Function buildViewUnionTypeData

codegen/service/service_data.go:1181–1213

buildViewUnionTypeData creates the data needed to generate a sum-type union in the views package. Field types are computed using the view scope and are always emitted unqualified so they refer to the view-local projected types.

(u *expr.Union, scope *codegen.NameScope, loc *codegen.Location)

// in the views package. Field types are computed using the view scope and are
// always emitted unqualified so they refer to the view-local projected types.
func buildViewUnionTypeData(u *expr.Union, scope *codegen.NameScope, loc *codegen.Location) *UnionTypeData {
	att := &expr.AttributeExpr{Type: u}
	name := scope.GoTypeName(att)
	kindName := scope.Unique(name + "Kind")

	fields := make([]*UnionFieldData, len(u.Values))
	for i, nat := range u.Values {
		fieldName := codegen.Goify(nat.Name, true)
		fieldType := scope.GoTypeRef(nat.Attribute)
		primitiveAliasType, hasPrimitiveAlias := primitiveAliasGoType(nat.Attribute.Type)
		_, isUserType := nat.Attribute.Type.(expr.UserType)
		emitPrimitiveAlias := hasPrimitiveAlias && !isUserType
		kindConst := kindName + codegen.Goify(nat.Name, true)
		fields[i] = &UnionFieldData{
			Name:               nat.Name,
			KindConst:          kindConst,
			FieldName:          fieldName,
			FieldType:          fieldType,
			EmitPrimitiveAlias: emitPrimitiveAlias,
			PrimitiveAliasType: primitiveAliasType,
			TypeTag:            nat.Name,
		}
	}

	return &UnionTypeData{
		Name:     name,
		KindName: kindName,
		Fields:   fields,
		Loc:      loc,
		TypeKey:  u.GetTypeKey(),
		ValueKey: u.GetValueKey(),
	}
}

// sortedNamedAttributes returns object fields sorted by attribute name.
// Union naming uses NameScope uniqueness, so callers that discover unions while