Best way to set up a custom WebHook Receiver in ASP.NET? - c#

We're looking to set up a WebHook receiver in our asp.net application. We've already got a simple aspx document that is able to receive and process the WebHook on the server side when it's received.
While this works, we're pretty sure an aspx file that just grabs and processes whatever is sent to it isn't the best option security-wise. Also, it doesn't need to serve a aspx document back so we figure that's probably a waste of resources.
In the process of looking for alternatives, we've found the following:
The Microsoft.AspNet.WebHooks.Receivers NuGet Package - After some research we discovered that the documentation for this isn't great and every once in a while you'll see mentions of Azure which we don't use. Makes it even more confusing.
Using a handler to do the processing instead of an aspx page - We thought maybe a handler would be able to run just on the server side when a POST is received so we don't need to send a whole aspx page back. This doesn't appear to be a common use for these though.
Any search tips or things we may be missing?

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Which Event to use in aspx page to read POSTed data?

I have seen 100 examples of posting from a HTML form to a .aspx page and using Request.Form to see the values; this makes sense.
I'm trying to build up a small example to mimic a project where data is posted to a blank .aspx page and the values just read server side. I know it seems odd to leverage a .aspx page for this purpose, but that's the objective.
I want to know which event will be raised on the server in my Default.aspx page when data is POSTed to it? I doub't Page_Load() fires because the page is not being pyhsically opened, rather just hosted in IIS on the server.
Which event will I use in Default.aspx to read or siphon out the POSTed data?
EDIT: 'mimic' is the keyword here. This is not a new project, but I don't have the source for the original - it's a prototype to mimic an implemented example. If I was starting from scratch exposing something to POST data I'd most likely choose WebAPI nowadays.
Page_Load()
If the page has no content and its sole purpose is to receive these values, then Page_Load() would be the sensible place to capture the values and pass them along to wherever they need to go in the business logic.
I doub't Page_Load() fires because the page is not being physically opened
Sure it is, at least as far as the page itself is concerned. How the client requests the page and what the client does with the response from the page is immaterial in this regard. If the page is requested, it's "loaded" server-side and returned as the response.
I know it seems odd to leverage a .aspx page for this purpose, but that's the objective.
Very odd indeed. Though not uncommon. An ASHX handler may suit your needs more effectively, as might a WCF service endpoint. But without more information about what you're building and how it's going to be maintained, this is all hearsay.

IE shows a previously cached version of my page

my scenario is this; the user selects the list of reports they wish to print, once they select and click on the a button, i open up another page with the selected reports ready for printing. I am using a session variable to pass reports from one page to another.
first time you try it, it works fine, second time you try it, it opens the report window with the previous selected reports. I have to refresh the page to make sure it loads the latest selections.
is there a way to get the latest value from the session every time you use it? or is there a better way to solve this problem. open for suggestions...
Thanks
C# Asp.net, IE&7 /IE 8
After doing some more checking maybe if you check out COMET it might help.
The idea is that you can have code in your second page which will keep checking the server for updated values every few seconds and if it finds updated values it will refresh itself.
There are 2 very good links explaining the imlementation.
Scalable COMET Combined with ASP.NET
Scalable COMET Combined with ASP.NET - Part 2
The first link explains what COMET is and how it ties in with ASP.NET, the second link has an example using a chat room. However, I'm sure the code querying for updates will be pretty generic and can be applied to your scenario.
I have never implemented COMET yet so I'm not sure how complex it is or if it is easy to implement into your solution.
Maybe someone developing the SO application is able to resolve this issue for you. SO uses some real-time feature for the notifications on a page, i.e: You are in the middle of writing an answer and a message pops up in your client letting you know someone else has added an answer and to click "here" to refresh.
The proper fix is to set the caching directives on the HTTP response correctly, so that the cached response is not reused without validation from the server.
When you fail to specify the cache lifetime, the client has to "guess" how long the response is good for, and the browser's guess probably isn't what you want. See http://blogs.msdn.com/b/ie/archive/2010/07/14/caching-improvements-in-internet-explorer-9.aspx
It's better to use URL paramaters. So you have a view of value of the paramaters.

C# asp.net asynchronous function call after file is uploaded

I'm facing the following issue:
I have a C# asp.net file upload form with a submit button. After the form is submitted the file is uploaded and post-processing is started. The point is that the post-processing can take up to several minutes.
I would like to create some kind of asynchronous call of the post-processing function with showing information to the user.
So, the steps should be:
file form is submitted by user and upload is started
after the file is uploaded some information is shown to the user (e.g. "Processing..." or some loading-bar animation, etc.)
Meanwhile, the post-processing function is automatically started running in a background
After the post-processing function is finished the user is automatically redirected to another page
When i was searching the Internet I've found several examples but mostly only about asynchrounous call of functions, asynchrounous file upload (PageAsync method, etc.).
Any idea or techniques I should use or some tutorial?
Thanks in advance
That all depends on how fancy you want to get;
Meta-refresh that reloads the page until the background operation is finished
Some kind of ajax call that checks some resource for when the processing is done
HTML5 websockets. if supported, which it probably isn't.
Personally I would use the number 2. and use jQuery to poll the upload page every 500ms or something.
You can use AJAX
http://geekswithblogs.net/ranganh/archive/2008/04/01/file-upload-in-updatepanel-asp.net-ajax.aspx
http://vinayakshrestha.wordpress.com/2007/03/13/uploading-files-using-aspnet-ajax-extensions/
http://www.google.co.uk/search?sourceid=chrome&ie=UTF-8&q=upload+using+Ajax&qscrl=1#sclient=psy&hl=en&qscrl=1&source=hp&q=upload+using+Ajax+in+asp.net&aq=f&aqi=&aql=&oq=&pbx=1&fp=db9c4fafd449a821
The jquery/flash control uploadify will allow you to do this easily. They also provide a method for asynchronously calling a method on the event that the file upload completes as described in this comprehensive documentation.
I have looked at a lot of places for a good example, and this is the one I like the best so far.
It does not handle the uploading, but it does a fine job at showing real progress to the user and it is not difficult to implement
http://inov8.wordpress.com/2010/08/29/c-asp-net-creating-an-asynchronous-threaded-worker-process-manager-and-updatepanel-progress-monitor-control/

How to read html content of Ajax based site

I would like to know how the HTML source of ajax based sites can be read using HttpWebRequest / HttpWebResponse (That is reading the contents of a website at server side). The problem that I'm facing is that I'm unable to read parts of the webpage which uses Ajax or stuffs like UpdatePanel.
My application is in ASP.NET / C#, so can't think of using stuffs like Browser control or mshtml.dll since I would not be able to serve multiple requests.
Thanks in advance.
this is going to be difficult.
I know you said you don't want to use Browser control, but I'm going to say it anyway. You will most probably be better off using a Browser control. The reasons are as follow:
AJAX sites make multiple calls from the browser to the server to obtain the required view.
The multiple calls are being performed via JavaScript
The data returned from the server may be reformatted by JavaScript before being updated onto the view.
If you are going to do this using HttpWebXyz functions, you will have to do the following:
Make the relevant calls to get the initial page source.
Parse the page for JavaScript.
Evaluate/execute the JavaScript. This may include providing the relevant implementation for functions such as alert and making subsequent calls to the server.
Depending on the complexity of the AJAX site, you may want to reconsider using the browser control. Complex sites are easier process by the control. If the site is simple enough, you may survive parsing and executing the required JavaScript.
This example uses a deprecated class to parse JavaScript.
You may want to explore ICodeCompiler and its relevant classes for the new approach.
Good luck.

Audio/Video/Text chat in ASP.Net app

I need to develop a chat system in ASP.Net. I have gone through lots of SO question asked on similar topic, but did'nt find any one satisfactory. Is it possible to create it from scratch or do i need to go for some API's. My requirement is limited to my site users only, can say intranet based.
Please help me.
To make the text chat is one think that you can done with a simple table, everyone write on it, every one read time to time, and you show it to the page.
Here is an example http://www.codeproject.com/KB/ajax/ChatRoom.aspx
The Video/Audio chat is a complicate one. You can start with this example
http://www.codeproject.com/KB/IP/videochat.aspx
and you can read more here: how to work with videos in ASP.NET?
Text chat is relatively simple. It involves three tier architecture. 1) Javascript timer. 2) WCF Ajax Enabled web service or Generic Http Handler, 3) Data Storage (Preferably SQL).
1) On the page - sending: input text box + button (used to send). The button click event handler or the text box's key down (for enter key) and blur events would invoke a post (via JQuery, plain ol' JavaScript or whatever Javascript library you use) to the WCF service/Generic handler, sending the contents of the text box, along with the chartroom name, the addressee, and the recipient.
2) On the server: WCF Service/Generic Http handler receives the post and stores it in DB.
3) On the page - receiving: using JQuery for example, you would create a javascript timer on document ready (when the page loaded). On every timer's tick event you want to create a GET (or post) via your handy JavaScript framework (or Plain Javascript) to your WCF service/ Generic Handler requesting the latest records stored in the DB for that chatroom. Append the result received (assuming xml/html/json) to the Div or whatever element is used to display your "chats".
This is a very simplified chat in jquery/asp.net.
As far as audio-video is concerned, you have a few problems. 1) The browser itself has no means of interacting with the mike, speakers, and video camera, unless it uses a plugin. Moreover, browsers typically have no way of knowing how to decode a video stream (though some of the smarter ones have it built in... chrome, firefox). 3) Javascript has no way interacting with all the necessary hardware as it lives inside the browser.
All that said, you can use a plugin such as Flash or Silverlight, (that has built in access to the necessary hardware), or whatever. You will also have a conceptual dilemma with those as you have to simultaneously deal with 2 streams - one for coming in, another going out and displaying both. However it is possible.

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