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?
Basically I just want to "ping" this page, so it knows it needs to refresh.
thanks!
If you just want to call the remote page, you can use the WebRequest class.
http://msdn.microsoft.com/en-us/library/debx8sh9.aspx
WebRequest request = WebRequest.Create("http://my.domain.ext/page.ashx");
using(WebResponse response = request.GetResponse()) {
response.Close();
}
If you want to do more advanced stuff a webservice would be more appropriate.
You could have a flag set up in the database. That would turn this into a much simpler task.
If no alternative exists you can use the WebClient class:
using (var wc = new WebClient())
{
wc.DownloadString(address);
}
Related
i'm in a slideshow extender web service method and trying to get a stringfrom the request.QueryString that i got in page_load.
of course new myPage() won't do.
so what can i do?
thanks
You can store the querystring in the Session on page load and access it from your service when necessary.
You can store the applicable parts of the query string in a hidden field on the page and pass the values along as part of your service call.
If the querystring is still a part of the URL when you want to make the service call, you can extract the values from the url with javascript and pass them along.
I have ASP.NET MVC site with authentication dialog (login/password) that is accessible on every page. When user provides login/password post-back is initiated to special controller, not the same as the one generated the page with dialog.
I do some authentication stuff and wish to return user's browser to the same page request came from. I do the following (simplified):
protected ActionResult Authorize(string login, string password)
{
...
return Redirect(Request.UrlReferrer.AbsoluteUri);
}
what is the best practice to perform such action?
Thank you in advance!
In the default Membership of ASP.NET they simply use a returnUrl parameter in the query string. I find that this gets the job done quite well. It also allows me to bounce them to a different url if that is what the requirement is.
There is nothing wrong with the way you are doing it now, I just prefer the flexibility of the query string parameter.
We have a Flex client and a server that is using the Spring/Blazeds project.
After the user logs in and is authenticated, the spring security layer sends a redirect to a new URL which is where our main application is located.
However, within the flex client, I'm currently using HTTPService for the initial request and I get the redirected page sent back to me in its entirety.
How can I just get the URL so that I can use navigatetourl to get where the app to go where it needs to?
Any help would greatly be appreciated. Thanks!
One solution would be to include a token inside a comment block on the returned page, for instance:
<!-- redirectPage="http://localhost/new-location" -->
then check for it's presence inside the HTTPService result handler. The token's value could then be used in your call to navigateToURL.
Another solution would be to examine the HTTP response headers and extract the value of the "Location" header using ActionScript. Consider using the AS3 HTTP Client lib.
From the examples page http://code.google.com/p/as3httpclientlib/wiki/Examples To determine the 'Location' header from the response:
var client:HttpClient = new HttpClient();
var uri:URI = new URI("http://localhost/j_security_check");
client.listener.onStatus = function(event:HttpStatusEvent):void {
var response:HttpResponse = event.response;
// Headers are case insensitive
var redirectLocation:String = response.header.getValue("Location");
// call navigateToURL with redirectLocation
// ...
};
// include username and password in the request
client.post(uri);
NOTE: AS3 HTTP Client depends on AS3 Core and AS3 Crypto libs.
You can also simply use the URLLoader class, no need for external code. One of the events it dispatches is HTTPStatusEvent.HTTP_RESPONSE_STATUS. Just plug into that and retrieve the redirected url:
urlLoader.addEventListener(HTTPStatusEvent.HTTP_RESPONSE_STATUS, onHTTPResponseStatus);
private function onHTTPResponseStatus(event:HTTPStatusEvent):void
{
var responseURL:String = event.responseURL;
}
I am (successfully) using this code right now, so if it doesn't work for some reason, let me know.
In my asp.net mvc 2 app, I'm wondering about the best way to implement this:
For every incoming request I need to perform custom authorization before allowing the file to be served. (This is based on headers and contents of the querystring. If you're familiar with how Amazon S3 does rest authentication - exactly that).
I'd like to do this in the most perfomant way possible, which probably means as light a touch as possible, with IIS doing as much of the actual work as possible.
The service will need to handle GET requests, as well as writing new files coming in via POST/PUT requests.
The requests are for an abitrary file, so it could be:
GET http://storage.foo.com/bla/egg/foo18/something.bin
POST http://storage.foo.com/else.txt
Right now I've half implemented it using an IHttpHandler which handles all routes (with routes.RouteExistingFiles = true), but not sure if that's the best, or if I should be hooking into the lifecycle somewhere else?
I'm also interested in supporting partial downloads with the Range header. Using
response.TransmitFile(finalPath);
as I am now means I'll have to do that manually, which seems a bit lowlevel?
Many thanks for any pointers.
(IIS7)
I think having a custom handler in the middle that takes care of this is exactly how you should be doing it.
TransmitFile is the lightest-weight programmatic way to serve a file that I am aware of.
However, you might not need to write your own HttpHandler. You can use the MVC handler and just dedicate a controller action to the job. Something like:
http://storage.foo.com/Files/Download/SomeFileIdentifier
...routing to...
public FilesController
{
public ActionResult Download(string id)
{
//...some logic to authenticate and to get the local file path
return File(theLocalFilePath, mimeType);
}
}
The File() method of controller uses TransmitFile in the background, I believe.
(PS, If you want shorter URLs, do it via custom routes in global.asax.)
Is there a way to modify the current Session() variable using jQuery? If it involves deconstructing the ViewState then I'm not really interested. Just curious if there was some easy way to do it.
Thanks!
If you need to pass a per session property between jQuery and the server you could try using cookies instead.
Otherwise you'll have to create a custom handler (ashx) file or a WebMethod or similar that lets you access it with Ajax calls.
jQuery
$.get("http://somewhere/page.aspx",
{sessionVar: "something"},
function(data)
{
alert("Session(\"something\") = " + data);
}
);
page.aspx:
Response.Write(Session[Request.QueryString["sessionVar"]]);
That's with no error checking or anything...
Session is stored on the server and you can't access it from jQuery unless you make an ajax call and get the session details from server.
Other than the fact that both ViewState and Session helps developer maintain state in their web application, they have nothing to do with each other.
EDIT:
If you want to modify the session using Ajax. Create an HTTP handler SessionHelper.ashx. This session handler can take 'SessionVariableName' and 'SessionVariableValue' as Query String parameters and modify the session state on the server. You can call this handler from jQuery using $.ajax method.
Please keep in mind that if you expose an handler like that, you will have to protect it against misuse as any person can call the handler directly and modify the Session variables. [e.g. If you store User role/privileges in session, a hacker can modify this role/privileges through this handler.]