internal SingleFilterInfo ParseFilter(string filterPart)
{
filterPart = filterPart.Replace("==", "=");
var filterInfo = new SingleFilterInfo
{
OperatorValue = DetermineFilterOperator(filterPart)
};
var filterStringParts = filterPart.Split((char)filterInfo.OperatorValue);
filterInfo.PropName =
filterStringParts[0].Replace("[", "").
Replace("]", "").Replace(" AND ", "").Trim();
// Get the property descriptor for the filter property name.
var filterPropDesc = TypeDescriptor.GetProperties(typeof(T))[filterInfo.PropName];
// Convert the filter compare value to the property type.
if (filterPropDesc == null)
{
throw new InvalidOperationException("Specified property to " +
"filter " + filterInfo.PropName +
" on does not exist on type: " + typeof(T).Name);
}
filterInfo.PropDesc = filterPropDesc;
var comparePartNoQuotes = StripOffQuotes(filterStringParts[1]);
try
{
var converter = TypeDescriptor.GetConverter(filterPropDesc.PropertyType);
filterInfo.CompareValue =
converter.ConvertFromString(comparePartNoQuotes);
}
catch (NotSupportedException)
{
throw new InvalidOperationException("Specified filter" +
"value " + comparePartNoQuotes + " can not be converted" +
"from string. Implement a type converter for " +
filterPropDesc.PropertyType);
}
return(filterInfo);
}
internal void ApplyFilter(SingleFilterInfo filterParts, bool addMatches = true)
{
// Check to see if the property type we are filtering by implements
// the IComparable interface.
var interfaceType =
TypeDescriptor.GetProperties(typeof(T))[filterParts.PropName]
.PropertyType.GetInterface("IComparable");
if (interfaceType == null)
{
throw new InvalidOperationException(
"Filtered property must implement IComparable.");
}
var removes = new List <T>();
// Check each value and add to the results list.
if (addMatches)
{
foreach (var item in originalList.Where(i => !Contains(i)))
{
if (filterParts.PropDesc.GetValue(item) == null || Contains(item))
{
continue;
}
var compareValue = filterParts.PropDesc.GetValue(item) as IComparable;
var result = compareValue.CompareTo(filterParts.CompareValue);
if (filterParts.OperatorValue == EQ && result == 0)
{
Add(item);
}
if (filterParts.OperatorValue == GT && result > 0)
{
Add(item);
}
if (filterParts.OperatorValue == LT && result < 0)
{
Add(item);
}
}
}
else // removing items that don't match
{
foreach (var item in this)
{
if (filterParts.PropDesc.GetValue(item) == null || !Contains(item))
{
continue;
}
var compareValue = filterParts.PropDesc.GetValue(item) as IComparable;
var result = compareValue.CompareTo(filterParts.CompareValue);
if (filterParts.OperatorValue == EQ && result != 0)
{
removes.Add(item);
}
if (filterParts.OperatorValue == GT && result <= 0)
{
removes.Add(item);
}
if (filterParts.OperatorValue == LT && result >= 0)
{
removes.Add(item);
}
}
}
foreach (var item in removes)
{
Remove(item);
}
}
