Re-using code in controller class - asp.net-mvc-3

Question

The following code is taken from the tutorial: http://www.asp.net/mvc/tutorials/getting-started-with-aspnet-mvc3/cs/examining-the-edit-methods-and-edit-view which shows how ASP.net MVC 3 can be used to manage a movie database.
In the tutoral, a list object is added to the controller class that contains every movie genre that exists in the database. This list is then passed to a drop-down in the view enabling the database to be searched by genre.
Controller: (code related to movie genre in bold)
public ActionResult SearchIndex(string movieGenre, string searchString)
{
var GenreLst = new List<string>();
var GenreQry = from d in db.Movies
orderby d.Genre
select d.Genre;
GenreLst.AddRange(GenreQry.Distinct());
ViewBag.movieGenre = new SelectList(GenreLst);
var movies = from m in db.Movies
select m;
if (!String.IsNullOrEmpty(searchString))
{
movies = movies.Where(s => s.Title.Contains(searchString));
}
if (string.IsNullOrEmpty(movieGenre))
return View(movies);
else
{
return View(movies.Where(x => x.Genre == movieGenre));
}
}
What I want to do is enhance this further so that the movies can be searched by price as well as genre. I know I can re-use the much of the same code to do this. I think I need to create a new class that the controller class can pass either the genre or price. Is this correct? IF so, I'd appreciate an example. Thanks.
Update/Clarification:
I want to avoid repeating the code for both genre and price as below:
public ActionResult SearchIndex(string movieGenre, string searchString,float moviePrice)
{
var GenreLst = new List<string>();
var GenreQry = from d in db.Movies
orderby d.Genre
select d.Genre;
GenreLst.AddRange(GenreQry.Distinct());
ViewBag.movieGenre = new SelectList(GenreLst);
var PriceLst = new List<string>();
var PriceQry = from d in db.Movies
orderby d.Genre
select d.Genre;
PriceLst.AddRange(GenreQry.Distinct());
ViewBag.moviePrice = new SelectList(PriceLst);
var movies = from m in db.Movies
select m;
if (!String.IsNullOrEmpty(searchString))
{
movies = movies.Where(s => s.Title.Contains(searchString));
}
if (string.IsNullOrEmpty(movieGenre))
return View(movies);
else
{
return View(movies.Where(x => x.Genre == movieGenre));
}
if (string.IsNullOrEmpty(moviePrice))
return View(movies);
else
{
return View(movies.Where(x => x.Genre == moviePrice));
}
}

Answer 1

You just have to insert a text box in the view to get price value. Then receive this value at action and modify the query to get desired results.
like this:
#Html.ActionLink("Create New", "Create")
#using (Html.BeginForm()){
<p>Genre: #Html.DropDownList("movieGenre", "All")
Title: #Html.TextBox("SearchString")
Price: #Html.TextBox("Price")
<input type="submit" value="Filter" /></p>
}
And in the action method you are using the code below to populate the dropdownlist with genre values. You need not do the same for price value.
var GenreLst = new List<string>();
var GenreQry = from d in db.Movies
orderby d.Genre
select d.Genre;
GenreLst.AddRange(GenreQry.Distinct());
ViewBag.movieGenre = new SelectList(GenreLst);
And in your action method you just have to use the value of price to filter data
public ActionResult SearchIndex(string movieGenre, string searchString,float price)
{
var GenreLst = new List<string>();
var GenreQry = from d in db.Movies
orderby d.Genre
select d.Genre;
GenreLst.AddRange(GenreQry.Distinct());
ViewBag.movieGenre = new SelectList(GenreLst);
var movies = from m in db.Movies
select m;
if (!String.IsNullOrEmpty(searchString))
{
movies = movies.Where(s => s.Title.Contains(searchString));
}
if (string.IsNullOrEmpty(movieGenre))
return View(movies);
else
{
return View(movies.Where((x => x.Genre == movieGenre) &&(x => x.Price== price)));
}
}

Answer 2

You can do it in so many different ways while all are correct but it depends on the complexity of your project. Basically you don't want to over-engineer a simple program. But in general you should move all of your logic to a separate class and use your actions for creating and calling the right logic class:
public class GetMoviesRequest
{
public string Name { get; set; }
public float? Price { get; set; }
}
public class MoviesLogic
{
private List<Movie> Movies;
public IEnumerable<Movie> Get(GetMoviesRequest request)
{
IEnumerable<Movie> filtered = Movies.AsQueryable();
if (!string.IsNullOrEmpty(request.Name))
{
//Filter by name
filtered = filtered.Where(m => m.Name == request.Name);
}
if (request.Price.HasValue)
{
//Filter by value
filtered = filtered.Where(m => m.Price == request.Price);
}
return filtered;
}
}
public class MyController
{
public ActionResult SearchIndex(string movieGenre, string searchString)
{
var logic = new MoviesLogic();
var movies = logic.Get(new GetMoviesRequest() { Name = searchString } )
///do stuff with movies
}
}