(C# UWP/WinRT) Paging User Photos with Cursor

Demonstrates how to iterate over the pages of user photos using a cursor.

Chilkat Universal Windows Platform (UWP) / WinRT Downloads Chilkat for the Universal Windows Platform (UWP)

// This example requires the Chilkat API to have been previously unlocked.
// See Global Unlock Sample for sample code.

// This example assumes a previously obtained an access token
Chilkat.OAuth2 oauth2 = new Chilkat.OAuth2();
oauth2.AccessToken = "FACEBOOK-ACCESS-TOKEN";

Chilkat.Rest rest = new Chilkat.Rest();

// Connect to Facebook.
bool success = await rest.ConnectAsync("graph.facebook.com",443,true,true);
if (success != true) {
    Debug.WriteLine(rest.LastErrorText);
    return;
}

// Provide the authentication credentials (i.e. the access key)
rest.SetAuthOAuth2(oauth2);

// Indicate that we only want the photos the user has personally uploaded.
rest.AddQueryParam("type","uploaded");

// We could limit the number of photos per page using the "limit" field.
rest.AddQueryParam("limit","20");

// Get the 1st page of photos. (Not the actual image data, but the information about each photo.)
// See https://developers.facebook.com/docs/graph-api/reference/user/photos/ for more information.
string responseJson = await rest.FullRequestNoBodyAsync("GET","/v2.7/me/photos");
if (rest.LastMethodSuccess != true) {
    Debug.WriteLine(rest.LastErrorText);
    return;
}

Chilkat.JsonObject json = new Chilkat.JsonObject();
json.EmitCompact = false;
json.Load(responseJson);
Debug.WriteLine(json.Emit());

// 
// See Parsing the Facebook User Photos for code showing how to parse the JSON photos content.
// 

// Get the "after" cursor.
string afterCursor = json.StringOf("paging.cursors.after");
while (json.LastMethodSuccess == true) {

    Debug.WriteLine("after cursor: " + afterCursor);

    // Prepare for getting the next page of photos.
    // We can continue using the same REST object.
    // If already connected, we'll continue using the existing connection.
    // Otherwise, a new connection will automatically be made if needed.
    rest.ClearAllQueryParams();
    rest.AddQueryParam("type","uploaded");
    rest.AddQueryParam("limit","20");
    rest.AddQueryParam("after",afterCursor);

    responseJson = await rest.FullRequestNoBodyAsync("GET","/v2.7/me/photos");
    if (rest.LastMethodSuccess != true) {
        Debug.WriteLine(rest.LastErrorText);
        return;
    }

    json.Load(responseJson);
    // See Parsing the Facebook User Photos for code showing how to parse the JSON photos content.

    Debug.WriteLine(json.Emit());

    // Get the cursor for the next page.
    afterCursor = json.StringOf("paging.cursors.after");
}

Debug.WriteLine("No more pages of photos.");