CODEWITHSUNDEEP
windows-phone-8httpwebrequestwindows-phone.net-4.5
NullPointer
NullPointer

Reputation: 2184

Getting WP8 web requests to be synchronous

I am trying to port some code from a Windows form application to WP8, and have run into some issues regarding asynchronous calls. The basic idea is to do some UAG authentication. In the Windows form code, I do a GET on the portal homepage and wait for the cookies. I then pass these cookies into a POST request to the validation URL the UAG server. It all works fine in the form, since all the steps are sequential and synchronous.

Now, when I started porting this to WP8, first thing I noticed was that GetResponse() wasn't available, instead I had to use BeginGetResponse(), which is asynchronous and calls a callback function. This is no good for me, since I need to ensure this step finishes before I do the POST

My Windows form code looks like this (taken from http://usingnat.net/sharepoint/2011/2/23/how-to-programmatically-authenticate-to-uag-protected-sharep.html):

 private void Connect()
        {
            HttpWebRequest request = (HttpWebRequest)WebRequest.Create(this.Url);
            request.CookieContainer = new CookieContainer();
            request.UserAgent = this.UserAgent;
    using (HttpWebResponse response = (HttpWebResponse)request.GetResponse())
            {
                //Get the UAG generated cookies from the response
                this.Cookies = response.Cookies;
            }
       }

private void ValidateCredentials()
        {
        //Some code to construct the headers goes here...
       HttpWebRequest postRequest = (HttpWebRequest)WebRequest.Create(this.ValidationUrl);
       postRequest.ContentType = "application/x-www-form-urlencoded";
       postRequest.CookieContainer = new CookieContainer();
       foreach (Cookie cookie in this.Cookies)
        {
           postRequest.CookieContainer.Add(cookie);
        }
      postRequest.Method = "POST";
      postRequest.AllowAutoRedirect = true;

      using (Stream newStream = postRequest.GetRequestStream())
      {
          newStream.Write(data, 0, data.Length);
      }
      using (HttpWebResponse response = (HttpWebResponse)postRequest.GetResponse())
      {
          this.Cookies = response.Cookies;
      }

public CookieCollection Authenticate()
        {
            this.Connect();
            this.ValidateCredentials();
            return this.Cookies;
        }

The thing is this code relies on synchronous operation (first call Connect(), then ValidateCredentials() ), and it seems WP8 does not support that for Web requests. I could combine the two functions into one, but that won't solve my problem fully since later on this needs to be expanded to access resources behind the UAG, so it would need a modular design.

Is there a way to "force" synchronization?

Thanks

Upvotes: 1

Views: 816

Answers (1)

Alaa Masoud
Alaa Masoud

Reputation: 7135

You can still continue your steps in the call back function using the asynchronous model. Or you can use the new HttpClient which can be used with the await keyword so you can program your stuff in a synchronous way.

You can get HttpClient through nuget

install-package Microsoft.Net.Http

Upvotes: 1

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