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 SEARCH_RESPONSE_SUGGESTION_JSON = "application/x-suggestions+json";
michael@0: 
michael@0: const BROWSER_SUGGEST_PREF = "browser.search.suggest.enabled";
michael@0: const XPCOM_SHUTDOWN_TOPIC              = "xpcom-shutdown";
michael@0: const NS_PREFBRANCH_PREFCHANGE_TOPIC_ID = "nsPref:changed";
michael@0: 
michael@0: const Cc = Components.classes;
michael@0: const Ci = Components.interfaces;
michael@0: const Cr = Components.results;
michael@0: const Cu = Components.utils;
michael@0: 
michael@0: const HTTP_OK                    = 200;
michael@0: const HTTP_INTERNAL_SERVER_ERROR = 500;
michael@0: const HTTP_BAD_GATEWAY           = 502;
michael@0: const HTTP_SERVICE_UNAVAILABLE   = 503;
michael@0: 
michael@0: Cu.import("resource://gre/modules/XPCOMUtils.jsm");
michael@0: Cu.import("resource://gre/modules/nsFormAutoCompleteResult.jsm");
michael@0: Cu.import("resource://gre/modules/Services.jsm");
michael@0: 
michael@0: /**
michael@0:  * SuggestAutoComplete is a base class that implements nsIAutoCompleteSearch
michael@0:  * and can collect results for a given search by using the search URL supplied
michael@0:  * by the subclass. We do it this way since the AutoCompleteController in
michael@0:  * Mozilla requires a unique XPCOM Service for every search provider, even if
michael@0:  * the logic for two providers is identical.
michael@0:  * @constructor
michael@0:  */
michael@0: function SuggestAutoComplete() {
michael@0:   this._init();
michael@0: }
michael@0: SuggestAutoComplete.prototype = {
michael@0: 
michael@0:   _init: function() {
michael@0:     this._addObservers();
michael@0:     this._suggestEnabled = Services.prefs.getBoolPref(BROWSER_SUGGEST_PREF);
michael@0:   },
michael@0: 
michael@0:   get _suggestionLabel() {
michael@0:     delete this._suggestionLabel;
michael@0:     let bundle = Services.strings.createBundle("chrome://global/locale/search/search.properties");
michael@0:     return this._suggestionLabel = bundle.GetStringFromName("suggestion_label");
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * Search suggestions will be shown if this._suggestEnabled is true.
michael@0:    */
michael@0:   _suggestEnabled: null,
michael@0: 
michael@0:   /*************************************************************************
michael@0:    * Server request backoff implementation fields below
michael@0:    * These allow us to throttle requests if the server is getting hammered.
michael@0:    **************************************************************************/
michael@0: 
michael@0:   /**
michael@0:    * This is an array that contains the timestamps (in unixtime) of
michael@0:    * the last few backoff-triggering errors.
michael@0:    */
michael@0:   _serverErrorLog: [],
michael@0: 
michael@0:   /**
michael@0:    * If we receive this number of backoff errors within the amount of time
michael@0:    * specified by _serverErrorPeriod, then we initiate backoff.
michael@0:    */
michael@0:   _maxErrorsBeforeBackoff: 3,
michael@0: 
michael@0:   /**
michael@0:    * If we receive enough consecutive errors (where "enough" is defined by
michael@0:    * _maxErrorsBeforeBackoff above) within this time period,
michael@0:    * we trigger the backoff behavior.
michael@0:    */
michael@0:   _serverErrorPeriod: 600000,  // 10 minutes in milliseconds
michael@0: 
michael@0:   /**
michael@0:    * If we get another backoff error immediately after timeout, we increase the
michael@0:    * backoff to (2 x old period) + this value.
michael@0:    */
michael@0:   _serverErrorTimeoutIncrement: 600000,  // 10 minutes in milliseconds
michael@0: 
michael@0:   /**
michael@0:    * The current amount of time to wait before trying a server request
michael@0:    * after receiving a backoff error.
michael@0:    */
michael@0:   _serverErrorTimeout: 0,
michael@0: 
michael@0:   /**
michael@0:    * Time (in unixtime) after which we're allowed to try requesting again.
michael@0:    */
michael@0:   _nextRequestTime: 0,
michael@0: 
michael@0:   /**
michael@0:    * The last engine we requested against (so that we can tell if the
michael@0:    * user switched engines).
michael@0:    */
michael@0:   _serverErrorEngine: null,
michael@0: 
michael@0:   /**
michael@0:    * The XMLHttpRequest object.
michael@0:    * @private
michael@0:    */
michael@0:   _request: null,
michael@0: 
michael@0:   /**
michael@0:    * The object implementing nsIAutoCompleteObserver that we notify when
michael@0:    * we have found results
michael@0:    * @private
michael@0:    */
michael@0:   _listener: null,
michael@0: 
michael@0:   /**
michael@0:    * If this is true, we'll integrate form history results with the
michael@0:    * suggest results.
michael@0:    */
michael@0:   _includeFormHistory: true,
michael@0: 
michael@0:   /**
michael@0:    * True if a request for remote suggestions was sent. This is used to
michael@0:    * differentiate between the "_request is null because the request has
michael@0:    * already returned a result" and "_request is null because no request was
michael@0:    * sent" cases.
michael@0:    */
michael@0:   _sentSuggestRequest: false,
michael@0: 
michael@0:   /**
michael@0:    * This is the callback for the suggest timeout timer.
michael@0:    */
michael@0:   notify: function SAC_notify(timer) {
michael@0:     // FIXME: bug 387341
michael@0:     // Need to break the cycle between us and the timer.
michael@0:     this._formHistoryTimer = null;
michael@0: 
michael@0:     // If this._listener is null, we've already sent out suggest results, so
michael@0:     // nothing left to do here.
michael@0:     if (!this._listener)
michael@0:       return;
michael@0: 
michael@0:     // Otherwise, the XMLHTTPRequest for suggest results is taking too long,
michael@0:     // so send out the form history results and cancel the request.
michael@0:     this._listener.onSearchResult(this, this._formHistoryResult);
michael@0:     this._reset();
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * This determines how long (in ms) we should wait before giving up on
michael@0:    * the suggestions and just showing local form history results.
michael@0:    */
michael@0:   _suggestionTimeout: 500,
michael@0: 
michael@0:   /**
michael@0:    * This is the callback for that the form history service uses to
michael@0:    * send us results.
michael@0:    */
michael@0:   onSearchResult: function SAC_onSearchResult(search, result) {
michael@0:     this._formHistoryResult = result;
michael@0: 
michael@0:     if (this._request) {
michael@0:       // We still have a pending request, wait a bit to give it a chance to
michael@0:       // finish.
michael@0:       this._formHistoryTimer = Cc["@mozilla.org/timer;1"].
michael@0:                                createInstance(Ci.nsITimer);
michael@0:       this._formHistoryTimer.initWithCallback(this, this._suggestionTimeout,
michael@0:                                               Ci.nsITimer.TYPE_ONE_SHOT);
michael@0:     } else if (!this._sentSuggestRequest) {
michael@0:       // We didn't send a request, so just send back the form history results.
michael@0:       this._listener.onSearchResult(this, this._formHistoryResult);
michael@0:       this._reset();
michael@0:     }
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * This is the URI that the last suggest request was sent to.
michael@0:    */
michael@0:   _suggestURI: null,
michael@0: 
michael@0:   /**
michael@0:    * Autocomplete results from the form history service get stored here.
michael@0:    */
michael@0:   _formHistoryResult: null,
michael@0: 
michael@0:   /**
michael@0:    * This holds the suggest server timeout timer, if applicable.
michael@0:    */
michael@0:   _formHistoryTimer: null,
michael@0: 
michael@0:   /**
michael@0:    * Maximum number of history items displayed. This is capped at 7
michael@0:    * because the primary consumer (Firefox search bar) displays 10 rows
michael@0:    * by default, and so we want to leave some space for suggestions
michael@0:    * to be visible.
michael@0:    */
michael@0:   _historyLimit: 7,
michael@0: 
michael@0:   /**
michael@0:    * This clears all the per-request state.
michael@0:    */
michael@0:   _reset: function SAC_reset() {
michael@0:     // Don't let go of our listener and form history result if the timer is
michael@0:     // still pending, the timer will call _reset() when it fires.
michael@0:     if (!this._formHistoryTimer) {
michael@0:       this._listener = null;
michael@0:       this._formHistoryResult = null;
michael@0:     }
michael@0:     this._request = null;
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * This sends an autocompletion request to the form history service,
michael@0:    * which will call onSearchResults with the results of the query.
michael@0:    */
michael@0:   _startHistorySearch: function SAC_SHSearch(searchString, searchParam) {
michael@0:     var formHistory =
michael@0:       Cc["@mozilla.org/autocomplete/search;1?name=form-history"].
michael@0:       createInstance(Ci.nsIAutoCompleteSearch);
michael@0:     formHistory.startSearch(searchString, searchParam, this._formHistoryResult, this);
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * Makes a note of the fact that we've received a backoff-triggering
michael@0:    * response, so that we can adjust the backoff behavior appropriately.
michael@0:    */
michael@0:   _noteServerError: function SAC__noteServeError() {
michael@0:     var currentTime = Date.now();
michael@0: 
michael@0:     this._serverErrorLog.push(currentTime);
michael@0:     if (this._serverErrorLog.length > this._maxErrorsBeforeBackoff)
michael@0:       this._serverErrorLog.shift();
michael@0: 
michael@0:     if ((this._serverErrorLog.length == this._maxErrorsBeforeBackoff) &&
michael@0:         ((currentTime - this._serverErrorLog[0]) < this._serverErrorPeriod)) {
michael@0:       // increase timeout, and then don't request until timeout is over
michael@0:       this._serverErrorTimeout = (this._serverErrorTimeout * 2) +
michael@0:                                  this._serverErrorTimeoutIncrement;
michael@0:       this._nextRequestTime = currentTime + this._serverErrorTimeout;
michael@0:     }
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * Resets the backoff behavior; called when we get a successful response.
michael@0:    */
michael@0:   _clearServerErrors: function SAC__clearServerErrors() {
michael@0:     this._serverErrorLog = [];
michael@0:     this._serverErrorTimeout = 0;
michael@0:     this._nextRequestTime = 0;
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * This checks whether we should send a server request (i.e. we're not
michael@0:    * in a error-triggered backoff period.
michael@0:    *
michael@0:    * @private
michael@0:    */
michael@0:   _okToRequest: function SAC__okToRequest() {
michael@0:     return Date.now() > this._nextRequestTime;
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * This checks to see if the new search engine is different
michael@0:    * from the previous one, and if so clears any error state that might
michael@0:    * have accumulated for the old engine.
michael@0:    *
michael@0:    * @param engine The engine that the suggestion request would be sent to.
michael@0:    * @private
michael@0:    */
michael@0:   _checkForEngineSwitch: function SAC__checkForEngineSwitch(engine) {
michael@0:     if (engine == this._serverErrorEngine)
michael@0:       return;
michael@0: 
michael@0:     // must've switched search providers, clear old errors
michael@0:     this._serverErrorEngine = engine;
michael@0:     this._clearServerErrors();
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * This returns true if the status code of the HTTP response
michael@0:    * represents a backoff-triggering error.
michael@0:    *
michael@0:    * @param status  The status code from the HTTP response
michael@0:    * @private
michael@0:    */
michael@0:   _isBackoffError: function SAC__isBackoffError(status) {
michael@0:     return ((status == HTTP_INTERNAL_SERVER_ERROR) ||
michael@0:             (status == HTTP_BAD_GATEWAY) ||
michael@0:             (status == HTTP_SERVICE_UNAVAILABLE));
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * Called when the 'readyState' of the XMLHttpRequest changes. We only care
michael@0:    * about state 4 (COMPLETED) - handle the response data.
michael@0:    * @private
michael@0:    */
michael@0:   onReadyStateChange: function() {
michael@0:     // xxx use the real const here
michael@0:     if (!this._request || this._request.readyState != 4)
michael@0:       return;
michael@0: 
michael@0:     try {
michael@0:       var status = this._request.status;
michael@0:     } catch (e) {
michael@0:       // The XML HttpRequest can throw NS_ERROR_NOT_AVAILABLE.
michael@0:       return;
michael@0:     }
michael@0: 
michael@0:     if (this._isBackoffError(status)) {
michael@0:       this._noteServerError();
michael@0:       return;
michael@0:     }
michael@0: 
michael@0:     var responseText = this._request.responseText;
michael@0:     if (status != HTTP_OK || responseText == "")
michael@0:       return;
michael@0: 
michael@0:     this._clearServerErrors();
michael@0: 
michael@0:     try {
michael@0:       var serverResults = JSON.parse(responseText);
michael@0:     } catch(ex) {
michael@0:       Components.utils.reportError("Failed to parse JSON from " + this._suggestURI.spec + ": " + ex);
michael@0:       return;
michael@0:     }
michael@0: 
michael@0:     var searchString = serverResults[0] || "";
michael@0:     var results = serverResults[1] || [];
michael@0: 
michael@0:     var comments = [];  // "comments" column values for suggestions
michael@0:     var historyResults = [];
michael@0:     var historyComments = [];
michael@0: 
michael@0:     // If form history is enabled and has results, add them to the list.
michael@0:     if (this._includeFormHistory && this._formHistoryResult &&
michael@0:         (this._formHistoryResult.searchResult ==
michael@0:          Ci.nsIAutoCompleteResult.RESULT_SUCCESS)) {
michael@0:       var maxHistoryItems = Math.min(this._formHistoryResult.matchCount, this._historyLimit);
michael@0:       for (var i = 0; i < maxHistoryItems; ++i) {
michael@0:         var term = this._formHistoryResult.getValueAt(i);
michael@0: 
michael@0:         // we don't want things to appear in both history and suggestions
michael@0:         var dupIndex = results.indexOf(term);
michael@0:         if (dupIndex != -1)
michael@0:           results.splice(dupIndex, 1);
michael@0: 
michael@0:         historyResults.push(term);
michael@0:         historyComments.push("");
michael@0:       }
michael@0:     }
michael@0: 
michael@0:     // fill out the comment column for the suggestions
michael@0:     for (var i = 0; i < results.length; ++i)
michael@0:       comments.push("");
michael@0: 
michael@0:     // if we have any suggestions, put a label at the top
michael@0:     if (comments.length > 0)
michael@0:       comments[0] = this._suggestionLabel;
michael@0: 
michael@0:     // now put the history results above the suggestions
michael@0:     var finalResults = historyResults.concat(results);
michael@0:     var finalComments = historyComments.concat(comments);
michael@0: 
michael@0:     // Notify the FE of our new results
michael@0:     this.onResultsReady(searchString, finalResults, finalComments,
michael@0:                         this._formHistoryResult);
michael@0: 
michael@0:     // Reset our state for next time.
michael@0:     this._reset();
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * Notifies the front end of new results.
michael@0:    * @param searchString  the user's query string
michael@0:    * @param results       an array of results to the search
michael@0:    * @param comments      an array of metadata corresponding to the results
michael@0:    * @private
michael@0:    */
michael@0:   onResultsReady: function(searchString, results, comments,
michael@0:                            formHistoryResult) {
michael@0:     if (this._listener) {
michael@0:       var result = new FormAutoCompleteResult(
michael@0:           searchString,
michael@0:           Ci.nsIAutoCompleteResult.RESULT_SUCCESS,
michael@0:           0,
michael@0:           "",
michael@0:           results,
michael@0:           results,
michael@0:           comments,
michael@0:           formHistoryResult);
michael@0: 
michael@0:       this._listener.onSearchResult(this, result);
michael@0: 
michael@0:       // Null out listener to make sure we don't notify it twice, in case our
michael@0:       // timer callback still hasn't run.
michael@0:       this._listener = null;
michael@0:     }
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * Initiates the search result gathering process. Part of
michael@0:    * nsIAutoCompleteSearch implementation.
michael@0:    *
michael@0:    * @param searchString    the user's query string
michael@0:    * @param searchParam     unused, "an extra parameter"; even though
michael@0:    *                        this parameter and the next are unused, pass
michael@0:    *                        them through in case the form history
michael@0:    *                        service wants them
michael@0:    * @param previousResult  unused, a client-cached store of the previous
michael@0:    *                        generated resultset for faster searching.
michael@0:    * @param listener        object implementing nsIAutoCompleteObserver which
michael@0:    *                        we notify when results are ready.
michael@0:    */
michael@0:   startSearch: function(searchString, searchParam, previousResult, listener) {
michael@0:     // Don't reuse a previous form history result when it no longer applies.
michael@0:     if (!previousResult)
michael@0:       this._formHistoryResult = null;
michael@0: 
michael@0:     var formHistorySearchParam = searchParam.split("|")[0];
michael@0: 
michael@0:     // Receive the information about the privacy mode of the window to which
michael@0:     // this search box belongs.  The front-end's search.xml bindings passes this
michael@0:     // information in the searchParam parameter.  The alternative would have
michael@0:     // been to modify nsIAutoCompleteSearch to add an argument to startSearch
michael@0:     // and patch all of autocomplete to be aware of this, but the searchParam
michael@0:     // argument is already an opaque argument, so this solution is hopefully
michael@0:     // less hackish (although still gross.)
michael@0:     var privacyMode = (searchParam.split("|")[1] == "private");
michael@0: 
michael@0:     // Start search immediately if possible, otherwise once the search
michael@0:     // service is initialized
michael@0:     if (Services.search.isInitialized) {
michael@0:       this._triggerSearch(searchString, formHistorySearchParam, listener, privacyMode);
michael@0:       return;
michael@0:     }
michael@0: 
michael@0:     Services.search.init((function startSearch_cb(aResult) {
michael@0:       if (!Components.isSuccessCode(aResult)) {
michael@0:         Cu.reportError("Could not initialize search service, bailing out: " + aResult);
michael@0:         return;
michael@0:       }
michael@0:       this._triggerSearch(searchString, formHistorySearchParam, listener, privacyMode);
michael@0:     }).bind(this));
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * Actual implementation of search.
michael@0:    */
michael@0:   _triggerSearch: function(searchString, searchParam, listener, privacyMode) {
michael@0:     // If there's an existing request, stop it. There is no smart filtering
michael@0:     // here as there is when looking through history/form data because the
michael@0:     // result set returned by the server is different for every typed value -
michael@0:     // "ocean breathes" does not return a subset of the results returned for
michael@0:     // "ocean", for example. This does nothing if there is no current request.
michael@0:     this.stopSearch();
michael@0: 
michael@0:     this._listener = listener;
michael@0: 
michael@0:     var engine = Services.search.currentEngine;
michael@0: 
michael@0:     this._checkForEngineSwitch(engine);
michael@0: 
michael@0:     if (!searchString ||
michael@0:         !this._suggestEnabled ||
michael@0:         !engine.supportsResponseType(SEARCH_RESPONSE_SUGGESTION_JSON) ||
michael@0:         !this._okToRequest()) {
michael@0:       // We have an empty search string (user pressed down arrow to see
michael@0:       // history), or search suggestions are disabled, or the current engine
michael@0:       // has no suggest functionality, or we're in backoff mode; so just use
michael@0:       // local history.
michael@0:       this._sentSuggestRequest = false;
michael@0:       this._startHistorySearch(searchString, searchParam);
michael@0:       return;
michael@0:     }
michael@0: 
michael@0:     // Actually do the search
michael@0:     this._request = Cc["@mozilla.org/xmlextras/xmlhttprequest;1"].
michael@0:                     createInstance(Ci.nsIXMLHttpRequest);
michael@0:     var submission = engine.getSubmission(searchString,
michael@0:                                           SEARCH_RESPONSE_SUGGESTION_JSON);
michael@0:     this._suggestURI = submission.uri;
michael@0:     var method = (submission.postData ? "POST" : "GET");
michael@0:     this._request.open(method, this._suggestURI.spec, true);
michael@0:     this._request.channel.notificationCallbacks = new AuthPromptOverride();
michael@0:     if (this._request.channel instanceof Ci.nsIPrivateBrowsingChannel) {
michael@0:       this._request.channel.setPrivate(privacyMode);
michael@0:     }
michael@0: 
michael@0:     var self = this;
michael@0:     function onReadyStateChange() {
michael@0:       self.onReadyStateChange();
michael@0:     }
michael@0:     this._request.onreadystatechange = onReadyStateChange;
michael@0:     this._request.send(submission.postData);
michael@0: 
michael@0:     if (this._includeFormHistory) {
michael@0:       this._sentSuggestRequest = true;
michael@0:       this._startHistorySearch(searchString, searchParam);
michael@0:     }
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * Ends the search result gathering process. Part of nsIAutoCompleteSearch
michael@0:    * implementation.
michael@0:    */
michael@0:   stopSearch: function() {
michael@0:     if (this._request) {
michael@0:       this._request.abort();
michael@0:       this._reset();
michael@0:     }
michael@0:   },
michael@0: 
michael@0:   /**
michael@0:    * nsIObserver
michael@0:    */
michael@0:   observe: function SAC_observe(aSubject, aTopic, aData) {
michael@0:     switch (aTopic) {
michael@0:       case NS_PREFBRANCH_PREFCHANGE_TOPIC_ID:
michael@0:         this._suggestEnabled = Services.prefs.getBoolPref(BROWSER_SUGGEST_PREF);
michael@0:         break;
michael@0:       case XPCOM_SHUTDOWN_TOPIC:
michael@0:         this._removeObservers();
michael@0:         break;
michael@0:     }
michael@0:   },
michael@0: 
michael@0:   _addObservers: function SAC_addObservers() {
michael@0:     Services.prefs.addObserver(BROWSER_SUGGEST_PREF, this, false);
michael@0: 
michael@0:     Services.obs.addObserver(this, XPCOM_SHUTDOWN_TOPIC, false);
michael@0:   },
michael@0: 
michael@0:   _removeObservers: function SAC_removeObservers() {
michael@0:     Services.prefs.removeObserver(BROWSER_SUGGEST_PREF, this);
michael@0: 
michael@0:     Services.obs.removeObserver(this, XPCOM_SHUTDOWN_TOPIC);
michael@0:   },
michael@0: 
michael@0:   // nsISupports
michael@0:   QueryInterface: XPCOMUtils.generateQI([Ci.nsIAutoCompleteSearch,
michael@0:                                          Ci.nsIAutoCompleteObserver])
michael@0: };
michael@0: 
michael@0: function AuthPromptOverride() {
michael@0: }
michael@0: AuthPromptOverride.prototype = {
michael@0:   // nsIAuthPromptProvider
michael@0:   getAuthPrompt: function (reason, iid) {
michael@0:     // Return a no-op nsIAuthPrompt2 implementation.
michael@0:     return {
michael@0:       promptAuth: function () {
michael@0:         throw Cr.NS_ERROR_NOT_IMPLEMENTED;
michael@0:       },
michael@0:       asyncPromptAuth: function () {
michael@0:         throw Cr.NS_ERROR_NOT_IMPLEMENTED;
michael@0:       }
michael@0:     };
michael@0:   },
michael@0: 
michael@0:   // nsIInterfaceRequestor
michael@0:   getInterface: function SSLL_getInterface(iid) {
michael@0:     return this.QueryInterface(iid);
michael@0:   },
michael@0: 
michael@0:   // nsISupports
michael@0:   QueryInterface: XPCOMUtils.generateQI([Ci.nsIAuthPromptProvider,
michael@0:                                          Ci.nsIInterfaceRequestor])
michael@0: };
michael@0: /**
michael@0:  * SearchSuggestAutoComplete is a service implementation that handles suggest
michael@0:  * results specific to web searches.
michael@0:  * @constructor
michael@0:  */
michael@0: function SearchSuggestAutoComplete() {
michael@0:   // This calls _init() in the parent class (SuggestAutoComplete) via the
michael@0:   // prototype, below.
michael@0:   this._init();
michael@0: }
michael@0: SearchSuggestAutoComplete.prototype = {
michael@0:   classID: Components.ID("{aa892eb4-ffbf-477d-9f9a-06c995ae9f27}"),
michael@0:   __proto__: SuggestAutoComplete.prototype,
michael@0:   serviceURL: ""
michael@0: };
michael@0: 
michael@0: var component = [SearchSuggestAutoComplete];
michael@0: this.NSGetFactory = XPCOMUtils.generateNSGetFactory(component);