Expression GetConvertFromString(TypeNode targetType, Expression src, bool always) {
if (targetType == SystemTypes.String)
return src;// nothing to do!
if (targetType is EnumNode) {
// e.g. return (DayOfWeek)Enum.Parse(typeof(DayOfWeek),"Sunday");
Method method = SystemTypes.Enum.GetMethod(Identifier.For("Parse"), new TypeNode[2]{ SystemTypes.Type, SystemTypes.String});
UnaryExpression typeOfEnum = new UnaryExpression(new MemberBinding(null, targetType), NodeType.Typeof);
MethodCall call = new MethodCall(new MemberBinding(new MemberBinding(null, targetType), method),
new ExpressionList(new Expression[2]{typeOfEnum, src }), NodeType.Call, SystemTypes.Object);
return CastTo(call, targetType);
}
// See if it has a type converter.
Class converterClass = Checker.GetTypeConverter(targetType);
if (converterClass != null) {
TypeConverter converter = TypeDescriptor.GetConverter(targetType.GetRuntimeType());
if (converter != null) {
Type converterType = converter.GetType();
AssemblyNode converterAssembly = AssemblyNode.GetAssembly(converterType.Assembly, cache, false, true);
converterClass = converterAssembly.GetType(Identifier.For(converterType.Namespace), Identifier.For(converterType.Name)) as Class;
Expression e = tempChecker.GetConverterFromString(converter, converterClass, SystemTypes.String, src, SystemTypes.Object);
if (e != null) {
//Do I need to add namespace and assembly reference for type converter?
return CastTo(e, targetType);
}
}
}
if (always) {
// e.g. return PointArray.Parse("10,20 30,40 50,60");
Method method = targetType.GetImplicitCoercionFromMethod(SystemTypes.String);
if (method == null) {
method = targetType.GetMethod(Identifier.For("Parse"), new TypeNode[1]{ SystemTypes.String});
}
if (method != null) {
MemberBinding typeBinding = new MemberBinding(null, targetType);
MethodCall call = new MethodCall(new MemberBinding(typeBinding, method),
new ExpressionList(new Expression[1]{ src }), NodeType.Call, targetType );
return call;
}
}
return null;
}