private async Task ExtractFieldAsync(ExecutionContext context, IObjectGraphType rootType, object source,
Field field, FieldType fieldType, ConcurrentDictionary <string, object> data, IEnumerable <string> path)
{
context.CancellationToken.ThrowIfCancellationRequested();
var name = field.Alias ?? field.Name;
if (data.ContainsKey(name))
{
return;
}
if (!ShouldIncludeNode(context, field.Directives))
{
return;
}
if (CanResolveFromData(field, fieldType))
{
var result = ResolveFieldFromData(context, rootType, source, fieldType, field, path);
data.TryAdd(name, result);
}
else
{
var result = await ResolveFieldAsync(context, rootType, source, field, path);
if (result.Skip)
{
return;
}
data.TryAdd(name, result.Value);
}
}
private bool CanResolveFromData(Field field, FieldType type)
{
if (field == null || type == null)
{
return(false);
}
if (type.Arguments != null &&
type.Arguments.Any())
{
return(false);
}
if (!(type.ResolvedType is ScalarGraphType))
{
return(false);
}
if (type.ResolvedType is NonNullGraphType)
{
return(false);
}
return(true);
}
/// <summary>
/// Resolve simple fields in a performant manor
/// </summary>
private static object ResolveFieldFromData(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);
}
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);
}
return(result);
}
public static void AddLocation(this ExecutionError error, Field field)
{
if (field != null)
{
error.AddLocation(field.SourceLocation.Line, field.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);
}
private void Field(IGraphType type, Field field, ValidationContext context)
{
if (type == null)
{
return;
}
if (type.IsLeafType())
{
if (field.SelectionSet != null && field.SelectionSet.Selections.Any())
{
var error = new ValidationError(context.OriginalQuery, "5.2.3", NoSubselectionAllowedMessage(field.Name, context.Print(type)), field.SelectionSet);
context.ReportError(error);
}
}
else if(field.SelectionSet == null || !field.SelectionSet.Selections.Any())
{
var error = new ValidationError(context.OriginalQuery, "5.2.3", RequiredSubselectionMessage(field.Name, context.Print(type)), field);
context.ReportError(error);
}
}
private IDictionary <string, Field> SubFieldsFor(ExecutionContext context, IGraphType fieldType, Field field)
{
if (!(fieldType is IObjectGraphType) || !field.SelectionSet.Selections.Any())
{
return(null);
}
var subFields = new Dictionary <string, Field>();
var visitedFragments = new List <string>();
var fields = CollectFields(context, fieldType, field.SelectionSet, subFields, visitedFragments);
return(fields);
}
public async Task <ResolveFieldResult <object> > ResolveFieldAsync(ExecutionContext context, IObjectGraphType parentType, object source, Field field, IEnumerable <string> path)
{
context.CancellationToken.ThrowIfCancellationRequested();
var fieldPath = path?.ToList() ?? new List <string>();
var resolveResult = new ResolveFieldResult <object>
{
Skip = false
};
var fieldDefinition = GetFieldDefinition(context.Document, 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;
resolveContext.Errors = context.Errors;
resolveContext.Path = fieldPath;
var subFields = SubFieldsFor(context, fieldDefinition.ResolvedType, field);
resolveContext.SubFields = subFields;
var resolver = fieldDefinition.Resolver ?? new NameFieldResolver();
var result = resolver.Resolve(resolveContext);
if (result is Task)
{
var task = result as Task;
if (task.IsFaulted)
{
var aggregateException = task.Exception;
var exception = aggregateException.InnerExceptions.Count == 1
? aggregateException.InnerException
: aggregateException;
return(GenerateError(resolveResult, field, context, exception, fieldPath));
}
await task.ConfigureAwait(false);
result = task.GetProperyValue("Result");
}
resolveResult.Value =
await CompleteValueAsync(context, parentType, fieldDefinition.ResolvedType, field, result, fieldPath).ConfigureAwait(false);
return(resolveResult);
}
catch (Exception exc)
{
return(GenerateError(resolveResult, field, context, exc, path));
}
}
public FieldType GetFieldDefinition(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);
}
return(parentType.Fields.FirstOrDefault(f => f.Name == field.Name));
}
public FieldType GetFieldDefinition(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;
}
return parentType.Fields.FirstOrDefault(f => f.Name == field.Name);
}
protected bool Equals(Field other)
{
return string.Equals(Name, other.Name) && string.Equals(Alias, other.Alias);
}
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 async Task <ResolveFieldResult <object> > ResolveFieldAsync(ExecutionContext context, IObjectGraphType parentType, object source, Field field, IEnumerable <string> path)
{
context.CancellationToken.ThrowIfCancellationRequested();
var fieldPath = path?.ToList() ?? new List <string>();
var resolveResult = new ResolveFieldResult <object>
{
Skip = false
};
var fieldDefinition = GetFieldDefinition(context.Document, 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
{
FieldName = field.Name,
FieldAst = field,
FieldDefinition = fieldDefinition,
ReturnType = fieldDefinition.ResolvedType,
ParentType = parentType,
Arguments = arguments,
Source = source,
Schema = context.Schema,
Document = context.Document,
Fragments = context.Fragments,
RootValue = context.RootValue,
UserContext = context.UserContext,
Operation = context.Operation,
Variables = context.Variables,
CancellationToken = context.CancellationToken,
Metrics = context.Metrics,
Errors = context.Errors,
Path = fieldPath
};
var subFields = SubFieldsFor(context, fieldDefinition.ResolvedType, field);
resolveContext.SubFields = subFields;
var resolver = fieldDefinition.Resolver ?? new NameFieldResolver();
var result = resolver.Resolve(resolveContext);
result = await UnwrapResultAsync(result)
.ConfigureAwait(false);
resolveResult.Value = await CompleteValueAsync(context, parentType, fieldDefinition.ResolvedType, field, result, fieldPath)
.ConfigureAwait(false);
return(resolveResult);
}
catch (Exception exc)
{
return(GenerateError(resolveResult, field, context, exc, path));
}
}
/// <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($"Error trying to resolve {field.Name}.", exc);
error.AddLocation(field, context.Document);
error.Path = path.ToList();
context.Errors.Add(error);
// If there was an exception, the value of result cannot be trusted
result = null;
}
return(result);
}
private ResolveEventStreamResult ResolveEventStream(
ExecutionContext context,
IObjectGraphType parentType,
object source,
Field field,
IEnumerable <string> path)
{
context.CancellationToken.ThrowIfCancellationRequested();
var fieldPath = path?.ToList() ?? new List <string>();
var resolveResult = new ResolveEventStreamResult
{
Skip = false
};
if (!(GetFieldDefinition(context.Document, context.Schema, parentType, field) is EventStreamFieldType fieldDefinition))
{
resolveResult.Skip = true;
return(resolveResult);
}
var arguments = GetArgumentValues(
context.Schema,
fieldDefinition.Arguments,
field.Arguments,
context.Variables);
try
{
var resolveContext = new ResolveEventStreamContext();
resolveContext.FieldName = field.Name;
resolveContext.FieldAst = field;
resolveContext.FieldDefinition = fieldDefinition;
resolveContext.ReturnType = fieldDefinition.ResolvedType;
resolveContext.ParentType = parentType;
resolveContext.Arguments = arguments;
resolveContext.Source = source;
resolveContext.Schema = context.Schema;
resolveContext.Document = context.Document;
resolveContext.Fragments = context.Fragments;
resolveContext.RootValue = context.RootValue;
resolveContext.UserContext = context.UserContext;
resolveContext.Operation = context.Operation;
resolveContext.Variables = context.Variables;
resolveContext.CancellationToken = context.CancellationToken;
resolveContext.Metrics = context.Metrics;
resolveContext.Errors = context.Errors;
resolveContext.Path = fieldPath;
if (fieldDefinition.Subscriber == null)
{
return(GenerateError(resolveResult, field, context,
new InvalidOperationException($"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));
}
}
private ResolveFieldResult<object> GenerateError(ResolveFieldResult<object> resolveResult, Field field, ExecutionContext context, 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 <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));
}
/// <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);
result.Add(nodeResult);
}
else
{
var nodeResult = await CompleteValueAsync(context, parentType, listInfo?.ResolvedType, field, node, currentPath).ConfigureAwait(false);
result.Add(nodeResult);
}
}
return(result);
}
private FieldType GetFieldDef(ISchema schema, GraphType parentType, Field field)
{
var name = field.Name;
if (name == SchemaIntrospection.SchemaMeta.Name
&& Equals(schema.Query, parentType))
{
return SchemaIntrospection.SchemaMeta;
}
if (name == SchemaIntrospection.TypeMeta.Name
&& Equals(schema.Query, parentType))
{
return SchemaIntrospection.TypeMeta;
}
if (name == SchemaIntrospection.TypeNameMeta.Name
&& (parentType is ObjectGraphType
|| parentType is InterfaceGraphType
|| parentType is UnionGraphType))
{
return SchemaIntrospection.TypeNameMeta;
}
if (parentType is ObjectGraphType || parentType is InterfaceGraphType)
{
return parentType.Fields.FirstOrDefault(x => x.Name == field.Name);
}
return null;
}
protected bool Equals(Field other)
{
return(string.Equals(Name, other.Name, StringComparison.InvariantCulture) && string.Equals(Alias, other.Alias, StringComparison.InvariantCulture));
}
