When the user checks a checkbox and clicks a specific button, I already do some stuff on the server and then use Response.Redirect to "reset" the page. I also have a function which allows me to "export" a datatable to an excel spreadsheet by using a application/vnd.openxmlformats-officedocument.spreadsheetml.sheet response.
Both of these work fantastically when separate. But, what I now need to do is have both events take place after one button click.
It seems like I would need to Flush the response after exporting to excel and then redirect the response afterward, but I can't seem to be able to get this to work. I could be way off on this one, and need some assistance. Thanks
EDIT:
Alright, I have decided to go about this by opening a new page (downloadexcel.aspx) which will then initiate the download and close after the download is completed. I am opening downloadexcel.aspx using javascript by writing it to the response of the current page. For some reason, however, the window is not being opened before the original page is re-directed. Is their a method to be called before I redirect? Maybe I have a syntax issue?
Response.Write("<script type='text/javascript'>window.open('~/DownloadExcel.aspx', '', ''); </script>")
Response.Redirect("~/BulkImport.aspx")
If you want to do this in a single HTTP request then you will have a single response. You can either return HTTP 200 (with the file as the content) or HTTP 301 to redirect the client. You can't return both.
The bottom line is that you will need to rethink your approach, you could "clean" the form on the client side using javascript instead of reloading the page using a redirect.
Related
I have a form that dynamically generates a PDF based on database data. But I don't want to navigate away from the form whilst the PDF is generated and downloaded. So I am using response.redirect to call the .aspx page that generates the PDF and serves it via stream (Have done for many years) so there may be a better option out there now. However I have found people are logging out before the PDF has been sent to the browser which is causing issues.
Is there a way to detect when the reponse.redirect has finished and the file has been downloaded?
I have tried using postmessage and a listener but this doesn't work.
I've also tried setting up and EndRequestHandler as below in my main form:
Sys.WebForms.PageRequestManager.getInstance().add_endRequest(EndRequestHandler) ;
But this hasn't worked either. The browser is aware as as the tab with the main form has a progress icon in, so there must be a way to intercept the complete event.
Might not be accurate like you want it but I do something sort of similar. When the button is clicked, a "Please Wait..." message appear until the file is ready to be downloaded. The way I do it is the client wait for a cookie. When the server is ready to send the file (after processing) it sets a cookie. Even if the cookie was set in a different request, the client still gets the updated value.
I've put some objects in an S3 bucket and I want to log everytime a client makes a request to one of those objects.
I'm using Umbraco 4.8 as my back-end with some custom code running.
The solutions I've come up with:
Set the link to an ASP page that pulls the object from S3 and sends it back as the response. The problem I see there is then the client has to wait for ASP to load the file before it can begin downloading the file.
Set the link to an ASP page that logs the request and returns a Response.Redirect to the S3 object. To me this seems like an unnecessary redirect and the client might cache that redirect and not hit my server the next time they access that object.
Does anyone have any other solutions or thoughts on how to achieve this? Any help would be appreciated.
I would use jquery and google analytics. Add a class to each link that you want to track and then use jquery to manipulate the onclick event to something like:
link text
Replacing the three variables appropriately ('s3-Bucket-Request', 's3-actual-bucket-name', 'current-page'). If you then put the jquery at the head of each page you have a reusable function.
start:
link text
jquery:
$('.ga').attr("onclick", "__gaq.push(['_trackEvent', 's3-Bucket-Request', 's3-actual-bucket-name', 'current-page']);");
end:
link text
Depending on how accurate you need this to be, you could also do it client side. Using jQuery, etc, add a click handler to a href tags that makes an ajax request to a controller, logging the activity.
i've been asked this question and id not know the answer.
Thanks for any help!
Postback is a term used often in ASP.NET when a WebForm POSTs the single form back to the server and invokes some event in the code behind (like a click on a button for example). You could still use normal GET requests though to redirect to a given web page. For example you could use an anchor:
Go to page 2
When the user clicks on the anchor there is no postback occuring but a GET request to the target web page.
Another possibility is the user typing directly the address of the web page in his browser address bar.
Yet another possibility is to use javascript to perform an AJAX request which allows to invoke a web page without redirecting away from the current page. You could use any HTTP verb with AJAX.
We can use javascript code to do some function without postback. This will save the time for the request and response to the server. But this client side. you can't reach the server without posting back.But my mean you can do functionality by javascript which does not postback the page.
Hope it may help.
If you like to categories the call to the server you can say that there are two types.
The GET and the POST
The POST is the post back and are the parameters that you send using a form
and the GET that are the parameters that you can send from the url.
More about:
http://www.cs.tut.fi/~jkorpela/forms/methods.html
http://thinkvitamin.com/code/the-definitive-guide-to-get-vs-post/
http://catcode.com/formguide/getpost.html
but I think the interview question was about the Ajax call, and this is probably what they try to see if you know, how to use Ajax to reach the server with javascript and not make postback. But you need to know that Ajax can make POST back, but this is done with out leave the page, with out make a full page post back.
Is it possible to determine - server-side - whether a page has been loaded within an IFrame?
When certain errors happen in my application the user gets redirected to Default.aspx and an error message is shown. The text of that error message gets set in session by exception handling code. The error message gets cleared from session once it has been shown.
However, part of my application has to use an IFrame (it's doing a 3D Secure card payment check, which mandates an IFrame in order to display the card provider's authentication UI). If an error takes place during this process my redirect takes effect within the IFrame. I am using JavaScript to detect this and reload Default.aspx correctly, but this means that I get two Page_Loads in rapid succession, and the error message only gets shown on the first one (and then cleared).
You can do it in client side: How to identify if a webpage is being loaded inside an iframe or directly into the browser window?
The workaround i found is put some identifier into querystring of a url opened inside iframe.
I don't think you can detect in the sense of having some sort of Page.IsInIFrame() kind of functionality, but you could consider having different base classes for those pages that are loaded in an IFrame and those that aren't so that you can know the error is from a request that was for an IFrame page that may help to some extent.
There's no way from the server-side. The only way is via javascript. When you do the redirect, can you pass the error message or code via a querystring?
Won't it work to redirect using Javascript with window.location? Forcing a full page redirect?
This is impossible because client can open iframe with javascript disabled. http://caniuse.com/#feat=iframe-sandbox
simply, check the url of current page..
if it's the same with the IFrame page then redirect to Default.aspx or whatever.
Dim urlpath1 As String = HttpContext.Current.Request.Url.AbsoluteUri
If Right(urlpath1, 13) = "WebForm1.aspx" Then
Response.Redirect("~/")
Else
Response.Write("It's OK!")
End If
I have an asp.net application that runs exclusively on IE7 (internal web site).
When a user needs to enter data, I pop up a child window with a form. When the form closes, it calls javascript:window.opener.location.reload(true) so that the new data will display on the main page.
The problem is that the browser complains that it must repost the page. Is there any way to turn this feature off?
No, but there is a solution. Its generally considered good design to use a 302 redirect immediately after someone posts data to a page. This prevents that popup from ever occuring. Allow me to elaborate.
1) The user fills in a form and submits data via POST.
2) The backend receives the data and acts upon it.
3) Instead of returning the content to the user, the backend issues a 302 redirect as soon as its done processing the page (possibly redirecting the user back to the exact same url, if need be)
4) The page that the user will see is the page you told their browser to redirect to. They will load up the redirected page with a standard GET request. If they try to refresh the page, it will not repost the data. Problem solved.
This is a problem with the usual "postback" way of ASP.NET. If you need to reload a page without this warning, this page must come from a GET, not a POST. You could do a Response.Redirect("...") yourself. But this will destroy the use of viewstate.
asp.net mvc fixes this issue, not an ie7 only problem but a security feature of most browsers. No fix that I know of except you could just update the content in the main form with js rather than reloading the whole page
It's because the page in window.opener comes from a POST Request
Maybe you can use
javascript:window.opener.location = window.opener.location; to do just a GET request if the data can be fetched without a POST.
I do not believe that there is a way to do that. Instead, why not direct the parent window to a page without a reload.
javascript:window.opener.location='your url'
AFAIK, not via your scripts.
You might try:
window.opener.location = '#';
It should circumvent the browser reposting. And, you can adjust the hash name as needed.
If you move from page1 to page2, and want to disable the browser from going back to page 1,then add the following at the top of page1.
<script>
if(window.history.forward(1) != null)
window.history.forward(1);
</script>