You can't do this with the .net updatepanels, least I don't believe it to be easy. Though you can do it with 2 separate AJAX calls..
This example is using JQuery for the AJAX and the code-behind is in vb.net.
Essentially what you need to do is make your first call to begin the long process, then make a second call, repeatedly, using a second method to get the status of the long one.
AJAX
This is your main call to the long process. If needed, you will need to pass in the data to the method. Notice there is a processName. This should be a random string of sorts to ensure that you get the status of this process only. Other users will have a different random processName so you don't get confused status.
var processName = function GenerateProcessName() {
var str = "";
var alhpabet = "abcdefghijklmnopqrstuvwxyz";
for (i = 1; i < 20; i++) {
str += alhpabet.charAt(Math.floor(Math.random() * alhpabet.length + 1));
}
return str;
}
function StartMainProcess(){
$j.ajax({
type: "POST",
url: "/MyWebservice.asmx/MyMainWorker",
data: "{'processName' : '" + processName + "','someOtherData':'fooBar'}",
contentType: "application/json; charset=utf-8",
dataType: "json",
success: function (msg) {
if (msg.d) {
// do a final timerPoll - process checker will clear everything else
TimerPoll();
}
}
});
TimerPoll();
}
Your second AJAX call will be to another method to get the progress. This will be called every XXX time by a timer method.
This is the TimerPoll function; which will fire every 3 seconds in this case
function TimerPoll() {
timer = setTimeout("GetProgress()", 3000)
}
And finally, the GetProgress() function to, well, get the progress. We have to pass in the same processName used above, to get the process of this users call only
function GetProgress() {
// make the ajax call
$j.ajax({
type: "POST",
url: "/MyWebService.asmx/MyMainWorkerProgress",
data: "{'processName' : '" + processName + "'}",
contentType: "application/json; charset=utf-8",
dataType: "json",
success: function (msg) {
// Evaulate result..
var process = msg.d
if (process.processComplete) {
// destroy the timer to stop polling for progress
clearTimeout(timer);
// Do your final message to the user here.
} else {
// show the messages you have to the user.
// these will be in msg.d.messages
// poll timer for another trip
TimerPoll();
}
});
}
Now, in the back-end, you will have a couple of web methods that your AJAX communicates with. You will also need a shared/static object to hold all of the progress information, along with anything you want to pass back to the user.
In my case, i created a class which has its properties filled and passed back with every call to MyMainWorkerProcess. This looks a little like this.
Public Class ProcessData
Public Property processComplete As Boolean
Public Property messages As List(Of String) = New List(Of String)
End Class
I also have a shared property using this class, which looks like... ( this shared property is capable of holding multiple process progresses by multiple users - hence the dictionary. the key of the dictionary will be the process name. All progress data will be in the class ProcessData
Private Shared processProgress As Dictionary(Of String, ProcessData) = New Dictionary(Of String, ProcessData)
My main worker function looks a little like this. Notice that we first make sure there isn't another processProgress with the same
<WebMethod()> _
<ScriptMethod(ResponseFormat:=ResponseFormat.Json)> _
Public Function MyMainWorker(ByVal processName as string, ByVal SomeOtherData as string) as Boolean
'' Create progress object - GUI outputs process to user
'' If the same process name already exists - destroy it
If (FileMaker.processProgress.ContainsKey(processName)) Then
FileMaker.processProgress.Remove(processName)
End If
'' now create a new process
dim processD as ProcessData = new ProcessData() with {.processComplete = false}
'' Start doing your long process.
'' While it's running and after whatever steps you choose you can add messages into the processData which will be output to the user when they call for the updates
processD.messages.Add("I just started the process")
processD.messages.Add("I just did step 1 of 20")
processD.messages.Add("I just did step 2 of 20 etc etc")
'' Once done, return true so that the AJAX call to this method knows we're done..
return true
End Function
now all that is left is to call the progress method..All this is going to do is return the dictionary processData that has the same processName we set up earlier..
<WebMethod()> _
<ScriptMethod(ResponseFormat:=ResponseFormat.Json)> _
Public Function MyMainWorkerProgress(ByVal processName As String) As ProcessData
Dim serializer As New JavaScriptSerializer()
If (FileMaker.processProgress.ContainsKey(processName)) Then
Return processProgress.Item(processName)
Else
Return New ProcessData()
End If
End Function
And voila..
So to recap..
- Create 2 web methods - one to do the long process and one to return it's progress
- Create 2 separate calls to these web methods. The first is to the main worker, the second, which is repeated xx seconds, to one that will give the progress
- Output your messages to the user however you see fit...
Disclaimer...
I haven't provided an answer this long on here before.. It might not follow the format people are used to seeing. Sorry if it all seems a little confusing :) I have copied most of the code from a running project so it should work.. though don't shoot me if there are a few typos :)
