Linq to twitter wp8 implementation

Question

I’m trying to get Linq to twitter to work on a wp8 App, i’ve looked throughout the available documentation and was not able to figure this out, when trying the demos (which the author says works for wp8) i get errors. Im using the ApplicationOnlyAuthorizer, my intention is just to be able to read the public tweets (not be able to log in and send tweets).

MainPage.cs

public MainPage()
{
     this.InitializeComponent();
     UserTweetsWidget = new UserTweetsViewModel("xxxxxxxx", 20);
     this.DataContext = this;
}

TweetModel.cs

public class TweetModel
{
    public string ScreenName { get; set; }
    public string UserName { get; set; }
    public string Image { get; set; }
    public string Text { get; set; }
    public string PublicationDate { get; set; }
}

UserTweetsViewModel.cs

public class UserTweetsViewModel
{
    public string Label { get; set; }
    public ObservableCollection<TweetModel> Tweets { get; set; }

    private const string consumerKey = “xxxxxxx”;
    private const string consumerSecret = “xxxxxx”;
    private const string twitterAccessToken = “xxxxxxxxxxxxxxxxx”;
    private const string twitterAccessTokenSecret = “xxxxxxxxxx”;

    public UserTweetsViewModel(string userName, int count)
    {
        String _n= userName;
        int _c= count;
        InitializeAsync(_n, _c);
    }

    private async Task InitializeAsync(string userName, int count)
    {
        this.Label = string.Format("Tweets by @{0}", userName);
        Tweets = await GetTwitterUserTimeLine(userName, count);
    }

    private async Task<ObservableCollection<TweetModel>> GetTwitterUserTimeLine(string userName, int count)
    {
        ObservableCollection<TweetModel> result = new ObservableCollection<TweetModel>();

        var auth = new ApplicationOnlyAuthorizer
        {
            CredentialStore = new InMemoryCredentialStore
            {
                ConsumerKey = consumerKey,
                ConsumerSecret = consumerSecret,
                OAuthToken= twitterAccessToken,
                OAuthTokenSecret= twitterAccessTokenSecret
            }
        };

        await auth.AuthorizeAsync();             
        TwitterContext twitterCtx = new TwitterContext(auth);

       var tweets = twitterCtx.Status.Where(tweet => tweet.ScreenName == userName && tweet.Type == StatusType.Home).Take(count).ToList();

        foreach (var item in tweets)
        {               
            TweetModel tweet = new TweetModel()
            {
                Text = item.Text,
                ScreenName = item.User.Name,
                UserName = "@" + item.ScreenName,
                PublicationDate = Convert.ToString(item.CreatedAt),
                Image = item.User.ProfileImageUrl                      
            };
            result.Add(tweet);
        }
        return result;
    }
}

Thanks, Bob

Answer 1

The problem, i think, is you aren't awaiting the AuthorizeAsync method.

First, you need to convert your GetTwitterUserTimeLine into an async method:

private async Task<ObservableCollection<TweetModel>> GetTwitterUserTimeLine(string userName, int count)

Then, you can call auth.AuthorizeAsync, awaiting the call:

await auth.AuthorizeAsync();

This way, the method waits until the authorization is completed, before continue execution.

UPDATE:

To call this method from your viewmodel, You can create a new method in the ViewModel, called InitializeAsync:

private async Task InitializeAsync()

In that method, call the GetTwitterUserTimeLine this way:

Tweets = await GetTwitterUserTimeLine(username, count);

Finally, you need to call the InitializeAsync Method from your viewmodel constructor, and it's going to work.

Hope this helps.