRequestHeader("Content-Type",
michael@0:                          "application/x-www-form-urlencoded; charset=utf-8");
michael@0:     POSTData = POSTData.map(function(p) p[0] + "=" + percentEncode(p[1]))
michael@0:                        .join("&");
michael@0:   }
michael@0: 
michael@0:   if (aOptions.logger) {
michael@0:     aOptions.logger.log("sending request to " + aUrl + " (POSTData = " +
michael@0:                         POSTData + ")");
michael@0:   }
michael@0:   xhr.send(POSTData);
michael@0:   return xhr;
michael@0: }