public static List <QueryableFilter> ToQueryableFilter(this List <string> strList)
{
List <QueryableFilter> retVal = new List <QueryableFilter>();
strList.ForEach(x =>
{
var indexOfFirstDelimiter = x.IndexOf("~");
string filterField = x.Substring(0, indexOfFirstDelimiter);
var indexOfSecondDelimiter = x.IndexOf("~", indexOfFirstDelimiter + 1);
string operandString = x.Substring(indexOfFirstDelimiter + 1, indexOfSecondDelimiter - indexOfFirstDelimiter - 1);
string filterValue = x.Substring(indexOfSecondDelimiter + 1, x.Length - indexOfSecondDelimiter - 1);
var op = (QueryableFilter.Operators)Enum.Parse(typeof(QueryableFilter.Operators), operandString, true);
var newQF = new QueryableFilter(filterField, op, filterValue);
retVal.Add(newQF);
});
return(retVal);
}
public static IQueryable <T> ApplyFilter <T>(this IQueryable <T> source, QueryableFilter filter)
{
var propertyInfoMatch = typeof(T).GetProperty(filter.Member, System.Reflection.BindingFlags.IgnoreCase | System.Reflection.BindingFlags.Instance | System.Reflection.BindingFlags.Public);
if (propertyInfoMatch == null)
{
throw new ArgumentException($"Unexpected filter field of {filter.Member} does not match a property on object {typeof(T).ToString()}");
}
bool isCollection = propertyInfoMatch.PropertyType != typeof(string) &&
typeof(IEnumerable).IsAssignableFrom(propertyInfoMatch.PropertyType);
string fullName = propertyInfoMatch.PropertyType.FullName;
bool isDateTime = fullName.Contains("System.DateTime"); // Contains handles nullable fields.
bool isGuid = fullName.Contains("System.Guid"); // Contains handles nullable fields.
bool isBoolean = fullName.Contains("System.Boolean"); // Contains handles nullable fields.
bool isShort = fullName.Contains("System.Int16");
bool isInt = fullName.Contains("System.Int32");
Func <string, string, string> condition;
if (isCollection)
{
condition = (format, member) => string.Format("{0}.Any({1})", member, string.Format(format, "it")); // System.Linq.Dynamic Collection: {PropertyName}.Any(it{condition})
}
else
{
condition = (format, member) => string.Format(format, member); // System.Linq.Dynamic Object: {PropertyName}{condition}
}
object typedFilterValue = filter.Value;
if (isDateTime)
{
typedFilterValue = DateTime.Parse(filter.Value);
}
else if (isGuid)
{
typedFilterValue = Guid.Parse(filter.Value);
}
else if (isBoolean)
{
typedFilterValue = Boolean.Parse(filter.Value);
}
else if (isShort)
{
typedFilterValue = Int16.Parse(filter.Value);
}
else if (isInt)
{
typedFilterValue = Int32.Parse(filter.Value);
}
switch (filter.Operator)
{
case QueryableFilter.Operators.IsGreaterThanOrEqual:
source = source.Where(condition("{0} >= (@0)", filter.Member), typedFilterValue);
break;
case QueryableFilter.Operators.IsLessThanOrEqual:
source = source.Where(condition("{0} <= (@0)", filter.Member), typedFilterValue);
break;
case QueryableFilter.Operators.IsGreaterThan:
source = source.Where(condition("{0} > (@0)", filter.Member), typedFilterValue);
break;
case QueryableFilter.Operators.IsLessThan:
source = source.Where(condition("{0} < (@0)", filter.Member), typedFilterValue);
break;
case QueryableFilter.Operators.Contains:
source = source.Where(condition("{0}.Contains(@0)", filter.Member), typedFilterValue);
break;
case QueryableFilter.Operators.DoesNotContain:
source = source.Where(condition("!{0}.Contains(@0)", filter.Member), typedFilterValue);
break;
case QueryableFilter.Operators.IsEqualTo:
source = source.Where(condition("{0} = @0", filter.Member), typedFilterValue);
break;
case QueryableFilter.Operators.IsNotEqualTo:
source = source.Where(condition("{0} != @0", filter.Member), typedFilterValue);
break;
case QueryableFilter.Operators.StartsWith:
source = source.Where(condition("{0}.StartsWith(@0)", filter.Member), typedFilterValue);
break;
case QueryableFilter.Operators.EndsWith:
source = source.Where(condition("{0}.EndsWith(@0)", filter.Member), typedFilterValue);
break;
case QueryableFilter.Operators.IsNull:
source = source.Where(condition("{0} = NULL", filter.Member));
break;
case QueryableFilter.Operators.IsNotNull:
source = source.Where(condition("{0} != NULL", filter.Member));
break;
case QueryableFilter.Operators.IsEmpty:
source = source.Where(condition("string.IsNullOrEmpty({0})", filter.Member));
break;
case QueryableFilter.Operators.IsNotEmpty:
source = source.Where(condition("!string.IsNullOrEmpty({0})", filter.Member));
break;
}
return(source);
}
