/// <summary>
/// Retrieve a <see cref="IAsyncEnumerable{T}"/> using a SOQL query. Batches will be retrieved asynchronously.
/// <para>When using the iterator, the initial result batch will be returned as soon as it is received. The additional result batches will be retrieved only as needed.</para>
/// </summary>
/// <param name="queryString">SOQL query string, without any URL escaping/encoding</param>
/// <param name="queryAll">Optional. True if deleted records are to be included.await Defaults to false.</param>
/// <param name="batchSize">Optional. Size of result batches between 200 and 2000</param>
/// <param name="cancellationToken">Optional. Cancellation token</param>
/// <returns><see cref="IAsyncEnumerable{T}"/> of results</returns>
public async IAsyncEnumerable <T> QueryAsync <T>(string queryString, bool queryAll = false, int?batchSize = null, [EnumeratorCancellation] CancellationToken cancellationToken = default)
{
Dictionary <string, string> headers = new Dictionary <string, string>();
// Add call options
Dictionary <string, string> callOptions = HeaderFormatter.SforceCallOptions(ClientName);
headers.AddRange(callOptions);
// Add query options headers if batch size specified
if (batchSize.HasValue)
{
Dictionary <string, string> queryOptions = HeaderFormatter.SforceQueryOptions(batchSize.Value);
headers.AddRange(queryOptions);
}
var jsonClient = new JsonClient(AccessToken, _httpClient);
var nextRecordsUri = UriFormatter.Query(InstanceUrl, ApiVersion, queryString, queryAll);
bool hasMoreRecords = true;
while (hasMoreRecords)
{
var qr = await jsonClient.HttpGetAsync <QueryResult <T> >(nextRecordsUri, headers);
#if DEBUG
Debug.WriteLine($"Got query resuts, {qr.TotalSize} totalSize, {qr.Records.Count} in this batch, final batch: {qr.Done}");
#endif
if (!string.IsNullOrEmpty(qr.NextRecordsUrl))
{
nextRecordsUri = new Uri(new Uri(InstanceUrl), qr.NextRecordsUrl);
hasMoreRecords = true;
}
else
{
// Normally if a query has remaining batches, NextRecordsUrl will have a value, and Done will be false.
// In case of some unforseen error, consider the results done if we're missing the NextRecordsURL
hasMoreRecords = false;
}
foreach (T record in qr.Records)
{
yield return(record);
}
}
}
/// <summary>
/// Retrieve a <see cref="IAsyncEnumerator{T}"/> using a SOQL query. Batches will be retrieved asynchronously.
/// <para>When using the iterator, the initial result batch will be returned as soon as it is received. The additional result batches will be retrieved only as needed.</para>
/// </summary>
/// <param name="queryString">SOQL query string, without any URL escaping/encoding</param>
/// <param name="queryAll">Optional. True if deleted records are to be included.await Defaults to false.</param>
/// <param name="batchSize">Optional. Size of result batches between 200 and 2000</param>
/// <returns><see cref="IAsyncEnumerator{T}"/> of results</returns>
public IAsyncEnumerator <T> QueryAsyncEnumerator <T>(string queryString, bool queryAll = false, int?batchSize = null)
{
Dictionary <string, string> headers = new Dictionary <string, string>();
//Add call options
Dictionary <string, string> callOptions = HeaderFormatter.SforceCallOptions(ClientName);
headers.AddRange(callOptions);
//Add query options headers if batch size specified
if (batchSize.HasValue)
{
Dictionary <string, string> queryOptions = HeaderFormatter.SforceQueryOptions(batchSize.Value);
headers.AddRange(queryOptions);
}
var jsonClient = new JsonClient(AccessToken, _httpClient);
// Enumerator on the current batch items
IEnumerator <T> currentBatchEnumerator = null;
var done = false;
var nextRecordsUri = UriFormatter.Query(InstanceUrl, ApiVersion, queryString, queryAll);
return(AsyncEnumerable.CreateEnumerator(MoveNextAsync, Current, Dispose));
async Task <bool> MoveNextAsync(CancellationToken token)
{
if (token.IsCancellationRequested)
{
return(false);
}
// If items remain in the current Batch enumerator, go to next item
if (currentBatchEnumerator?.MoveNext() == true)
{
return(true);
}
// if done, no more items.
if (done)
{
return(false);
}
// else : no enumerator or currentBatchEnumerator ended
// so get the next batch
var qr = await jsonClient.HttpGetAsync <QueryResult <T> >(nextRecordsUri, headers);
#if DEBUG
Debug.WriteLine($"Got query resuts, {qr.TotalSize} totalSize, {qr.Records.Count} in this batch, final batch: {qr.Done}");
#endif
currentBatchEnumerator = qr.Records.GetEnumerator();
if (!string.IsNullOrEmpty(qr.NextRecordsUrl))
{
nextRecordsUri = new Uri(new Uri(InstanceUrl), qr.NextRecordsUrl);
done = false;
}
else
{
//Normally if query has remaining batches, NextRecordsUrl will have a value, and Done will be false.
//In case of some unforseen error, flag the result as done if we're missing the NextRecordsURL
done = true;
}
return(currentBatchEnumerator.MoveNext());
}
T Current()
{
return(currentBatchEnumerator == null ? default(T) : currentBatchEnumerator.Current);
}
void Dispose()
{
currentBatchEnumerator?.Dispose();
jsonClient.Dispose();
}
}