public override void GenerateFilterIl(System.Reflection.Emit.ILGenerator generator, Dictionary <string, string> filterValues, PropertyInfo property)
{
MethodInfo StringToLower = typeof(string).GetMethod("ToLower", new Type[] { });
MethodInfo StringStartsWith = typeof(String).GetMethod("StartsWith", new Type[] { typeof(string) });
MethodInfo StringContains = typeof(String).GetMethod("Contains", new Type[] { typeof(string) });
MethodInfo StringIsNullOrWhiteSpace = typeof(string).GetMethod("IsNullOrWhiteSpace", new Type[] { typeof(string) });
Label lblNextProperty = generator.DefineLabel();
Label lblNotNull = generator.DefineLabel();
string filterText = filterValues["filterText"];
string filterMode = filterValues["filterMode"];
// Do nothing for this property is the filterText is blank and the filterMode is "Starts With", "Doesn't Start With", "Contains", or " Doesn't Contain"
if (string.IsNullOrWhiteSpace(filterText) && new string[] { "Starts With", "Doesn't Start With", "Contains", "Doesn't Contain" }.Contains(filterMode))
{
return;
}
switch (filterMode)
{
case "Starts With":
case "Contains":
// Check that the property is not null. If it is null, return false; otherwise, continue.
generator.EmitGetPropertyValueFromArgument(property);
generator.Emit(OpCodes.Brtrue, lblNotNull);
generator.EmitReturnFalse();
generator.MarkLabel(lblNotNull);
// Load the property of the argument and make it lower-case.
generator.EmitGetPropertyValueFromArgument(property);
generator.Emit(OpCodes.Callvirt, StringToLower);
// Load the lower-cased search key and see if the lower-cased property starts with it.
generator.Emit(OpCodes.Ldstr, filterText.ToLower());
// We use either String.StartsWith or String.Contains according to what the user specified.
generator.Emit(OpCodes.Callvirt, filterMode == "Starts With" ? StringStartsWith : StringContains);
// If the search key doesn't match, then return false; otherwise, go on to the next property
generator.Emit(OpCodes.Brtrue, lblNextProperty);
generator.EmitReturnFalse();
break;
case "Doesn't Start With":
case "Doesn't Contain":
// Check that the property is not null. If it is null, then go on to the next property.
generator.EmitGetPropertyValueFromArgument(property);
generator.Emit(OpCodes.Brfalse, lblNextProperty);
// Load the property of the argument and make it lower-case.
generator.EmitGetPropertyValueFromArgument(property);
generator.Emit(OpCodes.Callvirt, StringToLower);
// Load the lower-cased search key and see if the lower-cased property starts with it.
generator.Emit(OpCodes.Ldstr, filterText.ToLower());
// We use either String.StartsWith or String.Contains according to what the user specified.
generator.Emit(OpCodes.Callvirt, filterMode == "Starts With" ? StringStartsWith : StringContains);
// Since we're doing the opposite of the "Starts With" and "Contains" cases, go to the next property
// if the search key doesn't match, and return false otherwise.
generator.Emit(OpCodes.Brfalse, lblNextProperty);
generator.EmitReturnFalse();
break;
case "Is Blank":
// Load the property of the argument and see if it's null or whitespace
generator.EmitGetPropertyValueFromArgument(property);
generator.Emit(OpCodes.Call, StringIsNullOrWhiteSpace);
// If we didn't get back true, then return false; otherwise, go on to the next property.
generator.Emit(OpCodes.Brtrue, lblNextProperty);
generator.EmitReturnFalse();
break;
case "Isn't Blank":
// Load the property of the argument and see if it's null or whitespace
generator.EmitGetPropertyValueFromArgument(property);
generator.Emit(OpCodes.Call, StringIsNullOrWhiteSpace);
// If we didn't get back false, then return false; otherwise, go on to the next property.
generator.Emit(OpCodes.Brfalse, lblNextProperty);
generator.EmitReturnFalse();
break;
}
generator.MarkLabel(lblNextProperty);
}
public override void GenerateFilterIl(System.Reflection.Emit.ILGenerator generator, Dictionary <string, string> filterValues, PropertyInfo property)
{
string minDateString = filterValues["minDate"];
string maxDateString = filterValues["maxDate"];
bool isNullable = property.PropertyType.Name == "Nullable`1";
Label lblNextProperty = generator.DefineLabel();
Label lblReturnFalse = generator.DefineLabel();
// First, get the value loaded, but if it is null, then return false unless both minDate and maxDate are blank.
if (isNullable)
{
// This block of code is so-far UNTESTED!!!
MethodInfo GetNullableHasValue = typeof(DateTime?).GetProperty("HasValue").GetGetMethod();
MethodInfo GetNullableValue = typeof(DateTime?).GetProperty("Value").GetGetMethod();
bool minAndMaxBothBlank = string.IsNullOrWhiteSpace(minDateString) && string.IsNullOrWhiteSpace(maxDateString);
Label whereToGoIfNull = minAndMaxBothBlank ? lblNextProperty : lblReturnFalse;
// If the property is null and both min and max date are blank, then go to the next property.
// If the property is null and either min or max date has a value, return false.
generator.EmitGetPropertyValueFromArgument(property);
generator.Emit(OpCodes.Stloc, nullableDateTimeStorage);
generator.Emit(OpCodes.Ldloca_S, nullableDateTimeStorage);
generator.Emit(OpCodes.Call, GetNullableHasValue);
generator.Emit(OpCodes.Brfalse_S, whereToGoIfNull);
// If we haven't jumped, then the datetime is not null, so just save it.
generator.Emit(OpCodes.Ldloca_S, nullableDateTimeStorage);
generator.Emit(OpCodes.Call, GetNullableValue);
generator.Emit(OpCodes.Stloc, dateTimeStorage);
}
else // not nullable
{
// The property is not nullable, so just save the value.
generator.EmitGetPropertyValueFromArgument(property);
generator.Emit(OpCodes.Stloc, dateTimeStorage);
}
// At this point, the record's datetime should be saved in memory.
MethodInfo DateTimeParse = typeof(DateTime).GetMethod("Parse", new Type[] { typeof(string) });
MethodInfo DateTimeLessThanOrEqual = typeof(DateTime).GetMethod("op_LessThanOrEqual");
MethodInfo DateTimeGreaterThanOrEqual = typeof(DateTime).GetMethod("op_GreaterThanOrEqual");
if (!string.IsNullOrWhiteSpace(minDateString))
{
generator.Emit(OpCodes.Ldstr, minDateString);
generator.Emit(OpCodes.Call, DateTimeParse); // Get the mindate DateTime.
generator.Emit(OpCodes.Ldloc, dateTimeStorage); // Get the record's DateTime from memory
generator.Emit(OpCodes.Call, DateTimeLessThanOrEqual);
generator.Emit(OpCodes.Brfalse, lblReturnFalse);
}
if (!string.IsNullOrWhiteSpace(maxDateString))
{
generator.Emit(OpCodes.Ldstr, maxDateString);
generator.Emit(OpCodes.Call, DateTimeParse); // Get the maxdate DateTime.
generator.Emit(OpCodes.Ldloc, dateTimeStorage); // Get the record's DateTime from memory
generator.Emit(OpCodes.Call, DateTimeGreaterThanOrEqual);
generator.Emit(OpCodes.Brfalse, lblReturnFalse);
}
generator.Emit(OpCodes.Br, lblNextProperty);
generator.MarkLabel(lblReturnFalse);
generator.EmitReturnFalse();
generator.MarkLabel(lblNextProperty);
}