This is probably more of a general c# and simple threading question than it is a Facebook SDK question, but I may be wrong. But I could really use some help. I am reusing the sample code that comes with the SDK which includes a FacebookLoginDialog class. I am currently using it like this. In my GetMessages, GetFriendRequests, and other Get* classes, I always try/catch calls like this:
try
{
var result = (IDictionary<string, object>)fb.Get("/me/inbox");
}
catch (FacebookOAuthException e)
{
FacebookSession.Login();
}
Here's my login method in my FacebookSession class
public static void Login()
{
var fbLoginDialog = new FacebookLoginDialog(APP_ID, EXTENDED_PERMISSIONS);
DialogResult dr = fbLoginDialog.ShowDialog();
DisplayAppropriateMessage(fbLoginDialog.FacebookOAuthResult);
}
And here is the constructor in my FacebookLoginDialog class (this is where I have the problem)
public FacebookLoginDialog(string appId, string[] extendedPermissions, bool logout)
{
try
{
var oauth = new FacebookOAuthClient { AppId = appId };
var loginParameters = new Dictionary<string, object>
{
{ "response_type", "token" },
{ "display", "popup" }
};
if (extendedPermissions != null && extendedPermissions.Length > 0)
{
var scope = new StringBuilder();
scope.Append(string.Join(",", extendedPermissions));
loginParameters["scope"] = scope.ToString();
}
var loginUrl = oauth.GetLoginUrl(loginParameters);
if (logout)
{
var logoutParameters = new Dictionary<string, object>
{
{ "next", loginUrl }
};
System.Uri uri =
new Uri("https://www.facebook.com/logout.php?next=" +
"https://www.facebook.com/connect/login_success.html&access_token=" +
FacebookSession._accessToken);
this.navigateUrl = uri;
}
else
{
this.navigateUrl = loginUrl;
}
InitializeComponent(); // crash here... sometimes
}
catch (Exception e)
{
//Log error message
}
}
Sorry for all the code, but now the problem. This code works fine the first time through. If I go to my facebook applications permissions page in Facebook and remove the app (that is, remove its permissions), while my desktop app here is NOT running, when I do start it up, it sees that it does not have permission and shows the login dialog. I can save the access_key and it will work just fine. But if I go to the facebook apps page and yank the permissions while my desktop app is running, then bad things happen. I get an error message about the activex control cannot be instantiated because the current thread is not in a single-threaded apartment. I have seen many posts here that say all you have to do is put [STAThread] above your main(), and my code has that. I have also tried creating a new thread to call the FacebookLoginDialog, but not only did that not work, but since my code is really not designed to run in multiple threads, that started causing more problems.
Is there a simple solution to all this, or do I need to redesign my code so that it properly runs in multiple threads? Or should I just live with the program crashing in those few instances when someone monkeys with the facebook permissions while my app is running?
Related
I'm trying to access the ContactStore of MacOS App, did the following implementation
public void Contacts()
{
//Starting
var store = new CNContactStore();
store.RequestAccess(CNEntityType.Contacts, async (bool granted, NSError error) =>
{
if (granted)
{
//Query things
}
});
}
The thing is that the Authorize screen never popup, and the Permission always say denied.
If I go to settings to remove that record, the app is not there.
Can someone please point me to the light?
It works for me with those two lines:
var contactStore = new CNContactStore();
var status = CNContactStore.GetAuthorizationStatus(CNEntityType.Contacts);
It could be also that you need to set NSContactsUsageDescription in info.plist.
I am using GeckoFx to perform a login to a specific website. This website edits the page with new information should the login fail (or require additional authentication, such as a ReCaptcha). Unfortunately, it is vital that I have access an event when the page is updated. I have tried numerous approaches mainly
A continual check if the uri is still the same upon each login attempt and a subsequent check on the specific element in question (to see if the display: none property was changed. (This resulted in an infinite loop as it seems GeckoFx updates the page in a nonblocking way, causing the program to go into an infinite loop)
Sleeping for ~5 seconds between login requests and using the aforementioned uri check. All this did (predictably, I was grasping at straws) was freeze the browser for 5 seconds and still fail to update the page
Searching the GeckoFx codebase for a specific event when the page is updated similar to the DocumentCompleted event (no such luck).
The most common approach I have read about (and one that makes the most sense) is to use a MutationObserver. It seems that all of the answers across the internet involve injecting Javascript in order to perform the requisite task. Seeing as all of my programming background has not touched web development whatsoever, I'm trying to stick to what I know.
Here is my approach so far, unfortunately, it is not much.
public class GeckoTestWebLogin
{
private readonly string _user;
private readonly string _pass;
public GeckoWebBrowser Gweb;
public Uri LoginUri { get; } = new Uri("https://website.com/login/");
public bool LoginCompleted { get; private set; } = false;
public bool Loaded { get; private set; } = false;
public GeckoTestWebLogin(string user, string pass)
{
_user = user;
_pass = pass;
Xpcom.EnableProfileMonitoring = false;
Xpcom.Initialize("Firefox");
//this code is for testing purposes, it will be removed upon project completion
CookieManager.RemoveAll();
Gweb = new GeckoWebBrowser();
Gweb.DocumentCompleted += DocLoaded;
//right about here is where I get lost, where can I set a callback method for the observer to report back to? Is this even how it works?
MutationObserver mutationObserver = new MutationObserver(Gweb.Window.DomWindow, (nsISupports)Gweb.Document.DomObject);
}
private void TestObservedEvent(string parms, object[] objs)
{
MessageBox.Show("The page was changed # " + DateTime.Now);
}
public void DocLoaded(object obj, GeckoDocumentCompletedEventArgs e)
{
Loaded = true;
if (Gweb.Url != LoginUri) return;
AttemptLogin();
}
private void AttemptLogin()
{
GeckoElementCollection elements = Gweb.Document.GetElementsByTagName("input");
foreach (GeckoHtmlElement element in elements)
{
switch (element.Id)
{
case "username":
element.SetAttribute("value", _user);
break;
case "password":
element.SetAttribute("value", _pass);
break;
case "importantchangedinfo":
GeckoHtmlElement authcodeModal =
(GeckoHtmlElement)
Gweb.Document.GetElementsByClassName("login_modal").First();
if (authcodeModal.Attributes["style"].NodeValue != "display: none")
{
InputForm form = new InputForm { InputDescription = "Captcha Required!" };
form.ShowDialog();
elements.FirstOrDefault(x => x.Id == "captchabox")?.SetAttribute("value", form.Input);
}
break;
}
}
elements.FirstOrDefault(x => x.Id == "Login")?.Click();
}
public void Login()
{
//this will cause the DocLoaded event to fire after completion
Gweb.Navigate(LoginUri.ToString());
}
}
As stated in the above code in the comments, I am completely lost at
MutationObserver mutationObserver = new MutationObserver(Gweb.Window.DomWindow, (nsISupports)Gweb.Document.DomObject);
I can't seem to find anything in GeckoFx's source for MutationObserver that would allow me to set a callback/event/whathaveyou. Is my approach the correct way to go about things or am I left with no options other than to inject Javascript into the page?
Much appreciated, thank you in advance.
Here is my attempt at option 2 in Tom's answer:
(Added into GeckoTestWebLogin)
public void DocLoaded(object obj, GeckoDocumentCompletedEventArgs e)
{
Loaded = true;
if (Gweb.Url != LoginUri) return;
MutationEventListener mutationListener = new MutationEventListener();
mutationListener.OnDomMutation += TestObservedEvent;
nsIDOMEventTarget target = Xpcom.QueryInterface<nsIDOMEventTarget>(/*Lost here*/);
using (nsAString modified = new nsAString("DOMSubtreeModified"))
target.AddEventListener(modified, mutationListener, true, false, 0);
AttemptLogin();
}
MutationEventListener.cs:
public delegate void OnDomMutation(/*DomMutationArgs args*/);
public class MutationEventListener : nsIDOMEventListener
{
public event OnDomMutation OnDomMutation;
public void HandleEvent(nsIDOMEvent domEvent)
{
OnDomMutation?.Invoke(/*new DomMutationArgs(domEvent, this)*/);
}
}
I don't think Geckofx's webidl compiler is currently advanced enough to generate the callback constructor.
Option 1. - Enhance MutationObserver source.
You could modify MutationObserver source manually to add the necessary constructor callback. Then recompile Geckofx. (I haven't look to see how difficult this is)
Option 2. - Use old style Mutation events.
public class DOMSubtreeModifiedEventListener : nsIDOMEventListener
{
... // Implement HandleEvent
}
Then something like (maybe in DocumentCompleted event handler):
_domSubtreeModifiedEventListener = new DOMSubtreeModifiedEventListener(this);
var target = Xpcom.QueryInterface<nsIDOMEventTarget>(body);
using (nsAString subtreeModified = new nsAString("DOMSubtreeModified"))
target.AddEventListener(subtreeModified, _domSubtreeModifiedEventListener, true, false, 0);
Option 3. - Use Idle + Check.
Add an winforms Application.idle event handler - and examine the document, to know when its ready.
Option 4. - Inject a javascript callback.
(As you have already mentioned) - This example is waiting until after a resize is done.
basically inject: "<body onresize=fireResizedEventAfterDelay()>" : then inject something like this:
string fireResizedEventAfterDelayScript = "<script>\n" +
"var resizeListner;" +
"var msDelay = 20;" +
"function fireResizedEventAfterDelay() {" +
"clearTimeout(resizeListner);" +
"resizeListner = setTimeout(function() { document.dispatchEvent (new MessageEvent('resized')); }, msDelay);" +
"}\n" +
"</script>\n";
Then in the C#:
browser.AddMessageEventListener("resized", (s) => runafterImDone())
The Situation
I'm working on a OAuth2 Api Wrapper. Some api routes are for logged people and some for anonymous and logged.
Here is an example of one method in my wrapper :
public async Task<UploadListResponse> List(bool pagination = false, int page = 1, int limit = 10)
{
var request = UploadRequests.List(pagination, page, limit);
var cancellationTokenSource = new CancellationTokenSource();
var restResponse = await Context.Client.ExecuteTaskAsync(request, cancellationTokenSource.Token);
return restResponse.Handle<UploadListResponse>();
}
I build a request with all parameter set up then execute the request and then handle the answer in case I have an api error and then output an object containing all the data that request gave me.
The problem
With OAuth2, when you log to the API you'll receive an access token and a refresh token. If your access token is expired you have to contact the api with your refresh token to get a fresh new access token.
As I said earlier some of my method needs you to be logged but if your access token is expired I want to try to refresh token before throwing an exception like with this method :
public async Task<bool> NeedRelog()
{
try
{
var validAuth = await ValidAuth();
}
catch
{
try
{
var refresh = await Refresh(Context.Client.Config.RefreshToken);
}
catch
{
return true;
}
}
return false;
}
ValidAuth check with the API if you are logged and if I have an exception then I'll try to refreshToken.
I want to tag method that need logged to call NeedRelog() and those who aren't tag to not call it.
I may just do it in every method but it wouldn't be clean.
What I've done so far
I've found a great tool : PostSharp that seems to fit my needs.
I've started to do a checkLog aspect like this :
[Serializable]
public class CheckLog : OnMethodBoundaryAspect, IOnStateMachineBoundaryAspect
{
public CheckLog()
{
ApplyToStateMachine = false;
}
public override void OnEntry(MethodExecutionArgs args)
{
var instance = (ApiService)args.Instance;
var res = instance.Parent.OAuth.NeedRelog().Result;
if (!res)
{
args.Exception = new Exception("Need to relog");
args.FlowBehavior = FlowBehavior.Return;
}
}
}
Where I'm stuck
The Main problem is with the call to my NeedRelog() Method. Due to the fact this is an async method I'm struggling to make my aspect await for it.
If my OnEntry method is async then It won't block the call if you are not logged.
If my OnEntry method is not async and I wait for needLog it freeze and nothing happen.
I really want to know to use this kind of "conditional method call" with postsharp, it looks awesome but the fact is after looking for hours in the documentation I didn't find a way to do what I want.
I'm starting to ask myself if it is even possible to achieve what I'm aiming to do.
Did you try using a way to make the call synchronous maybe with something like this stackoverflow.com/a/25097498/3131696 ? – M22an 5 hours ago
As I can't mark a comment as answering a question I quote your comment to make this question answered as it is said here : link
Thanks you for this M22an.
I am using Gecko Web browser version 21.0.1 and .net Framework 4.0 in my windows application.
When I navigate to certain web pages I get Pop up confirm message:
This web page is being redirected to a new location. Would you like to
resend the form data you have typed to the new location?
How can I disable this kind of messages?
So far I have tried the following settings, but they didn't help:
GeckoPreferences.User["security.warn_viewing_mixed"] = false;
GeckoPreferences.User["plugin.state.flash"] = 0;
GeckoPreferences.User["browser.cache.disk.enable"] = false;
GeckoPreferences.User["browser.cache.memory.enable"] = false;
You could try providing you own nsIPromptService2 / nsIPrompt implementation.
Run this early on program start up (Although after XPCom.Initalize)
PromptFactory.PromptServiceCreator = () => new FilteredPromptService();
Where FilteredPromptService is defined something like this:
internal class FilteredPromptService : nsIPromptService2, nsIPrompt
{
private static PromptService _promptService = new PromptService();
public void Alert(nsIDOMWindow aParent, string aDialogTitle, string aText)
{
if(/*want default behaviour */)
{
_promptService.Alert(aDialogTitle, aText);
}
// Else do nothing
}
// TODO: implement other methods in similar fashion. (returning appropriate return values)
}
You will also need to make sure that error pages are not enabled:
GeckoPreferences.User["browser.xul.error_pages.enabled"] = false;
I am new to SharePoint so I am following some Microsoft Learning Guides. One exercise is to create a feature reciever to modify the Web.Config file.
I detect the feature being activated or deactivated and call the following routine with the appropriate flag.
void setProliferationFlag(bool status)
{
SPWebApplication webApp = SPWebApplication.Lookup(new Uri("http://SharePoint"));
try
{
SPWebConfigModification mySetting = null;
if (status)
{
mySetting = new SPWebConfigModification();
mySetting.Path = "configuration/appSettings";
mySetting.Name = "add [#key='preventProliferation'] [#value='1']";
mySetting.Sequence = 0;
mySetting.Owner = "Lab05Owner";
mySetting.Type = SPWebConfigModification.SPWebConfigModificationType.EnsureChildNode;
mySetting.Value = "<add key='preventProliferation' value='1' />";
webApp.WebConfigModifications.Add(mySetting);
}
else
{
foreach (SPWebConfigModification modification in
webApp.WebConfigModifications)
{
if (modification.Owner == "Lab05Owner")
{
modification.Value = "<add key='preventProliferation' value='0' />";
}
}
}
webApp.Update();
webApp.Farm.Services.GetValue<SPWebService>().ApplyWebConfigModifications();
}
catch
{
}
The event receivers work fine. When I activate the feature this code is run, but when it reaches the "webApp.Update()" line it fails with an "Access Denied" error. No other detils on the error. I am not sure to what the access is denied.
I am running in my development environment on my laptop. This is a Sharepoint Server 2010 installation on Window 7.
Regards Tim
Most likely you will need administrative access. Look at the SPSecurity.RunWithElevatedPrivileges method which allows you to execute such actions within the system account's security context.
You will have to run the whole code elevated, that is including opening the SPWebApplication object. You method will then look like this:
void SetProliferationFlag(…)
{
SPSecurity.RunWithElevatedPrivileges(() =>
{
// … your code goes here …
});
}
Please also note, it's a very bad practice to have empty catch clauses in your code. Do always handle all exceptions, at least by logging them and rethrowing.