/// <summary>
/// Builds out this field template parsing out the required type declarations unions, nameing scheme etc. This method should be
/// overridden in any child classes for additional decalration requirements.
/// </summary>
protected override void ParseTemplateDefinition()
{
// ensure type extension right out of the gate
// the field can't be built otherwise
_typeAttrib = this.SingleAttributeOfTypeOrDefault <TypeExtensionAttribute>();
if (_typeAttrib == null)
{
return;
}
_sourceType = _typeAttrib.TypeToExtend;
base.ParseTemplateDefinition();
var returnType = GraphValidation.EliminateWrappersFromCoreType(this.DeclaredReturnType);
if (returnType != typeof(IGraphActionResult))
{
// inspect the return type, if its a valid dictionary extract the return type from the value
// and set the type modifiers and method type based on the value of each dictionary entry
if (_typeAttrib.ExecutionMode == FieldResolutionMode.Batch)
{
returnType = returnType.GetValueTypeOfDictionary();
this.ObjectType = GraphValidation.EliminateWrappersFromCoreType(returnType);
this.TypeExpression = GraphValidation.GenerateTypeExpression(returnType, this);
this.PossibleTypes.Insert(0, this.ObjectType);
}
}
}
/// <summary>
/// Parses the template contents according to the rules of the template.
/// </summary>
public virtual void Parse()
{
this.DeclaredArgumentType = this.Parameter.ParameterType;
this.ObjectType = GraphValidation.EliminateWrappersFromCoreType(this.Parameter.ParameterType);
// set the name
_fieldDeclaration = this.Parameter.SingleAttributeOrDefault <FromGraphQLAttribute>();
string name = null;
if (_fieldDeclaration != null)
{
name = _fieldDeclaration?.ArgumentName?.Trim();
}
if (string.IsNullOrWhiteSpace(name))
{
name = Constants.Routing.PARAMETER_META_NAME;
}
name = name.Replace(Constants.Routing.PARAMETER_META_NAME, this.Parameter.Name);
this.Route = new GraphArgumentFieldPath(this.Parent.Route, name);
this.Description = this.Parameter.SingleAttributeOrDefault <DescriptionAttribute>()?.Description?.Trim();
if (this.Parameter.HasDefaultValue && this.Parameter.DefaultValue != null)
{
// enums will present their default value as a raw int
if (this.ObjectType.IsEnum)
{
this.DefaultValue = Enum.ToObject(this.ObjectType, this.Parameter.DefaultValue);
}
else
{
this.DefaultValue = this.Parameter.DefaultValue;
}
}
// set appropriate meta data about this parameter for inclusion in the type system
this.TypeExpression = GraphValidation.GenerateTypeExpression(this.DeclaredArgumentType, this);
this.TypeExpression = this.TypeExpression.CloneTo(GraphTypeNames.ParseName(this.ObjectType, TypeKind.INPUT_OBJECT));
// when this argument accepts the same data type as the data returned by its owners target source type
// i.e. if the source data supplied to the field for resolution is the same as this argument
// then assume this argument is to contain the source data
// since the source data will be an OBJECT type (not INPUT_OBJECT) there is no way the user could have supplied it
if (this.IsSourceDataArgument())
{
this.ArgumentModifiers = this.ArgumentModifiers
| GraphArgumentModifiers.ParentFieldResult
| GraphArgumentModifiers.Internal;
}
}
public void GenerateTypeExpression(
Type type,
string expectedExpression,
bool definesDefaultValue,
GTW[] wrappers)
{
var mock = new Mock <IGraphTypeExpressionDeclaration>();
mock.Setup(x => x.HasDefaultValue).Returns(definesDefaultValue);
mock.Setup(x => x.TypeWrappers).Returns(wrappers);
var typeExpression = GraphValidation.GenerateTypeExpression(type, mock.Object);
Assert.AreEqual(expectedExpression, typeExpression.ToString());
}
/// <summary>
/// Validates the completed field context to ensure it is "correct" against the specification before finalizing its reslts.
/// </summary>
/// <param name="context">The context containing the resolved field.</param>
/// <returns><c>true</c> if the node is valid, <c>false</c> otherwise.</returns>
public override bool Execute(FieldValidationContext context)
{
var typeExpression = context.TypeExpression;
if (typeExpression.IsRequired && context.ResultData == null)
{
// 6.4.3 section 1c
this.ValidationError(
context,
$"Field '{context.FieldPath}' expected a non-null result but received {{null}}.");
context.DataItem.InvalidateResult();
}
// 6.4.3 section 2
if (context.ResultData == null)
{
return(true);
}
// 6.4.3 section 3, ensure an IEnumerable for a type expression that is a list
if (typeExpression.IsListOfItems && !GraphValidation.IsValidListType(context.ResultData.GetType()))
{
this.ValidationError(
context,
$"Field '{context.FieldPath}' was expected to return a list of items but instead returned a single item.");
context.DataItem.InvalidateResult();
return(true);
}
var graphType = context.Schema?.KnownTypes.FindGraphType(typeExpression?.TypeName);
if (graphType == null)
{
this.ValidationError(
context,
$"The graph type for field '{context.FieldPath}' ({typeExpression?.TypeName}) does not exist on the target schema. The field" +
$"cannot be properly evaluated.");
context.DataItem.InvalidateResult();
}
else if (!typeExpression.Matches(context.ResultData, graphType.ValidateObject))
{
// generate a valid, properly cased type expression reference for the data that was provided
var actualExpression = GraphValidation.GenerateTypeExpression(context.ResultData.GetType());
var coreType = GraphValidation.EliminateWrappersFromCoreType(context.ResultData.GetType());
var actualType = context.Schema.KnownTypes.FindGraphType(coreType);
if (actualType != null)
{
actualExpression = actualExpression.CloneTo(actualType.Name);
}
// 6.4.3 section 4 & 5
this.ValidationError(
context,
$"The resolved value for field '{context.FieldPath}' does not match the required type expression. " +
$"Expected {typeExpression} but got {actualExpression}.");
context.DataItem.InvalidateResult();
}
return(true);
}
/// <summary>
/// When overridden in a child class this method builds out the template according to its own individual requirements.
/// </summary>
protected override void ParseTemplateDefinition()
{
_fieldDeclaration = this.SingleAttributeOfTypeOrDefault <GraphFieldAttribute>();
// ------------------------------------
// Common Metadata
// ------------------------------------
this.Route = this.GenerateFieldPath();
this.Mode = _fieldDeclaration?.ExecutionMode ?? FieldResolutionMode.PerSourceItem;
this.Complexity = _fieldDeclaration?.Complexity;
this.Description = this.SingleAttributeOfTypeOrDefault <DescriptionAttribute>()?.Description;
var depreciated = this.SingleAttributeOfTypeOrDefault <DeprecatedAttribute>();
if (depreciated != null)
{
this.IsDeprecated = true;
this.DeprecationReason = depreciated.Reason?.Trim();
}
var objectType = GraphValidation.EliminateWrappersFromCoreType(this.DeclaredReturnType);
var typeExpression = GraphValidation.GenerateTypeExpression(this.DeclaredReturnType, this);
typeExpression = typeExpression.CloneTo(GraphTypeNames.ParseName(objectType, this.Parent.Kind));
// ------------------------------------
// Gather Possible Types and/or union definition
// ------------------------------------
this.BuildUnionProxyInstance();
if (this.UnionProxy != null)
{
this.PossibleTypes = new List <Type>(this.UnionProxy.Types);
}
else
{
this.PossibleTypes = new List <Type>();
// the possible types attribte is optional but expects taht the concrete types are added
// to the schema else where lest a runtime exception occurs of a missing graph type.
var typesAttrib = this.SingleAttributeOfTypeOrDefault <PossibleTypesAttribute>();
if (typesAttrib != null)
{
foreach (var type in typesAttrib.PossibleTypes)
{
this.PossibleTypes.Add(type);
}
}
// add any types decalred on the primary field declaration
if (_fieldDeclaration != null)
{
foreach (var type in _fieldDeclaration.Types)
{
var strippedType = GraphValidation.EliminateWrappersFromCoreType(type);
if (strippedType != null)
{
this.PossibleTypes.Add(strippedType);
}
}
}
if (objectType != null && !Validation.IsCastable <IGraphActionResult>(objectType) && GraphValidation.IsValidGraphType(objectType))
{
this.PossibleTypes.Insert(0, objectType);
}
}
this.PossibleTypes = this.PossibleTypes.Distinct().ToList();
// ------------------------------------
// Adjust the action result to the actual return type this field returns
// ------------------------------------
if (Validation.IsCastable <IGraphActionResult>(objectType))
{
if (this.UnionProxy != null)
{
// if a union was decalred preserve whatever modifer elements
// were decalred but alter the return type to object (a known common element among all members of the union)
objectType = typeof(object);
}
else if (_fieldDeclaration != null && _fieldDeclaration.Types.Count > 0)
{
objectType = _fieldDeclaration.Types[0];
typeExpression = GraphValidation.GenerateTypeExpression(objectType, this)
.CloneTo(GraphTypeNames.ParseName(objectType, this.Parent.Kind));
objectType = GraphValidation.EliminateWrappersFromCoreType(objectType);
}
else if (this.PossibleTypes.Count > 0)
{
objectType = this.PossibleTypes[0];
typeExpression = GraphValidation.GenerateTypeExpression(objectType, this)
.CloneTo(GraphTypeNames.ParseName(objectType, this.Parent.Kind));
objectType = GraphValidation.EliminateWrappersFromCoreType(objectType);
}
else
{
objectType = typeof(object);
}
}
this.ObjectType = objectType;
if (this.UnionProxy != null)
{
this.TypeExpression = typeExpression.CloneTo(this.UnionProxy.Name);
}
else
{
this.TypeExpression = typeExpression;
}
// ------------------------------------
// Async Requirements
// ------------------------------------
this.IsAsyncField = Validation.IsCastable <Task>(this.DeclaredReturnType);
// ------------------------------------
// Security Policies
// ------------------------------------
_securityPolicies = FieldSecurityGroup.FromAttributeCollection(this.AttributeProvider);
}
/// <summary>
/// Validates the completed field context to ensure it is "correct" against the specification before finalizing its reslts.
/// </summary>
/// <param name="context">The context containing the resolved field.</param>
/// <returns><c>true</c> if the node is valid, <c>false</c> otherwise.</returns>
public override bool Execute(FieldValidationContext context)
{
var dataObject = context.ResultData;
// 6.4.3 section 1c
// This is a quick short cut and customed error message for a common top-level null mismatch.
var dataItemTypeExpression = context.DataItem.TypeExpression;
if (dataItemTypeExpression.IsRequired && dataObject == null)
{
this.ValidationError(
context,
$"Field '{context.FieldPath}' expected a non-null result but received {{null}}.");
context.DataItem.InvalidateResult();
}
// 6.4.3 section 2
if (dataObject == null)
{
return(true);
}
// 6.4.3 section 3, ensure list type in the result object for a type expression that is a list.
// This is a quick short cut and customed error message for a common top-level list mismatch.
if (dataItemTypeExpression.IsListOfItems && !GraphValidation.IsValidListType(dataObject.GetType()))
{
this.ValidationError(
context,
$"Field '{context.FieldPath}' was expected to return a list of items but instead returned a single item.");
context.DataItem.InvalidateResult();
return(true);
}
var expectedGraphType = context.Schema?.KnownTypes.FindGraphType(context.Field);
if (expectedGraphType == null)
{
this.ValidationError(
context,
$"The graph type for field '{context.FieldPath}' ({dataItemTypeExpression?.TypeName}) does not exist on the target schema. The field" +
"cannot be properly evaluated.");
context.DataItem.InvalidateResult();
return(true);
}
// Perform a deep check of the meta-type chain (list and nullability wrappers) against the result data.
// For example, if the type expression is [[SomeType]] ensure the result object is List<List<T>> etc.)
// however, use the type name of the actual data object, not the graph type itself
// we only want to check the type expression wrappers in this step
var rootSourceType = GraphValidation.EliminateWrappersFromCoreType(dataObject.GetType());
var mangledTypeExpression = dataItemTypeExpression.CloneTo(rootSourceType.Name);
if (!mangledTypeExpression.Matches(dataObject))
{
// generate a valid, properly cased type expression reference for the data that was provided
var actualExpression = GraphValidation.GenerateTypeExpression(context.ResultData.GetType());
// Fake the type expression against the real graph type
// this step only validates the meta graph types the actual type may be different (but castable to the concrete
// type of the graphType). Don't confuse the user in this step.
actualExpression = actualExpression.CloneTo(expectedGraphType.Name);
// 6.4.3 section 4 & 5
this.ValidationError(
context,
$"The resolved value for field '{context.FieldPath}' does not match the required type expression. " +
$"Expected {dataItemTypeExpression} but got {actualExpression}.");
context.DataItem.InvalidateResult();
}
return(true);
}