/// <summary>
/// Returns strong typed page of data.
/// </summary>
/// <param name="pageIndex">Page number.</param>
/// <param name="pageSize">Size of page.</param>
/// <param name="cancellationToken">Cancellation token.</param>
/// <returns>Strong typed page of data.</returns>
public async Task <IEnumerable <T> > GetPagedItemsAsync(int pageIndex, int pageSize, CancellationToken cancellationToken = default(CancellationToken))
{
if (_isFirstCall)
{
var result = await _paginatedArray.FirstAsync();
return(ProcessResult(result));
}
else
{
if (cancellationToken.IsCancellationRequested)
{
return(null);
}
if (_paginatedArray.HasNext && (pageIndex < _maxPages))
{
var result = await _paginatedArray.NextAsync();
return(ProcessResult(result));
}
else
{
return(null);
}
}
}
private async void AddLikes(
IReadOnlyList <object> pages
)
{
int count = 0;
foreach (object page in pages)
{
Items.Add((MyFBPage)page);
if (count == 0)
{
count++;
PageGetter pg = new PageGetter();
pg.GetPageWithId(((MyFBPage)page).Id);
}
}
if (_likes.HasNext)
{
FBResult result = await _likes.NextAsync();
if (result.Succeeded)
{
IReadOnlyList <object> nextPages =
(IReadOnlyList <object>)result.Object;
AddLikes(nextPages);
}
}
else
{
DoneGetUserLikes();
}
}
/// <summary>
/// Helper method to process pages of results from underlying service instance.
/// </summary>
/// <typeparam name="T">Strong type of model.</typeparam>
/// <param name="results">List of results to process.</param>
/// <param name="maxRecords">Total upper limit of records to process.</param>
/// <param name="processedResults">Stores the processed results constrained by maxRecords.</param>
/// <returns>Task to support await of async call.</returns>
private async Task ProcessResultsAsync <T>(IReadOnlyList <object> results, int maxRecords, List <T> processedResults)
{
foreach (T result in results)
{
if (processedResults.Count < maxRecords)
{
processedResults.Add(result);
}
}
if (paginatedArray.HasNext && processedResults.Count < maxRecords)
{
var nextResult = await paginatedArray.NextAsync();
if (nextResult.Succeeded)
{
IReadOnlyList <object> nextResults = (IReadOnlyList <object>)nextResult.Object;
await ProcessResultsAsync <T>(nextResults, maxRecords, processedResults);
}
}
}
/// <summary>
/// Helper method to process pages of results from underlying service instance.
/// </summary>
/// <param name="results">List of results to process.</param>
/// <param name="maxRecords">Total upper limit of records to process.</param>
/// <returns>Task to support await of async call.</returns>
private async Task ProcessResultsAsync(IReadOnlyList <object> results, int maxRecords)
{
foreach (FacebookPost result in results)
{
if (queryResults.Count < maxRecords)
{
queryResults.Add(result);
}
}
if (paginatedArray.HasNext && queryResults.Count < maxRecords)
{
var nextResult = await paginatedArray.NextAsync();
if (nextResult.Succeeded)
{
IReadOnlyList <object> nextResults = (IReadOnlyList <object>)nextResult.Object;
await ProcessResultsAsync(nextResults, maxRecords);
}
}
}
internal static async Task PopulateUserPages()
{
Pages.Clear();
String graphPath = "me/accounts";
FBPaginatedArray fbPages = new FBPaginatedArray(graphPath, null, FBPage.Factory);
FBResult result = null;
do
{
if (result == null)
{
result = await fbPages.FirstAsync();
}
else
{
result = await fbPages.NextAsync();
}
if (result.Succeeded)
{
IReadOnlyList <object> pages = (IReadOnlyList <object>)result.Object;
foreach (var p in pages)
{
FBPage page = (FBPage)p;
if (page != null)
{
Pages.Add(page);
}
}
}
else
{
FBErrorHandler.HandleError(result);
}
} while (fbPages.HasNext);
}
