in codegen/config/binder.go [365:491]
func (b *Binder) TypeReference(schemaType *ast.Type, bindTarget types.Type) (ret *TypeReference, err error) {
if bindTarget != nil {
bindTarget = code.Unalias(bindTarget)
}
if innerType, ok := unwrapOmittable(bindTarget); ok {
if schemaType.NonNull {
return nil, fmt.Errorf("%s is wrapped with Omittable but non-null", schemaType.Name())
}
ref, err := b.TypeReference(schemaType, innerType)
if err != nil {
return nil, err
}
ref.IsOmittable = true
return ref, err
}
if !isValid(bindTarget) {
b.SawInvalid = true
return nil, fmt.Errorf("%s has an invalid type", schemaType.Name())
}
var pkgName, typeName string
def := b.schema.Types[schemaType.Name()]
defer func() {
if err == nil && ret != nil {
b.PushRef(ret)
}
}()
if len(b.cfg.Models[schemaType.Name()].Model) == 0 {
return nil, fmt.Errorf("%s was not found", schemaType.Name())
}
for _, model := range b.cfg.Models[schemaType.Name()].Model {
if model == "map[string]interface{}" {
if !isMap(bindTarget) {
continue
}
return &TypeReference{
Definition: def,
GQL: schemaType,
GO: MapType,
IsRoot: b.cfg.IsRoot(def),
}, nil
}
if model == "interface{}" {
if !isIntf(bindTarget) {
continue
}
return &TypeReference{
Definition: def,
GQL: schemaType,
GO: InterfaceType,
IsRoot: b.cfg.IsRoot(def),
}, nil
}
pkgName, typeName = code.PkgAndType(model)
if pkgName == "" {
return nil, fmt.Errorf("missing package name for %s", schemaType.Name())
}
ref := &TypeReference{
Definition: def,
GQL: schemaType,
IsRoot: b.cfg.IsRoot(def),
}
obj, err := b.FindObject(pkgName, typeName)
if err != nil {
return nil, err
}
t := code.Unalias(obj.Type())
if values := b.enumValues(def); len(values) > 0 {
err = b.enumReference(ref, obj, values)
if err != nil {
return nil, err
}
} else if fun, isFunc := obj.(*types.Func); isFunc {
ref.GO = code.Unalias(t.(*types.Signature).Params().At(0).Type())
ref.IsContext = code.Unalias(t.(*types.Signature).Results().At(0).Type()).String() == "github.com/99designs/gqlgen/graphql.ContextMarshaler"
ref.Marshaler = fun
ref.Unmarshaler = types.NewFunc(0, fun.Pkg(), "Unmarshal"+typeName, nil)
} else if hasMethod(t, "MarshalGQLContext") && hasMethod(t, "UnmarshalGQLContext") {
ref.GO = t
ref.IsContext = true
ref.IsMarshaler = true
} else if hasMethod(t, "MarshalGQL") && hasMethod(t, "UnmarshalGQL") {
ref.GO = t
ref.IsMarshaler = true
} else if underlying := basicUnderlying(t); def.IsLeafType() && underlying != nil && underlying.Kind() == types.String {
// TODO delete before v1. Backwards compatibility case for named types wrapping strings (see #595)
ref.GO = t
ref.CastType = underlying
underlyingRef, err := b.TypeReference(&ast.Type{NamedType: "String"}, nil)
if err != nil {
return nil, err
}
ref.Marshaler = underlyingRef.Marshaler
ref.Unmarshaler = underlyingRef.Unmarshaler
} else {
ref.GO = t
}
ref.Target = ref.GO
ref.GO = b.CopyModifiersFromAst(schemaType, ref.GO)
if bindTarget != nil {
if err = code.CompatibleTypes(ref.GO, bindTarget); err != nil {
continue
}
ref.GO = bindTarget
}
ref.PointersInUnmarshalInput = b.cfg.ReturnPointersInUnmarshalInput
return ref, nil
}
return nil, fmt.Errorf("%s is incompatible with %s", schemaType.Name(), bindTarget.String())
}