public override Expression Visit(Expression node)
{
if (node != null)
{
var snExpr = _expressions[node];
if (snExpr.IsExecutable)
{
if (node.NodeType == ExpressionType.Constant)
{
return(node);
}
var x = DynamicExpression.Lambda(node);
var y = x.Compile();
var z = y.DynamicInvoke();
return(Expression.Constant(z));
}
}
return(base.Visit(node));
}
public static IHtmlContent EditorFor <TModel>(
this HtmlHelper <TModel> htmlHelper,
object instance,
string expression)
{
var tType = instance.GetType();
//TModel = typeof(instance);
htmlHelper.ViewContext.ViewData.Model = instance;
var lambda = DynamicExpression.Lambda(Expression.Property(Expression.Parameter(tType, "m"), expression));
var methods = typeof(HtmlHelper).GetMethods();
var method = methods.Where(x =>
{
var args = x.GetGenericArguments();
var parms = x.GetParameters();
return(args.Count() == 2 &&
args[0].Name == "TModel" &&
args[1].Name == "TValue" &&
x.Name == "EditorFor" &&
parms.Count() == 2 &&
parms[0].ParameterType.Name == "HtmlHelper`1" &&
parms[1].ParameterType.Name == "Expression`1");
}).First();
method = method.MakeGenericMethod(new[] { tType, lambda.Body.Type });
var htmlHelperType = typeof(HtmlHelper <>)
.MakeGenericType(tType);
var helper = htmlHelper;
return((IHtmlContent)method.Invoke(
helper,
new object[] { helper, lambda }
));
}
private static IQueryable ExpandQueryableOrderBy(IQueryable source, string[] statements)
{
var expression = source.Expression;
var parameter = Expression.Parameter(source.ElementType, String.Empty);
for (int idx = 0; idx < statements.Length; idx++)
{
bool isAscending = true;
// Try LINQ ascending/descending suffix
string memberReference = ParseStatement(statements[idx], out isAscending);
bool isFirstOrderBy = (idx == 0);
var methodName = (isFirstOrderBy ? "OrderBy" : "ThenBy") + (isAscending ? String.Empty : "Descending");
// Unravel nested property accesses
var memberElements = memberReference.Split('.');
Expression memberExpression = parameter;
foreach (string memberElement in memberElements)
{
if (string.IsNullOrEmpty(memberElement))
{
throw new ArgumentException(Strings.EntityDataSourceView_EmptyPropertyName);
}
memberExpression = Expression.Property(memberExpression, memberElement.Trim());
}
expression = Expression.Call(typeof(Queryable), methodName, new Type[] { source.ElementType, memberExpression.Type },
new Expression[] { expression, Expression.Quote(DynamicExpression.Lambda(memberExpression, parameter)) });
}
return(source.Provider.CreateQuery(expression));
}
