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: // A simple class that encapsulates a request. You'll notice the
michael@0: // style here is different from the rest of the extension; that's
michael@0: // because this was re-used from really old code we had. At some
michael@0: // point it might be nice to replace this with something better
michael@0: // (e.g., something that has explicit onerror handler, ability
michael@0: // to set headers, and so on).
michael@0: 
michael@0: /**
michael@0:  * Because we might be in a component, we can't just assume that
michael@0:  * XMLHttpRequest exists. So we use this tiny factory function to wrap the
michael@0:  * XPCOM version.
michael@0:  *
michael@0:  * @return XMLHttpRequest object
michael@0:  */
michael@0: function PROT_NewXMLHttpRequest() {
michael@0:   var Cc = Components.classes;
michael@0:   var Ci = Components.interfaces;
michael@0:   var request = Cc["@mozilla.org/xmlextras/xmlhttprequest;1"]
michael@0:                 .createInstance(Ci.nsIXMLHttpRequest);
michael@0:   // Need the following so we get onerror/load/progresschange
michael@0:   request.QueryInterface(Ci.nsIJSXMLHttpRequest);
michael@0:   return request;
michael@0: }
michael@0: 
michael@0: /**
michael@0:  * A helper class that does HTTP GETs and calls back a function with
michael@0:  * the content it receives. Asynchronous, so uses a closure for the
michael@0:  * callback.
michael@0:  *
michael@0:  * Note, that XMLFetcher is only used for SafeBrowsing, therefore
michael@0:  * we inherit from nsILoadContext, so we can use the callbacks on the
michael@0:  * channel to separate the safebrowsing cookie based on a reserved
michael@0:  * appId.
michael@0:  * @constructor
michael@0:  */
michael@0: function PROT_XMLFetcher() {
michael@0:   this.debugZone = "xmlfetcher";
michael@0:   this._request = PROT_NewXMLHttpRequest();
michael@0:   // implements nsILoadContext
michael@0:   this.appId = Ci.nsIScriptSecurityManager.SAFEBROWSING_APP_ID;
michael@0:   this.isInBrowserElement = false;
michael@0:   this.usePrivateBrowsing = false;
michael@0:   this.isContent = false;
michael@0: }
michael@0: 
michael@0: PROT_XMLFetcher.prototype = {
michael@0:   /**
michael@0:    * Function that will be called back upon fetch completion.
michael@0:    */
michael@0:   _callback: null,
michael@0:   
michael@0: 
michael@0:   /**
michael@0:    * Fetches some content.
michael@0:    * 
michael@0:    * @param page URL to fetch
michael@0:    * @param callback Function to call back when complete.
michael@0:    */
michael@0:   get: function(page, callback) {
michael@0:     this._request.abort();                // abort() is asynchronous, so
michael@0:     this._request = PROT_NewXMLHttpRequest();
michael@0:     this._callback = callback;
michael@0:     var asynchronous = true;
michael@0:     this._request.open("GET", page, asynchronous);
michael@0:     this._request.channel.notificationCallbacks = this;
michael@0: 
michael@0:     // Create a closure
michael@0:     var self = this;
michael@0:     this._request.addEventListener("readystatechange", function() {
michael@0:       self.readyStateChange(self);
michael@0:     }, false);
michael@0: 
michael@0:     this._request.send(null);
michael@0:   },
michael@0: 
michael@0:   cancel: function() {
michael@0:     this._request.abort();
michael@0:     this._request = null;
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * Called periodically by the request to indicate some state change. 4
michael@0:    * means content has been received.
michael@0:    */
michael@0:   readyStateChange: function(fetcher) {
michael@0:     if (fetcher._request.readyState != 4)
michael@0:       return;
michael@0: 
michael@0:     // If the request fails, on trunk we get status set to
michael@0:     // NS_ERROR_NOT_AVAILABLE.  On 1.8.1 branch we get an exception
michael@0:     // forwarded from nsIHttpChannel::GetResponseStatus.  To be consistent
michael@0:     // between branch and trunk, we send back NS_ERROR_NOT_AVAILABLE for
michael@0:     // http failures.
michael@0:     var responseText = null;
michael@0:     var status = Components.results.NS_ERROR_NOT_AVAILABLE;
michael@0:     try {
michael@0:       G_Debug(this, "xml fetch status code: \"" + 
michael@0:               fetcher._request.status + "\"");
michael@0:       status = fetcher._request.status;
michael@0:       responseText = fetcher._request.responseText;
michael@0:     } catch(e) {
michael@0:       G_Debug(this, "Caught exception trying to read xmlhttprequest " +
michael@0:               "status/response.");
michael@0:       G_Debug(this, e);
michael@0:     }
michael@0:     if (fetcher._callback)
michael@0:       fetcher._callback(responseText, status);
michael@0:   },
michael@0: 
michael@0:   // nsIInterfaceRequestor
michael@0:   getInterface: function(iid) {
michael@0:     return this.QueryInterface(iid);
michael@0:   },
michael@0: 
michael@0:   QueryInterface: XPCOMUtils.generateQI([Ci.nsIInterfaceRequestor,
michael@0:                                          Ci.nsISupports,
michael@0:                                          Ci.nsILoadContext])
michael@0: };