MVC Page to Accept Different Query Arguments - asp.net-mvc

Question

I have a results view that displays a list of items.
In some cases, I want to display items where one field matches the query argument. In other cases, I want to display items where another field matches the query argument. And so on.
How can I provide arguments to my controller/view so that it knows what kind of results to get? I could write multiple controllers, but then I get the error that "Type 'MyType' already defines a member called 'MyMethod' with the same parameter type."
Ideally, I could find a way to do this without creating additional routes. Is this possible?

Answer 1

From what I understand from your question you want to do the following:
Reutilize a view, so that you don't have to make one for each query.
Use the same method name on a controller so that you don't have a different url for each query.
You could add an extra parameter to your method so that you can perform a different query depending on the value of the extra parameter:
public class QueryController
{
private enum QueryType
{
TypeA = 0,
TypeB = 1,
TypeC = 2
}
[HttpGet]
public void ShowResults(QueryType type, string criteria)
{
/*
* Code here to make the query using the field you want,
* depending on the "type" parameter e.g.
*
* switch (type)
* {
* case TypeA:
* model = db.Items.Where(x => x.FieldA == criteria);
* break;
* case TypeB:
* model = db.Items.Where(x => x.FieldB == criteria);
* break;
* }
*/
return View(model);
}
}
Another thing, don't worry about the routes, the default route {controller}/{method}/{id} doesn't demand that you have to specify the URLs in that strict way. This is a valid URL for the previous example:
http://www.example.com/App/Query/ShowResults?type=1&criteria=foo
The default MVC binder will use the parameter names in the URL to bind their values to the parameters of your method.
I hope I didn't misunderstood your question.
Good luck!

Answer 2

With MVC, query string values map to parameter values (and Routes are used to create custom mappings).
There are special exceptions though. If a parameter is a FormCollection (which is basically just a Dictionary<string>), then all un-mapped query string values will be passed in.
So, you can create a single Action that takes in all parameters:
// GET: MyController/ViewList?name=aaa&field1=foo&field2=bar
public ActionResult ViewList(string name, FormCollection otherFields) {
foreach (var field in otherFields) {
switch (field.Key.ToLower()) {
case "field1":
// Filter field1 based on field.Value
case "field2":
// Filter field2 based on field.Value
...
}
}
...
}
Similarly, you could also have no parameters, and just use this.Request.QueryString to inspect the query string values. However, I prefer the FormCollection method because it makes it clear that I expect other parameters.