public static async Task <TResult> TryAsyncResolve <TResult>(this IResolveFieldContext context, Func <IResolveFieldContext, Task <TResult> > resolve, Func <ExecutionErrors, Task <TResult> > error = null)
{
try
{
return(await resolve(context).ConfigureAwait(false));
}
catch (Exception ex)
{
if (error == null)
{
var er = new ExecutionError(ex.Message, ex);
er.AddLocation(context.FieldAst, context.Document);
er.Path = context.Path;
context.Errors.Add(er);
return(default);
public static void AddLocation(this ExecutionError error, AbstractNode abstractNode, Document document)
{
if (abstractNode != null)
{
if (document != null)
{
var location = new Location(new Source(document.OriginalQuery), abstractNode.SourceLocation.Start);
error.AddLocation(location.Line, location.Column);
}
else if (abstractNode.SourceLocation.Line > 0 && abstractNode.SourceLocation.Column > 0)
{
error.AddLocation(abstractNode.SourceLocation.Line, abstractNode.SourceLocation.Column);
}
}
}
private ResolveFieldResult <object> GenerateError(
ResolveFieldResult <object> 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);
}
/// <summary>
/// Resolve lists in a performant manor
/// </summary>
private async Task <List <object> > ResolveListFromData(ExecutionContext context, object source, IObjectGraphType parentType,
IGraphType graphType, Field field, IEnumerable <string> path)
{
var result = new List <object>();
var listInfo = graphType as ListGraphType;
var subType = listInfo?.ResolvedType as IObjectGraphType;
var data = source as IEnumerable;
var visitedFragments = new List <string>();
var subFields = CollectFields(context, subType, field.SelectionSet, null, visitedFragments);
if (data == null)
{
var error = new ExecutionError("User error: expected an IEnumerable list though did not find one.");
error.AddLocation(field, context.Document);
throw error;
}
var index = 0;
foreach (var node in data)
{
var currentPath = path.Concat(new[] { $"{index++}" });
if (subType != null)
{
var nodeResult = await ExecuteFieldsAsync(context, subType, node, subFields, currentPath)
.ConfigureAwait(false);
result.Add(nodeResult);
}
else
{
var nodeResult = await CompleteValueAsync(context, parentType, listInfo?.ResolvedType, field, node, currentPath)
.ConfigureAwait(false);
result.Add(nodeResult);
}
}
return(result);
}
/// <summary>
/// Resolve simple fields in a performant manor
/// </summary>
private static async Task <object> ResolveFieldFromDataAsync(ExecutionContext context, IObjectGraphType rootType, object source,
FieldType fieldType, Field field, IEnumerable <string> path)
{
object result = null;
try
{
if (fieldType.Resolver != null)
{
var rfc = new ResolveFieldContext(context, field, fieldType, source, rootType, null, path);
result = fieldType.Resolver.Resolve(rfc);
result = await UnwrapResultAsync(result)
.ConfigureAwait(false);
}
else
{
result = NameFieldResolver.Resolve(source, field.Name);
}
if (result != null)
{
var scalarType = fieldType.ResolvedType as ScalarGraphType;
result = scalarType?.Serialize(result);
}
}
catch (Exception exc)
{
var error = new ExecutionError($"Error trying to resolve {field.Name}.", exc);
error.AddLocation(field, context.Document);
error.Path = path.ToList();
context.Errors.Add(error);
// If there was an exception, the value of result cannot be trusted
result = null;
}
return(result);
}
public IObjectGraphType GetOperationRootType(Document document, ISchema schema, Operation operation)
{
IObjectGraphType type;
ExecutionError error;
switch (operation.OperationType)
{
case OperationType.Query:
type = schema.Query;
break;
case OperationType.Mutation:
type = schema.Mutation;
if (type == null)
{
error = new ExecutionError("Schema is not configured for mutations");
error.AddLocation(operation, document);
throw error;
}
break;
case OperationType.Subscription:
type = schema.Subscription;
if (type == null)
{
error = new ExecutionError("Schema is not configured for subscriptions");
error.AddLocation(operation, document);
throw error;
}
break;
default:
error = new ExecutionError("Can only execute queries, mutations and subscriptions.");
error.AddLocation(operation, document);
throw error;
}
return(type);
}
private void WriteErrorExtensions(ExecutionError error, JsonWriter writer, JsonSerializer serializer)
{
if (string.IsNullOrWhiteSpace(error.Code) && (error.Data == null || error.Data.Count == 0))
{
return;
}
writer.WritePropertyName("extensions");
writer.WriteStartObject();
if (!string.IsNullOrWhiteSpace(error.Code))
{
writer.WritePropertyName("code");
serializer.Serialize(writer, error.Code);
}
if (error.HasCodes)
{
writer.WritePropertyName("codes");
writer.WriteStartArray();
error.Codes.Apply(code => serializer.Serialize(writer, code));
writer.WriteEndArray();
}
if (error.Data?.Count > 0)
{
writer.WritePropertyName("data");
writer.WriteStartObject();
error.DataAsDictionary.Apply(entry =>
{
writer.WritePropertyName(entry.Key);
serializer.Serialize(writer, entry.Value);
});
writer.WriteEndObject();
}
writer.WriteEndObject();
}
public FieldType GetFieldDefinition(Document document, ISchema schema, IObjectGraphType parentType, Field field)
{
if (field.Name == SchemaIntrospection.SchemaMeta.Name && schema.Query == parentType)
{
return(SchemaIntrospection.SchemaMeta);
}
if (field.Name == SchemaIntrospection.TypeMeta.Name && schema.Query == parentType)
{
return(SchemaIntrospection.TypeMeta);
}
if (field.Name == SchemaIntrospection.TypeNameMeta.Name)
{
return(SchemaIntrospection.TypeNameMeta);
}
if (parentType == null)
{
var error = new ExecutionError($"Schema is not configured correctly to fetch {field.Name}. Are you missing a root type?");
error.AddLocation(field, document);
throw error;
}
return(parentType.Fields.FirstOrDefault(f => f.Name == field.Name));
}
public override void Add(ExecutionError error) => throw new NotSupportedException();
public async Task <object> CompleteValueAsync(ExecutionContext context, IObjectGraphType parentType, IGraphType fieldType, Field field, object result, IEnumerable <string> path)
{
var fieldName = field?.Name;
var nonNullType = fieldType as NonNullGraphType;
if (nonNullType != null)
{
var type = nonNullType.ResolvedType;
var completed = await CompleteValueAsync(context, parentType, type, field, result, path).ConfigureAwait(false);
if (completed == null)
{
var error = new ExecutionError("Cannot return null for non-null type. Field: {0}, Type: {1}!."
.ToFormat(fieldName, type.Name));
error.AddLocation(field, context.Document);
throw error;
}
return(completed);
}
if (result == null)
{
return(null);
}
if (fieldType is ScalarGraphType)
{
var scalarType = fieldType as ScalarGraphType;
var coercedValue = scalarType.Serialize(result);
return(coercedValue);
}
if (fieldType is ListGraphType)
{
var list = result as IEnumerable;
if (list == null)
{
var error = new ExecutionError("User error: expected an IEnumerable list though did not find one.");
error.AddLocation(field, context.Document);
throw error;
}
var listType = fieldType as ListGraphType;
var itemType = listType.ResolvedType;
var results = await list
.MapAsync(async (index, item) =>
await CompleteValueAsync(context, parentType, itemType, field, item, path.Concat(new[] { $"{index}" })).ConfigureAwait(false))
.ConfigureAwait(false);
return(results);
}
var objectType = fieldType as IObjectGraphType;
if (fieldType is IAbstractGraphType)
{
var abstractType = fieldType as IAbstractGraphType;
objectType = abstractType.GetObjectType(result);
if (objectType == null)
{
var error = new ExecutionError(
$"Abstract type {abstractType.Name} must resolve to an Object type at " +
$"runtime for field {parentType.Name}.{fieldName} " +
$"with value {result}, received 'null'.");
error.AddLocation(field, context.Document);
throw error;
}
if (!abstractType.IsPossibleType(objectType))
{
var error = new ExecutionError(
"Runtime Object type \"{0}\" is not a possible type for \"{1}\""
.ToFormat(objectType, abstractType));
error.AddLocation(field, context.Document);
throw error;
}
}
if (objectType == null)
{
return(null);
}
if (objectType.IsTypeOf != null && !objectType.IsTypeOf(result))
{
var error = new ExecutionError(
"Expected value of type \"{0}\" but got: {1}."
.ToFormat(objectType, result));
error.AddLocation(field, context.Document);
throw error;
}
var subFields = new Dictionary <string, Field>();
var visitedFragments = new List <string>();
subFields = CollectFields(context, objectType, field?.SelectionSet, subFields, visitedFragments);
return(await ExecuteFieldsAsync(context, objectType, result, subFields, path).ConfigureAwait(false));
}
public async Task <object> CompleteValueAsync(ExecutionContext context, IGraphType fieldType, Fields fields, object result)
{
var field = fields != null?fields.FirstOrDefault() : null;
var fieldName = field != null ? field.Name : null;
var nonNullType = fieldType as NonNullGraphType;
if (nonNullType != null)
{
var type = nonNullType.ResolvedType;
var completed = await CompleteValueAsync(context, type, fields, result).ConfigureAwait(false);
if (completed == null)
{
var error = new ExecutionError("Cannot return null for non-null type. Field: {0}, Type: {1}!."
.ToFormat(fieldName, type.Name));
error.AddLocation(field, context.Document);
throw error;
}
return(completed);
}
if (result == null)
{
return(null);
}
if (fieldType is ScalarGraphType)
{
var scalarType = fieldType as ScalarGraphType;
var coercedValue = scalarType.Serialize(result);
return(coercedValue);
}
if (fieldType is ListGraphType)
{
var list = result as IEnumerable;
if (list == null)
{
var error = new ExecutionError("User error: expected an IEnumerable list though did not find one.");
error.AddLocation(field, context.Document);
throw error;
}
var listType = fieldType as ListGraphType;
var itemType = listType.ResolvedType;
var results = await list.MapAsync(async item => await CompleteValueAsync(context, itemType, fields, item).ConfigureAwait(false)).ConfigureAwait(false);
return(results);
}
var objectType = fieldType as IObjectGraphType;
if (fieldType is IAbstractGraphType)
{
var abstractType = fieldType as IAbstractGraphType;
objectType = abstractType.GetObjectType(result);
if (objectType != null && !abstractType.IsPossibleType(objectType))
{
var error = new ExecutionError(
"Runtime Object type \"{0}\" is not a possible type for \"{1}\""
.ToFormat(objectType, abstractType));
error.AddLocation(field, context.Document);
throw error;
}
}
if (objectType == null)
{
return(null);
}
if (objectType.IsTypeOf != null && !objectType.IsTypeOf(result))
{
var error = new ExecutionError(
"Expected value of type \"{0}\" but got: {1}."
.ToFormat(objectType, result));
error.AddLocation(field, context.Document);
throw error;
}
var subFields = new Dictionary <string, Fields>();
var visitedFragments = new List <string>();
fields.Apply(f =>
{
subFields = CollectFields(context, objectType, f.SelectionSet, subFields, visitedFragments);
});
return(await ExecuteFieldsAsync(context, objectType, result, subFields).ConfigureAwait(false));
}
public async Task <ResolveFieldResult <object> > ResolveFieldAsync(ExecutionContext context, IObjectGraphType parentType, object source, Fields fields)
{
context.CancellationToken.ThrowIfCancellationRequested();
var resolveResult = new ResolveFieldResult <object>
{
Skip = false
};
var field = fields.First();
var fieldDefinition = GetFieldDefinition(context.Schema, parentType, field);
if (fieldDefinition == null)
{
resolveResult.Skip = true;
return(resolveResult);
}
var arguments = GetArgumentValues(context.Schema, fieldDefinition.Arguments, field.Arguments, context.Variables);
try
{
var resolveContext = new ResolveFieldContext();
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;
var resolver = fieldDefinition.Resolver ?? new NameFieldResolver();
var result = resolver.Resolve(resolveContext);
if (result is Task)
{
var task = result as Task;
await task.ConfigureAwait(false);
result = task.GetProperyValue("Result");
}
resolveResult.Value =
await CompleteValueAsync(context, fieldDefinition.ResolvedType, fields, result).ConfigureAwait(false);
return(resolveResult);
}
catch (Exception exc)
{
var error = new ExecutionError("Error trying to resolve {0}.".ToFormat(field.Name), exc);
error.AddLocation(field, context.Document);
context.Errors.Add(error);
resolveResult.Skip = false;
return(resolveResult);
}
}
public async Task <ResolveFieldResult <object> > ResolveField(ExecutionContext context, ObjectGraphType parentType, object source, Fields fields)
{
context.CancellationToken.ThrowIfCancellationRequested();
var resolveResult = new ResolveFieldResult <object>
{
Skip = false
};
var field = fields.First();
var fieldDefinition = GetFieldDefinition(context.Schema, parentType, field);
if (fieldDefinition == null)
{
resolveResult.Skip = true;
return(resolveResult);
}
var arguments = GetArgumentValues(context.Schema, fieldDefinition.Arguments, field.Arguments, context.Variables);
Func <ResolveFieldContext, object> defaultResolve =
ctx => ctx.Source != null
? GetProperyValue(ctx.Source, ctx.FieldAst.Name)
: null;
try
{
var resolveContext = new ResolveFieldContext();
resolveContext.FieldName = field.Name;
resolveContext.FieldAst = field;
resolveContext.FieldDefinition = fieldDefinition;
resolveContext.ReturnType = context.Schema.FindType(fieldDefinition.Type);
resolveContext.ParentType = parentType;
resolveContext.Arguments = arguments;
resolveContext.Source = source;
resolveContext.Schema = context.Schema;
resolveContext.Fragments = context.Fragments;
resolveContext.RootValue = context.RootValue;
resolveContext.Operation = context.Operation;
resolveContext.Variables = context.Variables;
resolveContext.CancellationToken = context.CancellationToken;
var resolve = fieldDefinition.Resolve ?? defaultResolve;
var result = resolve(resolveContext);
if (result is Task)
{
var task = result as Task;
await task;
result = GetProperyValue(task, "Result");
}
if (parentType is __Field && result is Type)
{
result = context.Schema.FindType(result as Type);
}
resolveResult.Value = await CompleteValue(context, context.Schema.FindType(fieldDefinition.Type), fields, result);
return(resolveResult);
}
catch (Exception exc)
{
var error = new ExecutionError("Error trying to resolve {0}.".ToFormat(field.Name), exc);
error.AddLocation(field.SourceLocation.Line, field.SourceLocation.Column);
context.Errors.Add(error);
resolveResult.Skip = false;
return(resolveResult);
}
}
/// <summary>
/// Adds the specified error to <see cref="Errors"/>.
/// </summary>
/// <returns>Reference to this.</returns>
public ExecutionResult AddError(ExecutionError error)
{
(Errors ??= new ExecutionErrors()).Add(error);
return(this);
}