Firefox SDK: how to make a trigger for a specific domain

Question

I need to catch requests on sites with URLs *. net and take some action (stop the request and put the HTML code from disk, but I can do this). How to catch these requests?

I tried to use progressive listeners, but something was wrong:

const STATE_START = Ci.nsIWebProgressListener.STATE_START;

var myListener = {
    QueryInterface: XPCOMUtils.generateQI(["nsIWebProgressListener",
                                       "nsISupportsWeakReference"]),

    onStateChange: function(aWebProgress, aRequest, aFlag, aStatus) {
        if (aFlag & STATE_START) {
            // actions
        }
    }

Answer 1

use the nsIHTTPChannel and observer service. copy it. however .net can be included in resources such as javascript, if you want to check if its specfically there will be a window that you should check for some load flags LOAD_INITIAL_DOCUMENT_URI, also want chec

Cu.import('resource://gre/modules/Services.jsm');

var httpRequestObserver = {
    observe: function (subject, topic, data) {
        var httpChannel, requestURL;

        if (topic == "http-on-modify-request") {
            httpChannel = subject.QueryInterface(Ci.nsIHttpChannel);
            requestURL = httpChannel.URI.spec;

            var newRequestURL, i;
            if (httpChannel.loadFlags & httpChannel.LOAD_INITIAL_DOCUMENT_URI) {
                //ok continue because loadFlags is a document
            } else {
                //its not a document, probably a resource like a js file image or css or something, but maybe could be ajax call
                return;
            }
            if (requestURL.indexOf('.net')) {
                var goodies = loadContextGoodies(httpChannel);
                if (goodies) {
                    httpChannel.cancel(Cr.NS_BINDING_ABORTED);
                    goodies.contentWindow.location = self.data.url('pages/test.html');
                } else {
                    //dont do anything as there is no contentWindow associated with the httpChannel, liekly a google ad is loading or some ajax call or something, so this is not an error
                }
            }

            return;
        }
    }
};
Services.obs.addObserver(httpRequestObserver, "http-on-modify-request", false);


















 //this function gets the contentWindow and other good stuff from loadContext of httpChannel
function loadContextGoodies(httpChannel) {
    //httpChannel must be the subject of http-on-modify-request QI'ed to nsiHTTPChannel as is done on line 8 "httpChannel = subject.QueryInterface(Ci.nsIHttpChannel);"
    //start loadContext stuff
    var loadContext;
    try {
        var interfaceRequestor = httpChannel.notificationCallbacks.QueryInterface(Ci.nsIInterfaceRequestor);
        //var DOMWindow = interfaceRequestor.getInterface(Components.interfaces.nsIDOMWindow); //not to be done anymore because: https://developer.mozilla.org/en-US/docs/Updating_extensions_for_Firefox_3.5#Getting_a_load_context_from_a_request //instead do the loadContext stuff below
        try {
            loadContext = interfaceRequestor.getInterface(Ci.nsILoadContext);
        } catch (ex) {
            try {
                loadContext = subject.loadGroup.notificationCallbacks.getInterface(Ci.nsILoadContext);
            } catch (ex2) {}
        }
    } catch (ex0) {}

    if (!loadContext) {
        //no load context so dont do anything although you can run this, which is your old code
        //this probably means that its loading an ajax call or like a google ad thing
        return null;
    } else {
        var contentWindow = loadContext.associatedWindow;
        if (!contentWindow) {
            //this channel does not have a window, its probably loading a resource
            //this probably means that its loading an ajax call or like a google ad thing
            return null;
        } else {
            var aDOMWindow = contentWindow.top.QueryInterface(Ci.nsIInterfaceRequestor)
                .getInterface(Ci.nsIWebNavigation)
                .QueryInterface(Ci.nsIDocShellTreeItem)
                .rootTreeItem
                .QueryInterface(Ci.nsIInterfaceRequestor)
                .getInterface(Ci.nsIDOMWindow);
            var gBrowser = aDOMWindow.gBrowser;
            var aTab = gBrowser._getTabForContentWindow(contentWindow.top); //this is the clickable tab xul element, the one found in the tab strip of the firefox window, aTab.linkedBrowser is same as browser var above //can stylize tab like aTab.style.backgroundColor = 'blue'; //can stylize the tab like aTab.style.fontColor = 'red';
            if (aTab == null) {
                return null;
            }
            else {
                var browser = aTab.linkedBrowser; //this is the browser within the tab //this is where the example in the previous section ends
                return {
                    aDOMWindow: aDOMWindow,
                    gBrowser: gBrowser,
                    aTab: aTab,
                    browser: browser,
                    contentWindow: contentWindow
                };
            }
    }
    //end loadContext stuff
}