Eric lippert - Amazon Web Services

whose timeline we’ll search for images
- A Submit button to post the screen name to the server
- A series of divs that will be laid out dynamically with the help
of CSS.
The markup to achieve this is quite simple and shown below:
@using (Html.BeginForm(“Index”, “Home”, FormMethod.
Post))
{
Get Recent Tweets by
}
@foreach (var item in Model)
{
if (!string.IsNullOrEmpty(item.MediaUrl))
{
}
}
The Controller and Hooking up with Twitter
To keep the example simple, we will cut some corners here and
instead of splitting our implementation up into the standard
multiple layers, we’ll build a ‘fat controller’ instead.
Step 8: Add a new Empty MVC Controller called HomeController
OAuth Recap
b. LinqToTwitter will check the SessionStateCredential store to
see if it has a valid credential. If not, it will automatically redirect
the user to Twitter’s website for Authentication. Once the user has
authenticated and provided permissions for our App to access
their Twitter account, we’ll get re-directed back to our application
(all this is handled transparently by LinqToTwitter).
c. We have not built ANY backend to store Twitter’s
Authentication Token or the user’s id, so every time our session
expires, we’ll have to Authenticate with Twitter again. This is just
to keep things simple, in a real world application you should store
the Authentication Token and reuse it till it gets revoked.
The Controller Implementation
The sole job for the Controller in our app is to return a list of
TweetViewModel objects that is then used to render the View.
Step 9: We start the Controller implementation by declaring the
following fields
private IOAuthCredentials credentials = new
SessionStateCredentials();
private MvcAuthorizer auth;
private TwitterContext twitterCtx;
All three types (or Interfaces) are defined in the LinqToTwitter
namespace. The first one is a SessionStateCredentials() instance
is the container for the Twitter provided authentication token. It’s
valid once user has approved our app to connect to Twitter.
The MvcAuthorizer takes care of the checking if the credentials
from above are valid and if not, redirects to Twitter, intercepts the
login success and stores the credentials in the Session.
TwitterContext is like a DB Context, as in it’s the library used for
querying Twitter just as if it were a database.
Before we get into the Controller implementation, a quick recap of
how we’ll use LinqToTwitter:
a. LinqToTwitter will require a ConsumerKey and ConsumerSecret
for our application. We have to get this from http://dev.twitter.com
. You can refer to our previous editions to see how we can create
an application for ourselves on Twitter. Once you have the keys,
add them to the appSetting section in the web.config as follows:
Step 10: With the field initialization done, we are ready to get
data from Twitter and send it to the Index View. Core of the code is
in the GetTweets method.
private ActionResult GetTweets(string screenName)
{
if (credentials.ConsumerKey == null || credentials.
ConsumerSecret == null)
{
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