WKWebView: localStorage becomes null on window.close - wkwebview

I have some 3rd-party content in a WKWebView that tries to read from localStorage on window-close. WKWebView doesn't trigger any events on window.close, so I'm doing it myself in the webViewDidClose delegate method.
The problem is that as soon as window.close() is executed, localStorage becomes null! This does not happen in a desktop browser window. Interestingly, only localStorage is lost, sessionStorage remains accessible.
In Safari inspector console:
onunload=function() {
debugger;
// localStorage is null
// sessionStorage is Storage
}
close();
On the native side:
func webViewDidClose(_ webView: WKWebView) {
// Trigger the unload event before closing the web view
webView.evaluateJavaScript("dispatchEvent(new Event('unload'));")
// Give the content some time to respond to the event, and then destroy the web view
DispatchQueue.main.asyncAfter(deadline: .now() + .milliseconds(500)) {
self.webView?.removeFromSuperview();
self.webView = nil
}
}

Related

load last viewed page on chrome extension startup

I'm developing my first chrome extension and I'm stuck with a "session restore" problem. At the begging of the developement when a user log in to my extension and close the popup, when he open the plugin again he had to login again.
I've used chrome.storage.sync to be able to save the session infomation to make the user to be still logged in and if he close the plugin, and his session is still active he will be redirected to the welcome page. But how can I check at the extension's startup in what page of the plugin the user was and bring him back to that page?
For example, if a user is logged and was on the "choose a book" section, how can i make the plugin open at "choose a book" section and not in "welcome" section?
Angular 2 for client side
NodeJs for server side
Consider that the session object is something like:
{
logged: true,
last_section: 'books'
}
When the user visits the books section, save it.
// this code goes inside some listener for visiting a section
chrome.storage.sync.get('session', function (items) {
const session = items.session || {}
session.last_section = 'books'
chrome.storage.sync.set({ session })
})
At the beginning of the popup script, you can simply call chrome.storage.sync.get to get the last session object state.
chrome.storage.sync.get('session', function (items) {
const session = items.session
if (session && session.logged) {
if (session.last_section === 'books') {
// render books section
}
if (session.last_section === 'welcome') {
// render welcome section
}
}
})

Handle OAuth callback in node-webkit

I'm working on GitHub APIs and want to store returned access_token into localStorage in node-webkit.
So, the question is, how to fetch the token from a remote(HTTP) callback URL like http://localhost:2222/github-callback?code=somecodehere?
Open authorization page in a new window
var authWindow = gui.Window.open("https://github.com/login/oauth/authorize");
Have a listener on its loaded event
authWindow.on('loaded', function() {
if(authWindow.location.href.substr(0, 34) === "http://your.domain/github-callback") {
// do what you want
}
// maybe some cleanup
}

Firefox Extension Development

In Chrome Extension Development we have Background Page Concepts. Is any thing similar available in Firefox Extension Development also. While Developing Chrome Extensions I have seen methods like
window.Bkg = chrome.extension.getBackgroundPage().Bkg;
$(function () {
var view = null;
if (Bkg.account.isLoggedIn()) {
view = new Views.Popup();
$("#content").append(view.render().el);
} else {
$("#content").append(Template('logged_out')());
Bkg.refresh();
}
}...........
Where the main logic are written in Background Page(like isLoggedIn etc) and from the Extension Popup page we are calling Background page. Here for instance the background page is always loaded which manages the session. How can we have similar functionality in Firefox Extension Development.
All communication between the background page (main.js) and content scripts (your popup script) occurs via events. You cannot call functions immediately, so you won't receive any return values, but you can send an event from a content script to the background script that sends an event back to the content script and calls a new function, like so:
main.js partial
// See docs below on how to create a panel/popup
panel.port.on('loggedIn', function(message) {
panel.port.emit('isLoggedIn', someBoolean);
});
panel.port.on('refresh', function() {
// do something to refresh the view
});
popup.js
var view = null;
addon.port.on('isLoggedIn', function(someBool) {
if (someBool) {
// Obviously not code that's going to work in FF, just want you to know how to structure
view = new Views.Popup();
$("#content").append(view.render().el);
} else {
$("#content").append(Template('logged_out')());
addon.port.emit('refresh');
}
});
addon.port.emit('loggedIn', 'This is a message. I can pass any var along with the event, but I don't have to');
You should read this stuff:
Panel
Communicating between scripts

Chrome/FF/Safari extension: Load hidden web page in incognito-like mode

Is it possible to build an 'incognito mode' for loading background web-pages in a browser extension?
I am writing a non-IE cross-browser extension that periodically checks web-pages on the user's behalf. There are two requirements:
Page checks are done in the background, to be as unobtrusive as possible. I believe this could be done by opening the page in a new unfocussed browser tab, or hidden in a sandboxed iframe in the extension's background page.
The page checks should operate in 'incognito mode', and not use/update the user's cookies, history, or local storage. This is to stop the checks polluting the user's actual browsing behavior as much as possible.
Any thoughts on how to implement this 'incognito mode'?
It would ideally work in as many browser types as possible (not IE).
My current ideas are:
Filter out cookie headers from incoming/outgoing http requests associated with the page checks (if I can identify all of these) (not possible in Safari?)
After each page check, filter out the page from the user's history.
Useful SO questions I've found:
Chrome extension: loading a hidden page (without iframe)
Firefox addon development, open a hidden web browser
Identify requests originating in the hiddenDOMWindow (or one of its iframes)
var Cu = Components.utils;
Cu.import('resource://gre/modules/Services.jsm');
Cu.import('resource://gre/modules/devtools/Console.jsm');
var win = Services.appShell.hiddenDOMWindow
var iframe = win.document.createElementNS('http://www.w3.org/1999/xhtml', 'iframe');
iframe.addEventListener('DOMContentLoaded', function(e) {
var win = e.originalTarget.defaultView;
console.log('done loaded', e.document.location);
if (win.frameElement && win.frameElement != iframe) {
//its a frame in the in iframe that load
}
}, false);
win.document.documentElement.appendChild(iframe);
must keep a global var reference to iframe we added.
then you can change the iframe location like this, and when its loaded it triggers the event listener above
iframe.contentWindow.location = 'http://www.bing.com/'
that DOMContentLoaded identifies all things loaded in that iframe. if the page has frames it detects that too.
to remove from history, into the DOMContentLoaded function use the history service to remove win.location from history:
https://developer.mozilla.org/en-US/docs/Using_the_Places_history_service
now to strip the cookies from requests in that page use this code:
const {classes: Cc, Constructor: CC, interfaces: Ci, utils: Cu, results: Cr, manager: Cm} = Components;
Cu.import('resource://gre/modules/Services.jsm');
var myTabToSpoofIn = Services.wm.getMostRecentBrowser('navigator:browser').gBrowser.tabContainer[0]; //will spoof in the first tab of your browser
var httpRequestObserver = {
observe: function (subject, topic, data) {
var httpChannel, requestURL;
if (topic == "http-on-modify-request") {
httpChannel = subject.QueryInterface(Ci.nsIHttpChannel);
var goodies = loadContextGoodies(httpChannel)
if (goodies) {
if (goodies.contentWindow.top == iframe.contentWindow.top) {
httpChannel.setRequestHeader('Cookie', '', false);
} else {
//this page load isnt in our iframe so ignore it
}
}
}
}
};
Services.obs.addObserver(httpRequestObserver, "http-on-modify-request", false);
//Services.obs.removeObserver(httpRequestObserver, "http-on-modify-request", false); //run this on shudown of your addon otherwise the observer stags registerd
//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';
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
}

Message isn't passed between background.html and popup.html

I'm trying to pass data that is saved in sessionStorage from background.html to popup.html
background.html:
chrome.extension.onRequest.addListener(function(request, sender, sendResponse) {
data = sessionStorage.getItem(request.tabId);
alert(data);
sendResponse({ data: data });
});
and in popup.html:
chrome.tabs.getSelected(null, function(tab) {
chrome.extension.sendRequest({ tabId: tab.id }, function(response) {
alert(response.data);
});
});
The popup is opened by a pageAction button, when I click the button I get an alert box with "null" on the popup and then an alert box with the data that I stored in sessionStorage on the background!
Any ideas how to fix this?
You don't need to use message/request APIs. I think this response may help you.
You also don't need sessionStorage, just store your data in a global variable of the background page. It will persist until the browser is closed or until the extension is restarted.
So, here is how I would rewrite your code:
background.html:
var data = {}; // Object storing data indexed by tab id
and in popup.html:
chrome.tabs.getSelected(null, function(tab) {
alert(chrome.extension.getBackgroundPage().data[tab.id]);
});
Note that chrome.tabs.getSelected is deprecated since Chrome 16, so popup code should be:
chrome.windows.getCurrent(function(win) {
chrome.tabs.query({'windowId': win.id, 'active': true}, function(tabArray) {
alert(chrome.extension.getBackgroundPage().data[tabArray[0].id]);
});
});
Well, I've done something dumb.
I inspected the background page by opening chrome-extension://[extension-id]/background.html in a tab instead of clicking on "inspect active views: background.html" in the extensions management page. This caused the tab to catch the request and call sendResponse, but the popup expected the REAL background page to call sendResponse (and if I understand Google's documentation regarding message passing, the fact that sendResponse was called twice is root of the problem, because the first call clears the request object)

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