I am using primeface 3.2. i am using ajax poll to get every reaction into th gui.But ajax poll is not get stopped.i am trying to stop in server side.
i am using stop=true to stop the poll.
Update
Here is a link to the showcase Poll - Start/Stop
Old
If you want to stop the polling from the server side you could use the *RequestContext API *
Like described by cagataycivici
look at his (old) blog post
How to Stop Polling From Server Side
Code snippet
Client
<p:poll listener="#{bean.listener}" update="sth" stop="#{bean.stop}"/>
Server
private boolean stop = false;
public void listener() {
if(condition) {
stop = true;
}
}
Related
I am trying to write a Google Apps script which has a client and server side component. The client side component displays a progress bar. The client calls server side functions (which are called asynchronously), whose progress has to be shown in the client side progress-bar. Now, what I want is to be able to update the client side progress bar based on feedback from the server side functions. Is this possible?
The complexity is created due the the fact that JS makes the server-side calls asynchronously and hence I cannot really have a loop on the client side calling the functions and updating the progress bar.
I could of course split up the execution of the server side function in multiple steps, call one by one from the client side, each time updating the status bar. But I'm wondering if there's a better solution. Is there a way to call a client side function from the server side, and have that update the progress bar based on the argument passed? Or is there a way to access the client side progress-bar object from server side and modify it?
The way I've handled this is to have a middleman (giving a shout out now to Romain Vialard for the idea) handle the progress: Firebase
The HTML/client side can connect to your Firebase account (they're free!) and "watch" for changes.
The client side code can update the database as it progresses through the code - those changes are immediately fed back to the HTML page via Firebase. With that, you can update a progress bar.
Romain has a small example/description here
The code I use:
//Connect to firebase
var fb = new Firebase("https://YOUR_DATABASE.firebaseio.com/");
//Grab the 'child' holding the progress info
var ref = fb.child('Progress');
//When the value changes
ref.on("value", function(data) {
if (data.val()) {
var perc = data.val() * 100;
document.getElementById("load").innerHTML = "<div class='determinate' style='width:" + perc + "%\'></div>";
}
});
On the client side, I use the Firebase library to update the progress:
var fb = FirebaseApp.getDatabaseByUrl("https://YOUR_DATABASE..firebaseio.com/");
var data = { "Progress": .25};
fb.updateData("/",data);
Rather than tying the work requests and progress updating together, I recommend you separate those two concerns.
On the server side, functions that are performing work at the request of the client should update a status store; this could be a ScriptProperty, for example. The work functions don't need to respond to the client until they have completed their work. The server should also have a function that can be called by the client to simply report the current progress.
When the client first calls the server to request work, it should also call the progress reporter. (Presumably, the first call will get a result of 0%.) The onSuccess handler for the status call can update whatever visual you're using to express progress, then call the server's progress reporter again, with itself as the success handler. This should be done with a delay, of course.
When progress reaches 100%, or the work is completed, the client's progress checker can be shut down.
Building on Jens' approach, you can use the CacheService as your data proxy, instead of an external service. The way that I've approached this is to have my "server" application generate an interim cache key which it returns to the "client" application's success callback. The client application then polls this cache key at an interval to see if a result has been returned into the cache by the server application.
The server application returns an interim cache key and contains some helper functions to simplify checking this on the client-side:
function someAsynchronousOperation() {
var interimCacheKey = createInterimCacheKey();
doSomethingComplicated(function(result) {
setCacheKey(interimCacheKey, result);
});
return interimCacheKey;
}
function createInterimCacheKey() {
return Utilities.getUuid();
}
function getCacheKey(cacheKey, returnEmpty) {
var cache = CacheService.getUserCache();
var result = cache.get(cacheKey);
if(result !== null || returnEmpty) {
return result;
}
}
function setCacheKey(cacheKey, value) {
var cache = CacheService.getUserCache();
return cache.put(cacheKey, value);
}
Note that by default getCacheKey doesn't return. This is so that google.script.run's successHandler doesn't get invoked until the cache entry returns non-null.
In the client application (in which I'm using Angular), you call off to the asynchronous operation in the server, and wait for its result:
google.script.run.withSuccessHandler(function(interimCacheKey) {
var interimCacheCheck = $interval(function() {
google.script.run.withSuccessHandler(function(result) {
$interval.cancel(interimCacheCheck);
handleSomeAsynchronousOperation(result);
}).getCacheKey(interimCacheKey, false);
}, 1000, 600); // Check result once per second for 10 minutes
}).someAsynchronousOperation();
Using this approach you could also report progress, and only cancel your check after the progress reaches 100%. You'd want to eliminate the interval expiry in that case.
I've just created a project for working with REST API (using yii2 framework).
All issues of REST API is working really cool on localhost. But when bringing the project on server (also the same database is taken by), the authorization is not available. Now I'm using "yii\filters\auth\HttpBearerAuth"
Inside the model "implements IdentityInterface", there's finding-token function "findIdentityByAccessToken" that's so simple, the "validateAuthKey" function is returning always true; see below:
public static function findIdentityByAccessToken($token, $type = null){
return static::findOne(["token" => $token]);
}
public function validateAuthKey($token)
{
return true;
}
See any pictures:
https://www.flickr.com/photos/40158620#N03/20701523349/in/dateposted-public/
Anyone can have some experience on this problem, can you tell me how to solve it? Thanks for your kindness.
Note:
The project, I'm following https://github.com/NguyenDuyPhong/yii2_advanced_api_phong (It works fine on localhost; I also deployed exactly the project on my server, it raised the same problem )
To make sure that the server is configured right: I created 2 actions, 1 is authorized, another is not. I checked unauthorized action, it works very well. =======>
actionView is not authorized => getting API info. is ok
actionIndex is authorized by "yii\filters\auth\HttpBearerAuth" => FAIL
In my case the Problem was that the server removes Authorization Header
I needed to add this to .htaccess
SetEnvIf Authorization "(.*)" HTTP_AUTHORIZATION=$1
HttpBearerAuth used $user->loginByAccessToken to authorize see
validateAuthKey used by "loginByCookie"(and it seems that in this case not used)
Try to use QueryParamAuth for test purposes (it's easier to test)
i am trying to implement a Server Sent Events (SSE) webpage which is powered by Spring. My test code does the following:
Browser uses EventSource(url) to connect to server. Spring accepts the request with the following controller code:
#RequestMapping(value="myurl", method = RequestMethod.GET, produces = "text/event-stream")
#ResponseBody
public DeferredResult<String> subscribe() throws Exception {
final DeferredResult<String> deferredResult = new DeferredResult<>();
resultList.add(deferredResult);
deferredResult.onCompletion(() -> {
logTimer.info("deferedResult "+deferredResult+" completion");
resultList.remove(deferredResult);
});
return deferredResult;
}
So mainly it puts the DeferredResult in a List and register a completion callback so that i can remove this thing from the List in case of completion.
Now i have a timer method, that will periodically output current timestamp to all registered "browser" via their DeferredResults.
#Scheduled(fixedRate=10000)
public void processQueues() {
Date d = new Date();
log.info("outputting to "+ LoginController.resultList.size()+ " connections");
LoginController.resultList.forEach(deferredResult -> deferredResult.setResult("data: "+d.getTime()+"\n\n"));
}
The data is sent to the browser and the following client code works:
var source = new EventSource('/myurl');
source.addEventListener('message', function (e) {
console.log(e.data);
$("#content").append(e.data).append("<br>");
});
Now the problem:
The completion callback on the DeferredResult is called on every setResult() call in the timer thread. So for some reason the connection is closed after the setResult() call. SSE in the browser reconnects as per spec and then same thing again. So on client side i have a polling behavior, but i want an kept open request where i can push data on the same DeferredResult over and over again.
Do i miss something here? Is DeferredResult not capable of sending multiple results? i put in a 10 seconds delay in the timer thread to see if the request only terminates after setResult(). So in the browser the request is kept open until the timer pushes the data but then its closed.
Thanks for any hint on that. One more note: I added async-supported to all filters/servlets in tomcat.
Indeed DeferredResult can be set only once (notice that setResult returns a boolean). It completes processing with the full range of Spring MVC processing options, i.e. meaning that all you know about what happens during a Spring MVC request remains more or less the same, except for the asynchronously produced return value.
What you need for SSE is something more focused, i.e. write each value to the response using an HttpMessageConverter. I've created a ticket for that https://jira.spring.io/browse/SPR-12212.
Note that Spring's SockJS support does have an SSE transport which takes care of a few extras such as cross-domain requests with cookies (important for IE). It's also used on top of a WebSocket API and WebSocket-style messaging (even if WebSocket is not available on either the client or the server side) which fully abstracts the details of HTTP long polling.
As a workaround you can also write directly to the Servlet response using an HttpMessageConverter.
was trying to encapsulate a partial view to show feedback that i can push back to the client.
This Article shows a method of pushing back data using HTML5 Server-Sent events (SSE).
I noticed that if i opened up several browser tabs and then closed one i got exceptions as the logic didn't remove the respective stream from the ConcurrentQueue. I amended the code as below
private static void TimerCallback(object state)
{
StreamWriter data;
Random randNum = new Random();
// foreach (var data in _streammessage)
for (int x = 0; x < _streammessage.Count; x++)
{
_streammessage.TryDequeue(out data);
data.WriteLine("data:" + randNum.Next(30, 100) + "\n");
try
{
data.Flush();
_streammessage.Enqueue(data);
}
catch (Exception ex)
{
// dont re-add the stream as an error ocurred presumable the client has lost connection
}
}
//To set timer with random interval
_timer.Value.Change(TimeSpan.FromMilliseconds(randNum.Next(1, 3) * 500), TimeSpan.FromMilliseconds(-1));
}
I also had to amend the OnStreamAvailable member as the framework syntax had changed to the second parameter being a HttpContent rather than HttpContentHeaders
public static void OnStreamAvailable(Stream stream, HttpContent headers, TransportContext context)
The problem now is i am still getting inconsistant behaviour if i add or remove clients i.e it times out when trying to initialise a new client. Does anyone have any ideas or more examples of using SSE with WinAPI and the correct "framework of methods" to handle disconnected clients
Cheers
Tim
This article is actually an adaptation of my original article from May - http://www.strathweb.com/2012/05/native-html5-push-notifications-with-asp-net-web-api-and-knockout-js/ (notice even variable names and port numbers are the same :-).
It is a very valid point that you are raising, and detecting a broken connection is something that's not very easy with this setup. The main reason is that while ASP.NET (the host) allows you to check a broken connection, there is no notification mechanism between ASP.NET (host) and Web API informing about that.
That is why in order to detect a broken connection (disconnected client) you should really try writing to the stream, and catch any error - this would mean the client has been disconnected.
I asked the same question to Brad Wilson/Marcin Dobosz/Damien Edwards at aspconf, and Damien suggested using HttpContext.Current.Response.IsClientConnected - so basically bypassing Web API and obtaining the connectivity info from the underlying host directly (however there is still a race condition involved anyway). That is really .NET 4. He also pointed an interesting way in which this problem could be avoided in .NET 4.5 using an async cancellation token. Frankly, I have never got around to test it, but perhaps this is something you should explore.
You can see their response to this problem in this video - http://channel9.msdn.com/Events/aspConf/aspConf/Ask-The-Experts - fast forward to 48:00
I want to launch a local exe-file (without saving it to another location first) upon clicking on a link on a local html file.
It either needs to work in IE, Firefox, Chrome or Opera, I don't care. It's just for a presentation tomorrow.
It's simply not possible. If it was, it would be considered a security flaw and fixed. On Firefox within hours, on IE within some months.
UPDATE: You could try registering your custom protocol: http://openwinforms.com/run_exe_from_javascript.html
But I believe the browser will still prompt you whether you want to run the app.
I want to share my experience.
The accepted response says that it is not possible but it is quite possible indirectly.
If you want to execute an exe on a pc, it means that you have acces on this pc and you can install your exe on that machine.
In my case, I had to take a 3D scan from a 3D scanner via a web application. It seemed impossible at the beginning.
After lots of research, I found that we can send socket messages via javascript.
It means that if we had an application which listens a specific port, it can communicate with a website.
Let's explain how I did this.
In my web application, I created a javascript method like this :
function openCapron3DScanner(foot) {
$("#div-wait").show();
//Creates a web socket pointed to local and the port 21000
var ws = new WebSocket("ws://127.0.0.1:21000");
ws.onopen = function () {
//Sends the socket message to the application which listens the port 21000
ws.send(foot + "-" + #ProjectHelper.CurrentProject.Proj_ID);
};
ws.onerror = function myfunction() {
$("#div-wait").hide();
alert("Erreur connection scanner.");
}
ws.onmessage = function (evt) {
//Receives the message and do something...
var received_msg = evt.data;
if (received_msg == "ErrorScan") {
alert("Erreur scan.");
}
else {
refreshCurrentProject();
}
};
ws.onclose = function () {
$("#div-wait").hide();
};
};
And I created a windows forms application who listens the localhost and port 21000.
This application is hidden, only shown in icon tray.
The only thing to do is to add the application on windows startup via code on the first load to assure that the next restart of windows it will be executed and listen the port.
private static WebSocketServer wsServer;
static WebSocketSession LastSession;
private void Form1_Load(object sender, EventArgs e)
{
wsServer = new WebSocketServer();
int port = 21000;
wsServer.Setup(port);
wsServer.NewMessageReceived += WsServer_NewMessageReceived;
wsServer.Start();
}
private static void WsServer_NewMessageReceived(WebSocketSession session, string value)
{
if (value.StartsWith("ScanComplete-"))
{
//If the scan is ok, uploads the result to the server via a webservice and updates the database.
UploadImage(value);
//Sends a confirmation answer to the web page to make it refresh itself and show the result.
if (LastMacSession != null)
LastMacSession.Send("ScanComplete");
}
else if (value == "ErrorScan")
{
//If the C++ application sends an error message
if (LastMacSession != null)
LastMacSession.Send("ErrorScan");
}
else//call the 3D Scanner from the web page
{
LastSession = session;//Keeps in memory the last session to be able to answer via a socket message
//Calls the C++ exe with parameters to save the scan in the related folder.
//In could be don in this same application if I had a solution to consume the scanner in C#.
var proc = System.Diagnostics.Process.Start(#"C:\Program Files\MyProjectFolder\MyScannerAppC++.exe", projectID + " " + param);
}
}
I hope it will help.
Use System.Diagnostics.Process.Start() method.
protected void LinkButton1_Click(object sender, EventArgs e)
{
System.Diagnostics.Process.Start("notepad.exe");
}
You'll have to use C#, but since that's on your post, it should work. You'll also need the full path, if the file is not in your environment path that's loaded in memory.
For a 'regular link' you'd still need to place this in an ASPX page.....
Click me
We're getting really fugly now though.
You can't run an exe file on a website. (First, if it's a Linux server, exe files won't run on it and second, if you're on a Windows server, your host would kill the program immediately. And probably terminate your account.)
That link (assuming it was Play Now!) will just allow your user to download the file. (C:\Program Files\World of Warcraft\ exists on your computer, but it doesn't exist on the web server.)
You could setup a custom protocol on your local OS, if it's Windows, in regedit.
Check out this and this.
Then you create a simple HTML page, and place a link, something like this :
Start!
Given that you registered your custom "presentation" protocol, and configured it correctly in the registry, the application should launch when you click that link.