TSEARCH CLASS CODE

name :: text, '' )) ), ( to_tsquery ( 'english', ' '' ' || 'wool' || ' '' ' ) ), ? ) ) AS rank FROM products WHERE ( ( ( to_tsvector ( 'english', coalesce ( products. manufacturer_name :: text, '' )) || to_tsvector ( 'english', coalesce ( products. description :: text, '' )) || to_tsvector ( 'english', coalesce ( products. id AS pg_search_id, ( ts_rank ( ( to_tsvector ( 'english', coalesce ( products. * FROM products INNER JOIN ( SELECT products. You can try running it yourself.SELECT products. That's it! This is the result of the query: UsersQuery = searchFieldMutator.Apply(searchModel, usersQuery) The following actually does all the work, it changes query inside the usersQuery variable to the one specified by all the search strategies: foreach (var searchFieldMutator in SearchFieldMutators) Now that we have defined the two types of the strategy, we can create a class that holds them both, and also does the (simulated) mutation: public class SearchFieldMutator But if this is confusing, you can remove the generics completely, and replace any TItem with UserListItem and any TSearch with UserSearchViewModel.

TSEARCH CLASS CODE

NOTE: I've defined both the item type and the search data as generic types (as TItem and TSearch, respectively) so this code is usable in multiple locations in your code. I've created a new delegate type for it, so its usage is clear: public delegate IQueryable QueryMutator(IQueryable items, TSearch search) So it's not really mutation, but it has the same effect. It is supposed to 'mutate' the query by applying a LINQ operator to it, but really just returns a new query with the added operator, and the caller of it should discard the old query and keep the new one. (it could also have been written as Func) This is the type of the delegate: Predicate If it return true, the strategy is applied.

The first part is a delegate (of type Predicate) that returns true or false based on the data in the UserSearchViewModel (or any other type, since it only defines a generic type TSearch).

A way to decide if to apply the strategy.

Each strategy (called SearchFieldMutator in this example) will hold two things: You could associate each condition with a strategy for changing the query. I've fixed it and added a more complete example. You can then refactor this further by moving these methods into a service class if you want to.Д®DIT: I apologize from my earlier sample that didn't quite compile. Return Convert.ToInt32(Math.Ceiling((decimal)filteredCount / (decimal)PageSize)) Private int GetTotalPages(UserListItem users) If (!String.IsNullOrWhiteSpace(search.Name)) users = users.Where(u => u.FirstName.Contains(search.Name) Private UserListItem FilterUsers(object users, UserSearchViewModel search) Private UserListItem SortUsers(object users, string sort) Private UserListItem GetUsers(UserSearchViewModel search, string sort) Users = users.Skip(PageSize * (page - 1)).Take(PageSize).ToList(), something like this is more readable than the original: public UsersController : Controller If you want to clean up the code, you can always refactor it. I know this is old, but thought it may be helpful for anyone reading this. Users = users.Skip(PageSize * (page - 1)).Take(PageSize)

Users = users.OrderByDescending(u => u.UsertypeSortingOrder) Users = users.OrderBy(u => u.UsertypeSortingOrder) Users = users.OrderByDescending(u => u.Email) Users = users.OrderByDescending(u => u.FirstName).ThenByDescending(u => u.LastName) Users = users.OrderBy(u => u.FirstName).ThenBy(u => u.LastName) Int totalPages = Convert.ToInt32(Math.Ceiling((decimal)filteredCount / (decimal)PageSize)) Calculate the number of pages based on the filtering If () users = users.Where(u => u.UsertypeId = ) If (!String.IsNullOrWhiteSpace(search.Email)) users = users.Where(u => u.Email.Contains(search.Email)) If (!String.IsNullOrWhiteSpace(search.Name)) users = users.Where(u => u.FirstName.Contains(search.Name) || u.LastName.Contains(search.Name)) Public ActionResult Index(int page = 1, string sort = '', UserSearchViewModel search) Instead of ugly code in a controller, I'd end up with ugly code in a service. Some of you might suggest putting that code into a service class and not in the controller, but that would just move the ugly code somewhere else. Is there a better way to do the filtering and sorting with Entity Framework? In that application I have a lot of paged lists. I'm developing an application using ASP.NET MVC 3 and Entity Framework 4.1.

Tsearch class