internal static Func <object, object, object> CreateSetValueFunc(Type itemType, string propertyPath)
{
var parameter = Expression.Parameter(itemType, "item");
Expression getter = BindingExpressionHelper.GenerateMemberExpression(propertyPath, parameter);
if (getter.NodeType == ExpressionType.MemberAccess)
{
MemberExpression memberExpression = (MemberExpression)getter;
PropertyInfo propertyInfo = (PropertyInfo)memberExpression.Member;
if (!propertyInfo.CanWrite)
{
return(null);
}
}
ParameterExpression valueExp = Expression.Parameter(getter.Type, "propertyValue");
BinaryExpression assignExp = Expression.Assign(getter, valueExp);
var lambda = Expression.Lambda(assignExp, parameter, valueExp);
var compiled = lambda.Compile();
var declaredActionMethod = typeof(BindingExpressionHelper).GetTypeInfo().GetDeclaredMethod("ToUntypedDoubleParamFunc");
var methodInfo = declaredActionMethod.MakeGenericMethod(itemType, lambda.Body.Type, lambda.Body.Type);
return((Func <object, object, object>)methodInfo.Invoke(null, new object[] { compiled }));
}
/// <summary>
/// Returns a function that will return the value of the property, specified by the provided propertyPath.
/// </summary>
/// <param name="itemType">The type of the instance which property will be returned.</param>
/// <param name="propertyPath">The path of the property which value will be returned.</param>
public static Func <object, object> CreateGetValueFunc(Type itemType, string propertyPath)
{
var parameter = Expression.Parameter(itemType, "item");
Expression getter = BindingExpressionHelper.GenerateMemberExpression(propertyPath, parameter);
var lambda = Expression.Lambda(getter, parameter);
var compiled = lambda.Compile();
var methodInfo = typeof(BindingExpressionHelper).GetTypeInfo()
.GetDeclaredMethod("ToUntypedSingleParamFunc")
.MakeGenericMethod(new[] { itemType, lambda.Body.Type });
return((Func <object, object>)methodInfo.Invoke(null, new object[] { compiled }));
}
internal static Action <object, object> CreateSetValueAction(Type itemType, string propertyPath)
{
var setValueFunc = BindingExpressionHelper.CreateSetValueFunc(itemType, propertyPath);
return(setValueFunc != null ? new Action <object, object>((item, propertyValue) => setValueFunc?.Invoke(item, propertyValue)) : null);
}
