private Expression GetConstantExpression(Expression member, IFilterStatement statement)
{
var value = statement.Value;
if (value == null)
{
return(null);
}
Expression constant = Expression.Constant(value);
if (value is string)
{
var trimConstantCall = Expression.Call(constant, helper.trimMethod);
constant = Expression.Call(trimConstantCall, helper.toLowerMethod);
}
else if (statement.ValueIsList())
{
var myList = ValueList(statement);
constant = Expression.Constant(statement.Operation == Operation.Between ? new ArrayList(myList).ToArray(statement.GetPropertyType()) : myList);
}
return(constant);
}
private Expression GetSafeExpression(Expression member, IFilterStatement statement)
{
var operation = statement.Operation;
var matchType = new OperationHelper().FetchMatchType(operation, statement.MatchType);
var constant = GetConstantExpression(member, statement);
if (operation != Operation.Between && statement.ValueIsList())
{
if (operation == Operation.EqualTo && matchType == MatchType.Any)
{
return(Expressions[Operation.Contains].Invoke(member, constant));
}
else if (operation == Operation.NotEqualTo && matchType == MatchType.All)
{
return(Expressions[Operation.DoesNotContain].Invoke(member, constant));
}
else
{
var runningExpression = null as Expression;
var myList = ValueList(statement);
var connector = matchType == MatchType.Any ? Connector.Or : Connector.And;
foreach (var item in myList)
{
Expression loopConstant = Expression.Constant(item);
var loopExpression = Expressions[operation].Invoke(member, loopConstant);
runningExpression = runningExpression == null ? loopExpression : CombineExpressions(runningExpression, loopExpression, connector);
}
return(runningExpression ?? Expression.Constant(true));
}
}
return(Expressions[operation].Invoke(member, constant));
}