private ResolveEventStreamResult GenerateError(
ResolveEventStreamResult resolveResult,
Field field,
ExecutionContext context,
Exception exc,
IEnumerable <string> path)
{
var error = new ExecutionError("Error trying to resolve {0}.".ToFormat(field.Name), exc);
error.AddLocation(field, context.Document);
error.Path = path;
context.Errors.Add(error);
resolveResult.Skip = false;
return(resolveResult);
}
private ResolveEventStreamResult ResolveEventStream(
ExecutionContext context,
IObjectGraphType parentType,
object source,
Field field,
IEnumerable <string> path)
{
context.CancellationToken.ThrowIfCancellationRequested();
var fieldPath = path?.ToList() ?? new List <string>();
var resolveResult = new ResolveEventStreamResult
{
Skip = false
};
if (!(GetFieldDefinition(context.Document, context.Schema, parentType, field) is EventStreamFieldType fieldDefinition))
{
resolveResult.Skip = true;
return(resolveResult);
}
var arguments = GetArgumentValues(
context.Schema,
fieldDefinition.Arguments,
field.Arguments,
context.Variables);
try
{
var resolveContext = new ResolveEventStreamContext();
resolveContext.FieldName = field.Name;
resolveContext.FieldAst = field;
resolveContext.FieldDefinition = fieldDefinition;
resolveContext.ReturnType = fieldDefinition.ResolvedType;
resolveContext.ParentType = parentType;
resolveContext.Arguments = arguments;
resolveContext.Source = source;
resolveContext.Schema = context.Schema;
resolveContext.Document = context.Document;
resolveContext.Fragments = context.Fragments;
resolveContext.RootValue = context.RootValue;
resolveContext.UserContext = context.UserContext;
resolveContext.Operation = context.Operation;
resolveContext.Variables = context.Variables;
resolveContext.CancellationToken = context.CancellationToken;
resolveContext.Metrics = context.Metrics;
resolveContext.Errors = context.Errors;
resolveContext.Path = fieldPath;
if (fieldDefinition.Subscriber == null)
{
return(GenerateError(resolveResult, field, context,
new InvalidOperationException($"Subscriber not set for field {field.Name}"),
fieldPath));
}
var result = fieldDefinition.Subscriber.Subscribe(resolveContext);
var valueTransformer = result
.SelectMany(async value =>
{
var fieldResolveResult = await ResolveFieldAsync(context, parentType, value, field, fieldPath);
return(new ExecutionResult
{
Data = fieldResolveResult.Value
});
})
.Catch <ExecutionResult, Exception>(exception =>
Observable.Return(
new ExecutionResult
{
Errors = new ExecutionErrors
{
new ExecutionError(
$"Could not subscribe to field '{field.Name}' in query '{context.Document.OriginalQuery}'",
exception)
{
Path = path
}
}
}));
resolveResult.Value = valueTransformer;
return(resolveResult);
}
catch (Exception exc)
{
return(GenerateError(resolveResult, field, context, exc, path));
}
}
