/// <summary>
/// Constructor for a new page to an existing paged query.
/// </summary>
/// <param name="newItems"></param>
public PCOApiQueryResult(PCOApiQueryResult existingResults, List <DataItem> includedItems)
{
Items = existingResults.Items;
IncludedItems = existingResults.IncludedItems;
MergeIncludedItems(includedItems);
}
/// <summary>
/// Gets the results of an API query for the specified API end point.
/// </summary>
/// <param name="apiEndPoint">The API end point.</param>
/// <param name="apiRequestOptions">An optional collection of request options.</param>
/// <param name="modifiedSince">The modified since.</param>
/// <returns></returns>
private static PCOApiQueryResult GetAPIQuery(string apiEndPoint, Dictionary <string, string> apiRequestOptions = null, DateTime?modifiedSince = null, PCOApiQueryResult existingResults = null)
{
if (modifiedSince.HasValue && apiRequestOptions != null)
{
// Add a parameter to sort records by last update, descending.
apiRequestOptions.Add("order", "-updated_at");
}
string result = ApiGet(apiEndPoint, apiRequestOptions);
if (result.IsNullOrWhiteSpace())
{
return(null);
}
var itemsResult = JsonConvert.DeserializeObject <QueryItems>(result);
if (itemsResult == null)
{
PCOApi.ErrorMessage = $"Error: Unable to deserialize result retrieved from { apiEndPoint }.";
throw new Exception(PCOApi.ErrorMessage);
}
PCOApiQueryResult queryResult;
if (existingResults != null)
{
queryResult = new PCOApiQueryResult(existingResults, itemsResult.IncludedItems);
}
else
{
queryResult = new PCOApiQueryResult(itemsResult.IncludedItems);
}
// Loop through each item in the results
var continuePaging = true;
foreach (var itemResult in itemsResult.Data)
{
// If we're only looking for records updated after last update, and this record is older, stop processing
DateTime?recordUpdatedAt = (itemResult.Item.updated_at ?? itemResult.Item.created_at);
if (modifiedSince.HasValue && recordUpdatedAt.HasValue && recordUpdatedAt.Value <= modifiedSince.Value)
{
continuePaging = false;
break;
}
queryResult.Items.Add(itemResult);
}
// If there are more page, and we should be paging
string nextEndPoint = itemsResult.Links != null && itemsResult.Links.Next != null ? itemsResult.Links.Next : string.Empty;
if (nextEndPoint.IsNotNullOrWhitespace() && continuePaging)
{
nextEndPoint = nextEndPoint.Substring(ApiBaseUrl.Length);
// Get the next page of results by doing a recursive call to this same method.
// Note that nextEndPoint is supplied without the options dictionary, as those should already be specified in the result from PCO.
return(GetAPIQuery(nextEndPoint, null, modifiedSince, queryResult));
}
return(queryResult);
}
