/// <summary>
/// Gets the Linq.Expression that will represent the AdvancedPaging query
/// </summary>
/// <param name="model">The AdvancedPageModel</param>
/// <param name="genericType">The ParameterExpression that represents the Entity</param>
/// <returns>The Expression for the AdvancedPage</returns>
public Expression GetAdvancedSearchRestrictions(AdvancedPageModel model, ParameterExpression genericType)
{
Expression restrictions = null;
if (model.AdvancedSearch == null)
{
return(restrictions);
}
foreach (var adv in model.AdvancedSearch)
{
var valueA = (object)(adv.IntValue.HasValue ? adv.IntValue.Value : adv.Value);
var key = typeof(TEntity).GetPropertyExpressionFromSubProperty(adv.PropertyName, genericType);
//if (key.Type == typeof(int))
//{
// key = ((MemberExpression)key).ConvertToType(TypeCode.String);
//};
var propertyType = typeof(TEntity).FollowPropertyPath(adv.PropertyName).PropertyType;
var value = valueA != null?Expression.Constant(LambdaHelpers.ChangeType(valueA, propertyType)) : null;
Expression addedExpression = null;
switch (adv.TypeOfSearch)
{
case AdvancedSearchType.IsNull:
addedExpression = LambdaHelpers.NullableEqual(key, Expression.Constant(null));
break;
case AdvancedSearchType.IsNotNull:
addedExpression = LambdaHelpers.NullableNotEqual(key, Expression.Constant(null));
break;
case AdvancedSearchType.In:
addedExpression = LambdaHelpers.InExpression <TEntity>(genericType, adv.PropertyName, adv.ListValue);
break;
case AdvancedSearchType.Equal:
addedExpression = LambdaHelpers.NullableEqual(key, value);
break;
case AdvancedSearchType.NotEqual:
addedExpression = LambdaHelpers.NullableNotEqual(key, value);
break;
case AdvancedSearchType.LessThan:
addedExpression = LambdaHelpers.NullableLessThan(key, value);
break;
case AdvancedSearchType.LessThanEqual:
addedExpression = LambdaHelpers.NullableLessThanOrEqualTo(key, value);
break;
case AdvancedSearchType.GreaterThan:
addedExpression = LambdaHelpers.NullableGreaterThan(key, value);
break;
case AdvancedSearchType.GreaterThanEqual:
addedExpression = LambdaHelpers.NullableGreaterThanOrEqualTo(key, value);
break;
case AdvancedSearchType.Between:
var lowerBound = Expression.GreaterThanOrEqual(key, Expression.Constant(Convert.ChangeType(adv.Value, propertyType)));
var upperBound = Expression.LessThanOrEqual(key, Expression.Constant(Convert.ChangeType(adv.Value2, propertyType)));
addedExpression = Expression.AndAlso(lowerBound, upperBound);
break;
case AdvancedSearchType.Like:
default:
var method = typeof(string).GetMethod("Contains", new[] { typeof(string) });
var someValue = Expression.Constant(valueA, typeof(string));
addedExpression = Expression.Call(key, method, someValue);
break;
}
//add the new expression to the list
restrictions = restrictions == null
? addedExpression
: Expression.AndAlso(restrictions, addedExpression);
}
return(restrictions);
}