public static Expression Build(Expression memberAccess, string stringValue, ObjectFieldFilterOperator filterType)
{
if (string.IsNullOrEmpty(stringValue))
{
if (filterType == ObjectFieldFilterOperator.Equals)
{
return(Expression.Equal(memberAccess, Expression.Constant(null)));
}
if (filterType == ObjectFieldFilterOperator.DoesNotEqual)
{
return(Expression.NotEqual(memberAccess, Expression.Constant(null)));
}
throw new ArgumentOutOfRangeException(nameof(filterType), filterType, null);
}
DateTimeParseHelper.TryParse(stringValue, out var filterValue);
var date = Expression.Constant(filterValue, memberAccess.Type);
var nextDate = Expression.Constant(filterValue.AddDays(1), memberAccess.Type);
var prevDate = Expression.Constant(filterValue.AddDays(-1), memberAccess.Type);
Expression result;
switch (filterType)
{
case ObjectFieldFilterOperator.Equals:
result = Expression.AndAlso(Expression.LessThanOrEqual(date, memberAccess), Expression.LessThan(memberAccess, nextDate));
break;
case ObjectFieldFilterOperator.DoesNotEqual:
result = Expression.OrElse(Expression.LessThan(memberAccess, date), Expression.LessThanOrEqual(nextDate, memberAccess));
break;
case ObjectFieldFilterOperator.LessThan:
result = Expression.LessThan(memberAccess, date);
break;
case ObjectFieldFilterOperator.LessThanOrEquals:
result = Expression.LessThan(memberAccess, prevDate);
break;
case ObjectFieldFilterOperator.GreaterThan:
result = Expression.GreaterThanOrEqual(memberAccess, nextDate);
break;
case ObjectFieldFilterOperator.GreaterThanOrEquals:
result = Expression.GreaterThanOrEqual(memberAccess, date);
break;
default:
throw new ArgumentOutOfRangeException(nameof(filterType), filterType, null);
}
if (memberAccess.Type == typeof(DateTime?) && filterType == ObjectFieldFilterOperator.DoesNotEqual)
{
result = Expression.OrElse(result, Expression.Equal(memberAccess, Expression.Constant(null)));
}
return(result);
}
private static BinaryExpression CreateFilterExpression(Type propertyType, ObjectFieldFilterOperator @operator, Expression leftExpression, Expression rightExpression)
{
if (propertyType == typeof(string))
{
var compareToInvocation = Expression.Call(leftExpression, typeof(string).GetMethod("CompareTo", new[] { typeof(string) }), rightExpression);
return(makeBinaryExpressionByOperator[@operator](compareToInvocation, Expression.Constant(0, typeof(int))));
}
return(makeBinaryExpressionByOperator[@operator](leftExpression, rightExpression));
}
private static BinaryExpression CreateFilterExpression(ObjectFieldFilterOperator @operator, Expression leftExpression, Expression rightExpression)
{
return(makeBinaryExpressionByOperator[@operator](leftExpression, rightExpression));
}
