public async Task ExecuteAsync()
{
if (!ParseBuildRequest())
{
return;
}
AssignRequestOperation();
if (_requestContext.Failed)
{
return;
}
// signal to prepare/deserialize variables; in http/web scenario, we cannot parse variables immediately -
// we do not know variable types yet. Now that we have parsed and prepared query, we have var types;
// we fire this event, parent GraphQLHttpServer will handle it and deserializer variables.
_server.Events.OnRequestPrepared(_requestContext);
BuildOperationVariables();
if (_requestContext.Failed)
{
return;
}
BuildDirectiveContexts();
var opMapping = _requestContext.Operation.OperationTypeDef.Mappings[0];
var topScope = new OutputObjectScope(new RequestPath(), null, opMapping);
_requestContext.Response.Data = topScope;
await ExecuteOperationAsync(_requestContext.Operation, topScope);
}
private async Task ExecuteOperationAsync(GraphQLOperation op, OutputObjectScope topScope)
{
var mappedTopSubset = op.SelectionSubset.MappedSubSets[0];
var topMappedItems = mappedTopSubset.MappedItems;
var parallel = _parallelQueryEnabled && op.OperationType == OperationType.Query &&
op.SelectionSubset.Items.Count > 1;
var executers = new List <OperationFieldExecuter>();
foreach (var mappedItem in topMappedItems)
{
switch (mappedItem)
{
case MappedFragmentSpread mfs:
_requestContext.AddInputError($"Top selection items may not be fragments", mfs.Spread);
return;
case MappedSelectionField mappedField:
var opExecuter = new OperationFieldExecuter(_requestContext, mappedField, topScope);
executers.Add(opExecuter);
break;
}
}
if (parallel)
{
await ExecuteAllParallel(executers);
}
else
{
await ExecuteAllNonParallel(executers);
}
// Save results from op fields into top scope; we do it here, after all threads finished, to avoid concurrency issues
// and preserve output field order
foreach (var ex in executers)
{
topScope.SetValue(ex.ResultKey, ex.Result);
}
}
