private async Task <ExpandoObject> ProcessSubscription(
GraphQLSubscriptionType type,
IFieldCollector fieldCollector,
FieldScope scope)
{
var fields = fieldCollector.CollectFields(type, this.Operation.SelectionSet);
var field = fields.Single(); //only single subscription field allowed
var result = new ExpandoObject();
var resultDictionary = (IDictionary <string, object>)result;
await this.RegisterSubscription(
field.Value.Single(),
type,
this.ast,
scope);
resultDictionary.Add("subscriptionId", this.subscriptionId.Value);
resultDictionary.Add("clientId", this.clientId);
var returnObject = new ExpandoObject();
var returnObjectDictionary = (IDictionary <string, object>)returnObject;
returnObjectDictionary.Add("data", result);
if (scope.Errors.Any())
{
returnObjectDictionary.Add("errors", scope.Errors);
}
return(returnObject);
}
private async Task RegisterSubscription(
GraphQLFieldSelection fieldSelection,
GraphQLSubscriptionType type,
GraphQLDocument document,
FieldScope scope)
{
var fieldInfo = type.GetFieldInfo(fieldSelection.Name.Value) as GraphQLSubscriptionTypeFieldInfo;
Expression <Func <object, bool> > filter = null;
if (fieldInfo.Filter != null)
{
filter = entity => (bool)scope.InvokeWithArgumentsSync(
fieldSelection.Arguments.ToList(), fieldInfo.Filter, entity);
}
await type.EventBus.Subscribe(EventBusSubscription.Create(
fieldInfo.Channel,
this.clientId,
this.subscriptionId.Value,
this.Operation?.Name?.Value ?? "Anonymous",
this.variables,
filter,
this.ast));
}
public void Subscription(GraphQLSubscriptionType root)
{
this.SubscriptionType = root;
this.SubscriptionType.EventBus.OnMessageReceived += this.InvokeSubscriptionMessageReceived;
}
