I am creating a socket.io app using angular 2 on the frontend and I am getting a very weird behavior that I have never seen before when working with socket.io. I have no idea if my code is causing the issue or if it is something within the interaction between angular2 and socket.io, but if it is my code, I can't say what code I might need to post.
The mysterious behavior: At first instinct, my process for testing if my sockets connections are working properly is to open up an incognito tab, go to my project site, log in as a different user and see if API requests are emitted properly across the users. However; right now EVERY action that is made on either of the users happens to the other user. EX: if I type into a form one of the clients, the other clients form will get updated with the same information. If I click the forms submit button to post the data in the form, the other clients submit button will be clicked as well. Occasionally, it happens when navigating between states, where the other client will also navigate to the state. The behavior also occurs when logging on to a completely different computer, so imagine it is an issue with how socket.io emits data.
All the clients are connecting and disconnecting appropriately and are getting assigned unique socket ID's.
Turns out, the solution was a bit simpler than I was expecting it to be. I strange behavior occurs through a conflict with npm live-server running at the same time as my socket.io connection. I still cannot explain why the conflict was manifested as this sort of strange behavior, but at least I got it to stop by running the app as an express app serving up the index.html.
If anyone could explain why this might have been happening, I would love to hear.
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I have a NextJs app that uses SSR for all pages (so no static pages to worry about caching). Inside App.getInitialProps I get the user-agent to make an educated guess about whether the requests comes from a mobile device or desktop to render the correct layout on the server. But I came across an issue where sometimes the mobile layout got rendered on the desktop and vice-versa.
After extensive debugging, I came to this conclusion: if two user agents make a request to the same URL, there is a change next will confuse the request and serve the wrong answers. For example, if there is a chrome and a safari user simultaneously requesting the same URL, there is a chance the chrome user will get served the response meant for the safari user. In this example it's a non issue, but if Next messes up a mobile and a desktop request, the server and client get out of sync and the hydration phase fails.
Has anyone come across an issue like that? I guess I am either doing something wrong inside my _app.js or in the next.config.js, but I can't find anything regarding an issue like that
I have a an application that uses Angular for the frontend and communicates with an API running Django RF.
Now, let me try and outline what I'm trying to achieve in hopes of finding an easy solution.
When a user runs a report, a worker version of the API generates the report to prevent the main API from bogging down. The report runs for a couple seconds/minutes. The user refreshes the page and voila, their report is there.
What I'm trying to achieve is the elimination of the whole "user refreshes the page" portion of this process.
My goal is to do this via websockets.
I literally want something as simple as:
WEB: "Hey API, I want this report. I'll wait."
API: "Yo dog, you're reports done."
WEB: "Cool, let me refresh my report list. Thanks bud."
Now, we start to venture into an area I'm unfamiliar with. Websockets can do this, right? I just need to create a connection and wait for the all-clear to be sent by the worker.
Now, here's where it gets hairy.
I've spent the better part of the day going through libraries and just can't find what I need. The closest I've come is this, but it clashes with restframework. I get hit with tons of 404 errors and I think it has to do with the way rf manages urls.
I literally need a simple event listener. There's got to be a better way, right? To clarify, I don't want to do something brute-force like silently ping the API for report status. That gets a tad hinky. I want the API to tell me when it's ready.
In a basic way, can use something like django-websocket-redis and use Django signals to pass the messages around. ws4redis handles alot of the tricky bit. However, websockets are weird and honestly I doubt you need them. You could just poll some route that has the job state. If you need to get it done fast, I would go that route.
I'm having an issue where a long synchronous request will freeze Internet Explorer.
Let me explain the context : this is a web application which only supports IE8 and which can only use Synchronous*.
We have a Silverlight component with a save button. When the user presses the button, some information is sent to the server using a synchronous XMLHttpRequest, then some other actions are done client-side in the Silverlight component.
The server-side part includes calculations that will sometime take a while (several minutes).
In short, here is the code (c# silverlight part)
ScriptObject _XMLHttpRequest;
_XMLHttpRequest.Invoke("open", "POST", url, false);
_XMLHttpRequest.Invoke("send", data);
checkResponse(XMLHttpRequest);
doOtherThings();
I know that the server does its work properly because I can see in the verbose logs, the end of the page rendering for the "url" called from Silverlight.
However, in debug mode I can see that I never reach the "checkresponse" line. After calling the "send" line, IE will freeze forever, not unfreezing once the server log shows that "url" has been processed.
Also, I tried to add "_XMLHttpRequest.SetParameter("timeout", 5000)" between the "open" and the "send" lines. IE freezes for 5 seconds, then "checkresponse" and "dootherthings" are executed. Then IE freezes again while server-side calculations are processed and doesn't unfreeze once the server is done with its work.
IE timeout is supposed to be 3 hours (registry key ReceiveTimeout set to 10800000), and I also got rid of IE 2-connexions limit (MaxConnectionsPer1_0Server and MaxConnectionsPerServer set to 20).
Last important information : there is no issue when the server-side part only takes a few seconds instead of several minutes.
Do you know where the freeze could come from (IE bug, XMLHttpRequest bug, something I have done wrong) and how I can avoid this ?
Thank you !
Kévin B
*(while trying to solve my issue with the help of Google I found an incredible amount of "use asynch" and "synch is bad" posts; but I can't do this change in my app. Switching the application, ajax loads, and all server side calculations to asynchronous is a huge work which has been quoted for our client and is a long-term objective. I need a short-term fix for now)
Silverlight virtually requires that everything be done asynchronously. Any long running synchronous process will hang the browser if run on the UI thread. If you never reach the 'checkResponse' line of code it is possible that an unhandled exception was thrown on the previous line, and it is being swallowed. You can check in the dev tools of your browser to see if there are any javascript errors. I am surprised that calling XMLHttpRequest synchronously works at all since I would expect it to lock up the UI thread. But, the solution depends on your definition of async.
You can try:
calling the sync XHR request on a background thread and then marshalling to the UI thread (eg with Dispatcher.BeginInvoke) when you are ready
setting up an XMLHttpRequest wrapper that makes the call in async mode and raises a callback in Silverlight on completion
using HttpClient or WebClient
While these options are async, they don't require your server code to be written any differently (it can stay synchronous). I have seen a web server process a call for over an hour before finally returning a response, at which time the Silverlight app raised a callback. You could even use tools like the TPL await/async, or co-routines available in many mvvm frameworks to make the code appear very procedural/synchronous while still performing its actions asynchronously.
I hope you already solved your issue, but maybe this will be helpful to whomever may come across this post.
I noticed that every createchannel() replaces the iFrame url.
Is there any chance that due to a re-call to createChannel() my iFrame is being replaced by new iFrame BUT the binding between the clientID and the iFrame url wasn't updated?
For example:
I called "channel.create_channel(unique_id)" - and I got back the JS with 123.talkgadget.google....as an iFrame.
Then,
I called again with the same client id "channel.create_channel(unique_id)" - and I got back the JS with 456.talkgadget.google....as an iFrame.
Is there any chance that if I call now "channel.send_message(unique_id,msg)"
the message will be sent to 123.talkgadget.google instead of 456.talkgadget.google resulting that I didn't get the message?
Thanks!
I'm not 100% certain about this answer. I haven't tested thoroughly, it's a little hard to test since the dev_appserver behavior is quite different from the real server behavior.
I believe I have seen this behavior before (missing messages).
If you close the old channel from the client side it seems to make everything work properly.
I have not tried handling the case where you lose your internet connection and you can't close from the client side though.
The simple thing of calling FB.init (right before </body>) and then FB.getLoginStatus(callback) doesn't fire the callback function.
After some debugging, I think the SDK is stuck in the "loading" (i.e. FB.Auth._loadState == 'loading') phase and never gets to "loaded", so all callbacks are queued until the SDK has loaded.
If I force-fire the "loaded" event during debugging - with FB.Event.fire('FB.loginStatus', 'loaded') in case you're intersted - then the callbacks are invoked correctly.
Extra details that might be relevant:
My app is a facebook iframe app (loaded via apps.facebook.com/myapp)
I'm using IE9. The same behavior happens in Chrome
The app is hosted in http://localhost
What's going on? Why is the SDK never gets to loaded?
Thanks
UPDATE: Just tried it on Chrome and it worked (not sure why it didn't work before). Still doesn't work in IE
I had this same problem in Firefox 3.5 on Windows, but only on the very first log in to the page (probably because it was a slower machine and there was some weird timing issues going on).
I fixed it by forcing FB to refresh the login status cookie every time it checks:
FB.getLoginStatus(callback, true); //second argument forces a refresh from Facebook's server.
Without "force=true", sometimes it wouldn't fire the callback.
I had the exact same problem, and I solved it disabling "Secure Browsing" in the Facebook Security settings. Keeping Secure Browsing on forces the pages as "https", but I had no "Secure Canvas URL" set up, and this gave me a lot of errors in the console as well.
Hope this may help someone :)
In my experience, getLoginStatus() never calls the callback in Firefox when third-party cookies are disabled.
The original poster mentioned his application is hosted on http://localhost. I've never had luck with that, and believe it will cause problems.
Just today, I've had problems where getLoginStatus is not calling the callback on any browser, unless the user is actually connected to the app! I'm hoping this is a bug on facebook's end that they will solve.
Yet another possibility for FB.getLoginStatus not firing its callback is when using a "test" user account that has not been authorized to view that application. Its pretty bad that facebook doesn't give you any error messages.
I have also seen failed callbacks on bad appIds and redirectUrls.
I also ran into this issue specifically in Chrome. I tried calling it on page load and after a user-initiated action with no success.
It turned out that it was not a cross-domain issue. The getLoginStatus() call was being blocked by the Un-Passwordise extension in Chrome. As soon as I disabled the extension, it worked perfectly, even on page load.
More info about this issue here: Chrome-only cross-domain scripting errs in Facebook iFrame App upon FB.Login(..)
I understand that this question is a little old now, but I ran across it searching for solutions.
Double-check what you have set in your Facebook app configuration under the section "Website with Facebook Login". The Site URL domain must match the domain your page with the FB.getLoginStatus (and other related auth Javascript) is served from.
After hours of struggling, I realized that I could not reuse an existing app configuration I had on a new server and had to create a new app to handle the website login for this new server.
The other answers are probably equally valid in your specific case, but since there may be others like me who have struggled for a while on this, hopefully this gives you one other place to check. Making a new app with the correct Site URL was the answer in my particular case.