Firefox SDK: How to make trigger for certain domain - firefox-addon

Question

I need to catch requests on sites with URLs *.net and take some actions (stop request and put HTML code from disk, but this I can do). How do I catch these requests?
I tried to use progress listeners, but something is 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 nsIHTTPChannel and observer service. copy paste it. however .net can be included in resources like javascript things, if you want to test if its specfically a window you have to check for some load flags of LOAD_INITIAL_DOCUMENT_URI, also will want to 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
}