In webdriver, While opening a page
Webdriver.get("www.yahoo.com");
If an element I want to click appears instantly, unnecessarily I have to wait till the page load completes.
Is there any solution/suggestion to overcome this problem?
Thanks in Advance
In WebDriver there are three implicit waits
implicitlyWait
driver.manage().timeouts().implicitlyWait(30, TimeUnit.SECONDS);
pageLoadTimeout
driver.manage().timeouts().pageLoadTimeout(30, SECONDS);
setScriptTimeout
driver.manage().timeouts().setScriptTimeout(30,SECONDS);
You can specify the time in above methods to wait before throwing exception.
See this link for more information
In Default the Web driver instance will wait until the page load completes. But you can change the timeout duration using
//Assume driver instance is initialized properly
driver.manage().timeouts().pageLoadTimeout(5, TimeUnit.SECONDS);
If the page load exceeds the given duration mean it will throw the TimeOut Exception
For more info.
Try FluentWait, though this is for handling ajax element but may be useful for your case. here is the resource -
http://www.thoughtworks-studios.com/twist/2.3/help/how_do_i_handle_ajax_in_selenium2.html
Related
I have a function that parses an input file.
Private Function getSvSpelOdds(ByVal BombNo As Integer) As Boolean
Dim InputFileBase As String = HttpContext.Current.Application("InputFileBase")
strInputFile = InputFileBase & "PC_P7_D.TXT"
OddsReader = New StreamReader(strInputFile)
'some other code
End Function
If the file is not there (getSvSpelOdds returns False), I would like to retry after 30 seconds.
To achieve this I use a timer.
If Not getSvSpelOdds(y) Then
Timer1.Interval = 30000
End If
Private Sub Timer1_Elapsed(sender As Object, e As System.Timers.ElapsedEventArgs) Handles Timer1.Elapsed
getSvSpelOdds(y)
End Sub
Problem is that when timer fires the HttpContext.Current (used to get the value of gloal variable) is null.
Should I use some other approach to get this to work?
As already described HttpContext should be null as Timer_Elapsed is called in different thread. But you may use System.Web.HttpRuntime.Cache to pass filename, cache should be accessible from all threads.
HttpContext.Current only gives you the context you want when you call it on the thread that handles the incoming thread.
When calling it outside of such threads, you get null. That matches your case, as Timer1_Elapsed is executed on a new thread.
Should I use some other approach to get this to work?
Almost certainly, yes. 30 seconds is a long time to wait without giving any feedback to users.
It would probably be better to return a "no results are available yet, but we're still looking" page to the user. That page can be set to refresh automatically after 30 seconds, by adding a suitable meta-tag:
<META HTTP-EQUIV="refresh" CONTENT="30">
And you then get a fresh request/response cycle on the server. And haven't tied up server resources in the meantime.
Other answers seems to address the other part of your question (about why it doesn't work in the timer callback)
The Elapsed event on the Timer will run on a separate thread therefore its expected behaviour for the current context to be null.
You can only access it from the same thread.
Should I use some other approach to get this to work?
Yes, it's not generally a good idea to mix ASP.NET and threads given the complexity of how ASP.NET works. Like already mentioned its not a great UX to have no feedback for 30 seconds, its better to let the user know what's actually going on.
Also, you need to determine whether the timeout length is appropriate or whether a timeout is needed at all. I don't know the nature of your application but I assume there is some external means for the file to be generated and picked up by your site.
I'm running a method in an overridden Page OnUnload, but only if the Page_PreRender method has run.
Obviously, I can flip a class-level bool when I'm in Page_PreRender and check it in OnUnload, but if there's a more intrinsic way to tell is Page_PreRender has run, I'd like to use that.
Any ideas?
Thanks for any thoughts.
UPDATE: Let me rephrase my question slightly. I'm looking for the answer to whether there is a simple way, inherent in the Page life cycle, perhaps a property that is set by the ASP.Net frameowork, perhaps something else, that is different after Page_PreRender has run versus when Page_PreRender has not run.
I am currently setting a boolean in Page_PreRender to tell me if it has run. It works, but I don't like this solution if there is a way to accomplish the same thing without adding the extra boolean check. Creating an event that fires during Page_PreRender is the same level of redundancy I'd like to avoid, if possible.
You mention (in your comments on another post) that your problem manifests itself when calling Response.Redirect() because it throws a ThreadAbortException, which leads to your OnPreRender() event not being called. So why not use this instead?:
Response.Redirect("~/SomePage.aspx", false);
The "false" you see there indicates if execution of the page should terminate right there and then. By default, Response.Redirect() uses "true". If you need your OnPreRender() event to run so that your OnLoad() event will have everything it needs, then set it to "false" and just make sure you either jump to the end of your Page_Load() after calling Response.Redirect() or that the code that would execute after it is fine to run.
Maybe you don't like the idea of passing "false" using the overloaded Response.Redirect() method so that's why you didn't go that route. Here is some documentation that may help sway your mind:
Microsoft states that "passing false for the endResponse parameter is recommended" because specifying "true" calls the HttpResponse.End() method for the original request, which then throws a ThreadAbortException when it completes. Microsoft goes on to say that "this exception has a detrimental effect on Web application performance". See here in the "Remarks" section: http://msdn.microsoft.com/en-us/library/a8wa7sdt.aspx
This was posted last year on MSDN:
The End method is also on my “never
use” list. The best way to stop the
request is to call
HttpApplication.CompleteRequest. The
End method is only there because we
tried to be compatible with classic
ASP when 1.0 was released. Classic
ASP has a Response.End method that
terminates processing of the ASP
script. To mimic this behavior,
ASP.NET’s End method tries to raise a
ThreadAbortException. If this is
successful, the calling thread will be
aborted (very expensive, not good for
performance) and the pipeline will
jump ahead to the EndRequest event.
The ThreadAbortException, if
successful, of course means that the
thread unwinds before it can call any
more code, so calling End means you
won’t be calling any code after that.
If the End method is not able to raise
a ThreadAbortException, it will
instead flush the response bytes to
the client, but it does this
synchronously which is really bad for
performance, and when the user code
after End is done executing, the
pipeline jumps ahead to the EndRequest
notification. Writing bytes to the
client is a very expensive operation,
especially if the client is halfway
around the world and using a 56k
modem, so it is best to send the bytes
asynchronously, which is what we do
when the request ends the normal way.
Flushing synchronously is really bad.
So to summarize, you shouldn’t use
End, but using CompleteRequest is
perfectly fine. The documentation for
End should state that CompleteRequest
is a better way to skip ahead to the
EndRequest notification and complete
the request.
I added this line after calling Response.Redirect(), as MSDN suggests, and noticed everything appeared to run the same. Not sure if it's needed with 4.0, but I don't think it hurts:
HttpContext.Current.ApplicationInstance.CompleteRequest();
Update 1
Using "false" in the call to Response.Redirect() avoids the ThreadAbortException, but what about other Unhandled Exceptions that could be thrown on your page? Those exceptions will still cause your problem of OnUnload() being called without OnPreRender(). You can use a flag in OnPreRender() as everyone suggests to avoid this, but if you're throwing Unhandled Exceptions, you've got bigger problems and should be redirecting to an error page anyway. Since Unhandled Exceptions aren't something you plan to throw on every postback, it would be better if you wrapped your OnUnload() logic in a Try-Catch. If you're logging and monitoring your exceptions you will see that an Unhandled Exception was thrown right before logging a NullReference Exception in the OnUnload() event and will know which one to ignore. Because your OnUnload() will have a Try-Catch, it will safely continue processing the rest of the page so you can Redirect to the error page as expected.
Update 2
You should still have your OnUnload() wrapped in a Try-Catch, but I think this is what you're really looking for (remember IsRequestBeingRedirected will be true when calling Response.Redirect or when redirecting to an error page after an Unhandled Exception).:
if (HttpContext.Current.Response.IsRequestBeingRedirected != true)
{
//You're custom OnUnload() logic here.
}
With this, you will know if it is safe (or even worth it) to process your custom logic in the OnUnload() event. I realize I should have probably lead off with this, but I think we learned a lot today. ;)
NOTE: The use of Server.Transfer() will also call the dreaded Response.End(). To avoid this, use Server.Execute() with the preserveForm attribute set to "false" instead:
Server.Execute("~/SomePage.aspx", false);
return;
NOTE: The thing about Server.Execute("~/SomePage.aspx", false); is that IsRequestBeingRedirected will be false, but your OnPreRender() will still execute, so no worries there.
The answer is Yes, you can, but not always :)
According the Reflection code, the ScriptManager class contains the private bool field _preRenderCompleted, which is set to true while handling internal IPage interface PagePreRenderComplete event.
You can use the Reflection to get this field from ScriptManager.GetCurrent(page) resulting object
I am not sure what exactly you mean by this. According to the ASP.NET Page Lifecycle PreRender always runs before Unload. If you perform some if condition inside this PreRender event and you would like to test in the Unload whether the condition was satisfied a boolean field on the page class seems a good idea.
Add trace=true to the page directive.
Set a boolean field in the PreRender event handler, then check if it was set in the Unload event handler.
Create a custom event that fires in the PreRender event.
I don't think there is any sort of state stored because the ASP.NET engine does not really need that, as it knows its state implicitely.
Searching with .NET Reflector, it seems the page render events are raised from this internal System.Web.UI.Page method:
private void ProcessRequestMain(bool includeStagesBeforeAsyncPoint, bool includeStagesAfterAsyncPoint)
You can have a look at it, there is no notion of state. The only information you can get is the trace. If you have access to the Unload event, then you should have access to the trace? or I miss something :-)
Since the trace is in fact a dataset undercovers (see my answer here: Logging the data in Trace.axd to a text/xml file), you maybe could get the information. But
setting trace=true is not recommended in production though...
how to display something one time every hour in asp.net ?
example for show messeage in Begining hour one time only?
i use for asp.net ajax timer control?
protected void Timer1_Tick(object sender, EventArgs e)
{
MessageBoxShow(Session["playsound"].ToString());
Session["playsound"] = 1;
}
but alway null?
---------------------------
Message from webpage
---------------------------
Object reference not set to an instance of an object.
---------------------------
OK
---------------------------
Sounds like your session might have timed out. If, between AJAX calls, your session expires on the server, then the ToString invocation may be operating on a null reference:
MessageBoxShow(Session["playsound"].ToString());
This would appear to coincide with what the AJAX client script is attempting to tell you.
This could also be the result of Session["playsound"]; being uninitialised.
The default session expiry duration for ASP.NET is 20 minutes, which you should be mindful of if you're executing an hour long timer.
You can use the
window.setInterval
method
It calls a function repeatedly, with a fixed time delay between each call to that function.
intervalID = window.setInterval(func, delay[, param1, param2, ...]);
Read more info
window.setInterval
On the client?
The only way I know to do this is via a javascript timer.
One way of doing this could be to have an session variable with NextTime to show the item on the page. If its null one could display the item now (or get the NextTime scheduled). On every page refresh, if the current time is after the Next Time, show the item and reset the NextTime session variable to the next Hour.
This would only work if the user is navigating the site and the page is being refreshed.
You can use the javascript variable window.name which keeps its value between page refreshes.
You could store a 'last checked time' in there and compare it with the current time.
If the user navigates to another site and that site clears this variable then your back to square one.
An easy answer would be to use a small cookie to store the original time and then query it every so often (~5 min?) this way the session won't run out and you're not SOL if the user leaves the page (if that's what you want).
DISCLAIMER: I haven't really dipped my toes into AJAX yet even though I've been programming ASP.net all summer, so excuse me if this isn't possible.
Does anyone knows whats the default timeout value for the responder object? is there a time limit when the flex app will wait for result and call fault handler instead of result handler?
Use the getter / setter to access the requestTimeOut property of your RemoteObject.
More info here: RemoteObject
First off... I would recommend setting a cfquery timeout in any cfc call (if you're using coldfusion). If the query times out then it will hit your fault.
Check out "requestTimeout" here
http://livedocs.adobe.com/flex/2/langref/mx/rpc/remoting/RemoteObject.html#propertySummary
You can also just create your own timer with a timer object
Once the timer reaches a certain point you can "disconnect" or "logout", and call the fault function manually
Let me know if this helps.
I am seeing strange behaviour with the flash.media.Sound class in Flex 3.
var sound:Sound = new Sound();
try{
sound.load(new URLRequest("directory/file.mp3"))
} catch(e:IOError){
...
}
However this isn't helping. I'm getting a stream error, and it actually sees to be in the Sound constructor.
Error #2044: Unhandled IOErrorEvent:.
text=Error #2032: Stream Error. at... ]
I saw one example in the Flex docs where they add an event listener for IOErrorEvent, SURELY I don't have to do this, and can simply use try-catch? Can I set a null event listener?
IOError = target file cannot be found (or for some other reason cannot be read). Check your file's path.
Edit: I just realized this may not be your problem, you're just trying to catch the IO error? If so, you can do this:
var sound:Sound = new Sound();
sound.addEventListener(IOErrorEvent.IO_ERROR, ioErrorHandler);
sound.load(new URLRequest("directory/file.mp3"));
function ioErrorHandler(event:IOErrorEvent):void {
trace("IO error occurred");
}
You will need to add a listener since the URLRequest is not instantaneous. It will be very fast if you're loading from disk, but you will still need the Event-listener.
There's a good example of how to set this up (Complete with IOErrorEvent handling) in the livedocs.
try...catch only applies for errors that are thrown when that function is called. Any kind of method that involves loading stuff from the network, disk, etc will be asynchronous, that is it doesn't execute right when you call it, but instead it happens sometime shortly after you call it. In that case you DO need the addEventListener in order to catch any errors or events or to know when it's finished loading.