private async Task ExecuteObjectsSelectionSubsetAsync(IList <OutputObjectScope> parentScopes,
ObjectTypeDef objTypeDef, SelectionSubset subSet)
{
var outItemSet = subSet.MappedItemSets.FirstOrDefault(fi => fi.ObjectTypeDef == objTypeDef);
var mappedFields = _requestContext.GetIncludedMappedFields(outItemSet);
// init scopes
foreach (var scope in parentScopes)
{
scope.Init(objTypeDef, mappedFields);
}
for (int fldIndex = 0; fldIndex < mappedFields.Count; fldIndex++)
{
var mappedField = mappedFields[fldIndex];
var returnsComplexType = mappedField.FieldDef.Flags.IsSet(FieldFlags.ReturnsComplexType);
var fieldContext = new FieldContext(_requestContext, this, mappedField, fldIndex, parentScopes);
foreach (var scope in fieldContext.AllParentScopes)
{
if (fieldContext.BatchResultWasSet && scope.HasValue(fldIndex))
{
continue;
}
fieldContext.CurrentScope = scope;
object result = null;
switch (mappedField.FieldDef.ExecutionType)
{
case FieldExecutionType.Reader:
result = InvokeFieldReader(fieldContext, fieldContext.CurrentScope.Entity);
break;
case FieldExecutionType.Resolver:
result = await InvokeResolverAsync(fieldContext);
break;
}
var outValue = fieldContext.ConvertToOuputValue(result);
if (!fieldContext.BatchResultWasSet)
{
scope.SetValue(fldIndex, outValue);
}
} //foreach scope
// if there are any non-null object-type results, add this field context to this special list
// to execute selection subsets in the next round.
if (returnsComplexType && fieldContext.AllResultScopes.Count > 0)
{
_executedObjectFieldContexts.Add(fieldContext);
}
} //foreach fldIndex
} //method
public async Task ExecuteOperationFieldAsync()
{
try {
var opFieldContext = new FieldContext(_requestContext, this, _operationField, _fieldIndex);
opFieldContext.CurrentScope = _parentScope;
var result = await InvokeResolverAsync(opFieldContext);
var opOutValue = opFieldContext.ConvertToOuputValue(result);
_parentScope.SetValue(_fieldIndex, opOutValue);
// for fields returning objects, save for further processing of results
if (opFieldContext.Flags.IsSet(FieldFlags.ReturnsComplexType))
{
_executedObjectFieldContexts.Add(opFieldContext);
}
// process object field results until no more
while (_executedObjectFieldContexts.Count > 0)
{
if (_requestContext.CancellationToken.IsCancellationRequested)
{
opFieldContext.ThrowRequestCancelled();
}
// save current list, create new one in the field
var oldFieldContexts = _executedObjectFieldContexts;
_executedObjectFieldContexts = new List <FieldContext>();
foreach (var fldCtx in oldFieldContexts)
{
await ExecuteFieldSelectionSubsetAsync(fldCtx);
}
}//while
} finally {
// notify resolvers about end request
if (_resolverInstances.Count > 0)
{
foreach (var resObj in _resolverInstances)
{
(resObj as IResolverClass)?.EndRequest(_requestContext);
}
}
}
}