Caching - Call A Page (ashx Handler) From A Different Page?
Jul 12, 2010
I have a admin page in asp.net that adds data to a database. This database is available as a JSON string to external websites, however, since it's a lot of data, the external websites cache this data locally.I want to be able to ping the external websites to let them know the data has changed so they can referesh their cache. I figure I can setup an ASHX handler that receives a parameter telling them what data has changed, so they can both delete that data and refresh it.The only part I'm not sure about is the best way to call this external page from my admin page. Do I just do a regular WebRequest and discard the result? or is there a simpler way to call a page from code when you don't need the response?
Is it possible to call a handler using javascript code? e.g. i have a handler deployed at this location http://mysitename.com/getMyData.ashx. Can I call this handler or just request it using javascript?
We are using Google Analytics for our site, but since it uses client script in HTML output we are unable to track hits to any of our ASP.NET ASHX handler pages.
Page One is a home page, where I'm providing another version of that dropdown. I'd like the change event in this case to redirect control to Page Two, and then execute the event handler.
My cheap solution is just a Redirect with a querystring value that is handled on page load.
I have a dropdownlist in a user control and i want to perform different functions on the basis of the host page that hosts this user control when the selected index of the dropdownlist changes e.g. when the host page is locations i want the event to load locations for the selected item in the dropdown, when the hosting page is services i want to load services for the selected item in the dropdown. What is the best possible way to achieve this scenario.
I have a page with a number of user controls, In one of my user controls I have a button event. I turn on output cache for the user control that has the button and vary by control using the ID property of a hidden field control in the user control. whenever I turn on the output cache my button event doesn't fire.
When I click on the aspx Submit Button, the file selected in Silverlight control should be uploaded and after the completion of upload, the Server side event should get called.
I am a bit confused about these two sequence of events or processes happening in conjunction to each other. Does the page handler executes first or does the somepage.aspx get execute first or do they happen simultaneously?
I've got a simple ASHX handler that returns an dynamically generated image; the image is generated from a custom created class, and an object belonging to this class is passed to the handler using Session (I'd rather avoid using QueryString).The handler is used as the URL of an image on a ASP form which is very simple: a drop down list, a button and an image. Basically, depending on what the user selects from the list, the appropriate image will be generated once the button is pressed.
At the start the actual image has it's Visible property set to false; I don't want the handler to display anything before the data is all there.Once the button is pressed, the required Session parameter is added containing the necessary object, and the page is refreshed using Server.Transfer. When the Page_load method detects that the Session parameter has been correctly set, it sets the Visible parameter on the image to true.After that the handler fires up and generates the image.
So far so good... However, if the user now picks something different from the list and presses the button, despite the correct object being passed in the Session, the image won't be updated. In fact, the handler won't even fire up (if I put a breakpoint in there). I need to close the browser window and reopen it for it to work.Any ideas what could be the cause of such behaviour?I suspect the answer is very simple, and I just don't know something fundamental about ASP (or handlers)...
I'm implementing Outputcache in my application and it works fine, but the first time always take a lot to load and the next following request will be faster...
I would like to know if there is a way to initiate the page caching on the server side and serve the cached page upon the very first request, rather than have it triggered by the user one first time.
I'd like to pass data from one asp.net page to another. I've seen that using System.Web.Caching.Cache is a good way to accomplish this. I'm wondering if it's a good way to do it and also is there any cleanup or other things I need to keep in mind when you the Cache?
I am running a website using IIS6 and i wrote a simple generic handler which return smaller images when it receive image url as query string. My problem is that the server is applying gzip to some file types such as .aspx and .ashx. And that made my response image from the handler appear with lower quality because they are compressed.
How can i disable gzip for just this handler file, i hope for a solution without editing the IIS.
I've created code to retrieve an image from the file system using an ASHX handler. The code displays the image correctly in Chrome, but I get a broken image in IE:
On the top of that I have a button. On click of this button I am calling my webhandler using jquery/json, passing in some data to this handler. Now this data can containg html tags. So whenever I try to click that button it gives that Potential threat script
error. So I thought let me include ValidateRequest = false to my webpage.
Now when i do this it never hits my handler. I tried to debug also but my breakpoint is never hit in my handler. How to handle this.
This is how I call my handler:
[Code]....
where hidden value is the value which I want to pass to my handler and may contain html tags..
I create custom HTTP handler for auto generating file and I want to tell IIS7 to serve current request like normal static file because I need to use IIS and web.config file to control compression setting and any other HTTP header of current requested file.I know. there is an internal class called StaticFileHandler in ASP.net. But I cannot access it. Or you have any other way to work like this.
I would like to open some page from external web-application in iframe. Usualy, I would indicate URL for iframe like this: URL = [URL] BUT. I need to send not only 'ID=12' parameter. I need to send a lot of data to handler in order to be processed. Usualy I do it by following code:
Dim wrq As WebRequest = WebRequest.Create(Data_WS_URL) wrq.Method = "POST" Dim postData As String = "PubmedIDs=" & vInput wrq.ContentType = "Application/x-www-form-urlencoded" Dim byteArray As Byte() = Encoding.UTF8.GetBytes(postData)
But when you use this code - you recieve response from webrequest as some amount of data - text or binary. I may write this respone to the place on the page where I wanted to have iframe. But response cannot always be accaptable. (for example - I render asp:Treeview by ASHX handler - when I do to ashx page - it renders well, collapse-expand works fine; but if I write web-response of ashx page as text/html - then there's something wrong with javascript, tags ids and collapsing nodes). And webresponse cannot be represented as as URL. How to combine this two approaches
1) Clear URL which can be set as source for iframe 2) Extra data for web-request, larger then QueryString can handle
I have a gridview and in it is code to display an image
[Code]....
This works fine for pass one variable. but I need to send two variables 'ImageNum' and 'refID' to the Handler.ashx page, any ideas how, tried a few things in last few hours and as yet no joy!
Is it possible to add a messagebox to an ASHX Handler? I used a handler to pass data from a Web Service to an internal system and need a messagebox to pop up to ask the user to choose from one option or another.
For our application we provide users with file downloads that utilize handlers to serve the files. Currently, the way it is served to the user is through window.location. When using this, at times, it causes issues under IE8. When an error occurs, it cannot be caught under the page that called it.
A) Is there a way to serve an ashx file handler to the user where the page that called it can catch any exceptions made from thje handler B) What is the correct way to serve the handler, eg. window.open, window.location, etc. Would return false at the end of the javascript solve this? Are there any other ways
Is it possible to determine the HTTP protocol version (e.g. 1.0 vs. 1.1) used for a request within a .ashx handler? I can see all of the header information except for the version in Request.Params.
If not, what avenues are available to discover the HTTP protocol version when processing an HTTP request in ASP.Net?
implemented a generic handler in my application which works great for images, but when I manually type the handler URL in the browser with the image's querystring it prompts download instead of displaying. Here is my code:
public void ProcessRequest(HttpContext context) { if (this.FileName != null) {
I have created .ashx which implemented IRequiresSessionState, so I can create session variables in that ashx, it worked in IE, but doesn't work in Firefox.When access this session variable from other pages it's NULL.
We are providing downloads of our application setups through an ASHX handler in ASP.NET.
A customer told us he uses some third party download manager application and that our way of providing the files currently does not support the "resume" feature of his download manager application.
My questions are:
What are the basic behind resuming a download? Is there a certain HTTP GET request that tells me the offset to start at?
