private static Expression GetSearchExpressionForProp(ParameterExpression param, Expression x, string search)
{
ReplaceParameter visitor = new ReplaceParameter();
var pExpression = (x.NodeType == ExpressionType.Convert) ? visitor.Modify((x as UnaryExpression).Operand, param) : visitor.Modify(x, param);
Type propType = pExpression.Type;
if (propType.BaseType == typeof(Enum))
{
var searchExpression = Expression.Constant(search.Trim().ToLower());
var toStringExpression = Expression.Call(pExpression, typeof(Enum).GetMethods().First(m => m.Name == "ToString"));
var toLowerExpression = Expression.Call(toStringExpression, typeof(string).GetMethods().First(m => m.Name == "ToLower"));
var pNotNullExpression = Expression.Constant(true);//Expression.NotEqual(pExpression, Expression.Constant(null));
var pContainsExpression = Expression.Call(toLowerExpression, typeof(string).GetMethod("Contains"), searchExpression);
return(Expression.AndAlso(pContainsExpression, pNotNullExpression));
}
if (propType == typeof(DateTime) || propType == typeof(DateTime?))
{
return(BuildDateTimeExpression(x, param, search));
}
if (propType == typeof(string))
{
var searchExpression = Expression.Constant(search.Trim().ToLower());
var toLowerExpression = Expression.Call(pExpression, typeof(string).GetMethods().First(m => m.Name == "ToLower"));
var pNotNullExpression = Expression.NotEqual(pExpression, Expression.Constant(null));
var pContainsExpression = Expression.Call(toLowerExpression, typeof(string).GetMethod("Contains"), searchExpression);
return(Expression.IsTrue(pContainsExpression));
}
else
{
try
{
object converted = null;
if (Nullable.GetUnderlyingType(propType) != null)
{
converted = Convert.ChangeType(search.ToLower(), Nullable.GetUnderlyingType(propType));
return(Expression.AndAlso(Expression.NotEqual(pExpression, Expression.Constant(null)), Expression.Equal(Expression.Property(pExpression, "Value"), Expression.Constant(converted))));
}
else
{
converted = Convert.ChangeType(search.ToLower(), propType);
return(Expression.Equal(pExpression, Expression.Constant(converted)));
}
}
catch { return(Expression.Constant(false)); }
}
}
private static IQueryable <T> ApplyDataTablesSortImp <T>(this IQueryable <T> source, NameValueCollection request, int?count = 0)
{
request = GetRequest(request); if (request == null)
{
return(source);
}
string key = RequestKey <T>(request);
Expression <Func <T, object> >[] orderbys = null;
try
{
orderbys = (Expression <Func <T, object> >[])RequestDTOrderBys[key];
}
catch {
try
{
orderbys = (Expression <Func <T, object> >[])RequestDTSelects[key];
}
catch { }
}
PropertyInfo[] _properties = typeof(T).GetProperties();
// enumerate the keys for any sortations
foreach (string iSortKey in request.AllKeys.Where(x => x.StartsWith(DataTablesConst.INDIVIDUAL_SORT_KEY_PREFIX)))
{
// column number to sort (same as the array)
int sortcolumn = int.Parse(request[iSortKey]);
// ignore malformatted values
if (sortcolumn < 0 || sortcolumn >= _properties.Length)
{
continue;
}
// get the direction of the sort
string sortdir = request[DataTablesConst.INDIVIDUAL_SORT_DIRECTION_KEY_PREFIX + iSortKey.Replace(DataTablesConst.INDIVIDUAL_SORT_KEY_PREFIX, string.Empty)];
var param = Expression.Parameter(typeof(T), "val");
Expression pExpression;
if (orderbys != null && orderbys.Count() > sortcolumn)
{
Expression x = orderbys[sortcolumn].Body;
ReplaceParameter visitor = new ReplaceParameter();
pExpression = (x.NodeType == ExpressionType.Convert) ? visitor.Modify((x as UnaryExpression).Operand, param) : visitor.Modify(x, param);
}
else
{
pExpression = Expression.MakeMemberAccess(param, _properties[sortcolumn]);
}
Type propType = pExpression.Type;
var orderByExp = Expression.Lambda(pExpression, param);
MethodCallExpression resultExp;
if (string.IsNullOrEmpty(sortdir) || sortdir.Equals(DataTablesConst.ASCENDING_SORT, StringComparison.OrdinalIgnoreCase))
{
resultExp = Expression.Call(typeof(Queryable), "OrderBy", new Type[] { typeof(T), propType }, source.Expression, Expression.Quote(orderByExp));
}
else
{
resultExp = Expression.Call(typeof(Queryable), "OrderByDescending", new Type[] { typeof(T), propType }, source.Expression, Expression.Quote(orderByExp));
}
source = source.Provider.CreateQuery <T>(resultExp);
}
return(source);
}
private static Expression BuildDateTimeExpression(Expression x, ParameterExpression param, string search)
{
ReplaceParameter visitor = new ReplaceParameter();
var pExpression = (x.NodeType == ExpressionType.Convert) ? visitor.Modify((x as UnaryExpression).Operand, param) : visitor.Modify(x, param);
Type propType = pExpression.Type;
try
{
DateTime converted;
bool bDateTime = DateTime.TryParse(search, out converted);
if (bDateTime)
{
if (propType == typeof(DateTime?))
{
Expression notNull = Expression.NotEqual(pExpression, Expression.Constant(null));
Expression equal = Expression.Equal(Expression.Property(pExpression, "Value"), Expression.Constant(converted));
MethodInfo miTruncateTime = typeof(DbFunctions).GetMethods().First(m => m.Name == "TruncateTime" && m.GetParameters().First().ParameterType == typeof(DateTime?));
Expression dateEqual = Expression.Equal(Expression.Call(null, miTruncateTime, pExpression), Expression.Convert(Expression.Constant(converted.Date), typeof(DateTime?)));
Expression exp;
exp = Expression.AndAlso(notNull, equal);
exp = Expression.Or(exp, Expression.AndAlso(notNull, dateEqual));
return(exp);
}
else
{
Expression equal = Expression.Equal(pExpression, Expression.Constant(converted));
MethodInfo miTruncateTime = typeof(DbFunctions).GetMethods().First(m => m.Name == "TruncateTime" && m.GetParameters().First().ParameterType == typeof(DateTime?));
Expression dateEqual = Expression.Equal(Expression.Call(null, miTruncateTime, Expression.Convert(pExpression, typeof(DateTime?))), Expression.Constant(converted.Date));
Expression exp;
exp = equal;
exp = Expression.Or(exp, dateEqual);
return(exp);
}
}
int datePart;
bool bDatePart = int.TryParse(search, out datePart);
if (bDatePart)
{
if (propType == typeof(DateTime?))
{
Expression notNull = Expression.NotEqual(pExpression, Expression.Constant(null));
Expression yearEqual = Expression.Equal(Expression.Property(Expression.Property(pExpression, "Value"), "Year"), Expression.Constant(datePart));
Expression monthEqual = Expression.Equal(Expression.Property(Expression.Property(pExpression, "Value"), "Month"), Expression.Constant(datePart));
Expression exp;
exp = Expression.AndAlso(notNull, yearEqual);
exp = Expression.Or(exp, Expression.AndAlso(notNull, monthEqual));
return(exp);
}
else
{
Expression yearEqual = Expression.Equal(Expression.Property(pExpression, "Year"), Expression.Constant(datePart));
Expression monthEqual = Expression.Equal(Expression.Property(pExpression, "Month"), Expression.Constant(datePart));
Expression exp;
exp = yearEqual;
exp = Expression.Or(exp, monthEqual);
return(exp);
}
}
int day = -1;
string[] days = Enum.GetNames(typeof(DayOfWeek));
for (int i = 0; i < days.Length; i++)
{
if (days[i].ToLower() == search.Trim().ToLower())
{
day = i + 1;
}
}
if (day > -1)
{
if (propType == typeof(DateTime?))
{
Expression notNull = Expression.NotEqual(pExpression, Expression.Constant(null));
MethodInfo miSqlDatePart = typeof(SqlFunctions).GetMethods().First(m => m.Name == "DatePart" && m.GetParameters()[1].ParameterType == typeof(DateTime?));
Expression dayEqual = Expression.Equal(Expression.Property(Expression.Call(null, miSqlDatePart, Expression.Constant("weekday"), pExpression), "Value"), Expression.Constant(day));
return(Expression.AndAlso(notNull, dayEqual));
}
else
{
MethodInfo miSqlDatePart = typeof(SqlFunctions).GetMethods().First(m => m.Name == "DatePart" && m.GetParameters()[1].ParameterType == typeof(DateTime?));
Expression dayEqual = Expression.Equal(Expression.Property(Expression.Call(null, miSqlDatePart, Expression.Constant("weekday"), Expression.Convert(pExpression, typeof(DateTime?))), "Value"), Expression.Constant(day));
return(dayEqual);
}
}
return(Expression.Constant(false));
}
catch { return(Expression.Constant(false)); }
}
