Searching Using Expression Trees

[Sam-I-Am]

I have added the following method to my instance of RepositoryBase:
public IQueryable<TEntity> Search(IList<Expression<Func<TEntity,
bool>>> criteria)
{
var query = RepositoryQuery;
foreach (var criterion in criteria)
{
query = query.Where(criterion);
}
return query.AsQueryable();
}

This lets me build up expressions to be passed in for searching:
[Test]
public void Can_Use_QueryHandler()
{
QueryHandler<Event> queryHandler = new
QueryHandler<Event>();
queryHandler.AddCriteria(x =>
x.Venue.Address.Region.Name.Equals("Western Cape"));
queryHandler.AddCriteria(x => x.Name.Contains("Test"));
queryHandler.AddCriteria(x => x.EventStatus ==
EventStatus.Live);

IList<Event> results;
using (UnitOfWorkScope scope = new UnitOfWorkScope())
{
results =
_eventRepository.Search(queryHandler.Criteria).ToList();
}

}

public class QueryHandler<T> where T : IEntity
{
private IList<Expression<Func<T, bool>>> _criteria;

public QueryHandler(){

_criteria = new List<Expression<Func<T, bool>>>();
}

/// <summary>
///
/// </summary>
/// <param name="func">A lambda function to apply</param>
public void AddCriteria(Expression<Func<T, bool>> func)
{
_criteria.Add(func);
}

public IList<Expression<Func<T, bool>>> Criteria
{
get
{
return _criteria;
}
}
}

[Ritesh Rao]

I'm not sure how this is any more useful than specifying predicates as
linq expressions using where? If the intent is to re-use predicates, I
would classify those as specifications, and you can specify
specifications using the Specification base class (you can even
combine multiple specifications which effectively do the exact same
thing as below).