asp.net mvc 3 webgrid sorting remains ?sortdir=ASC

Question

I\'m experimenting a bit with several grids in asp.net mvc. Microsoft has a grid too know in the prerelease of mvc 3 so I thought I\'ll try that one out.

The basic funct

Answer 1

This happens because grid column names must correspond to your fields or properties. Method which generates url in grid header compares "sort" from url query string with bounded columns and with grid column name. The three of them must be the same. If definition of your column name is not configured properly, the url will not be generated correctly.

Anyway .. here is some examples of properly defined column names.

Here we have sample domain class to display

public class Person
{
    public string FirstName;
    public string LastName;
    public Address LivesIn;
}

public class Address
{
    public string Country;
    public string City;
}

Now lets display List

Use your column names as fields

grid.Column("FirstName"),
grid.Column("LastName"),
grid.Column("LivesIn.City"),
grid.Column("LivesIn.Country")

... all columns has correct sorting url

If you make a typo in column name you got exception

grid.Column("FirstName"),
grid.Column("MyLastName"), <-- this throws exception
grid.Column("LivesIn.City"),
grid.Column("LivesIn.Country")

But you can use format and there will be no exception thrown

grid.Column("FirstName"),
grid.Column("MyLastName", format: item => item.LastName),
grid.Column("LivesIn.City"),
grid.Column("LivesIn.Country")

... but sorting url for column MyLastName will be BAD !!! all the time sortDir=ASC

You need to use good column name to has proper sorting url and custom format so ...

grid.Column("FirstName"),
grid.Column("LastName", format: item => item.LastName),
grid.Column("LivesIn.City"),
grid.Column("LivesIn.Country")

... everything is ok

How about complex type ?

grid.Column("FirstName"),
grid.Column("LastName"),
grid.Column("LivesIn.MyNonExistingField", format: item => item.LivesIn.City),
grid.Column("LivesIn.Country")

.... wow ... everything is ok .. that's kid of bug .. column "LivesIn.MyNonExistingField" has proper sorting url.

Ok ... What if we don't want to expose our domain structure. Then we need to add list of column names during binding

var grid = new WebGrid(persons, columnNames: new [] { "Foo" });
-- or --
grid.Bind(persons, columnNames: new [] { "Foo" });

grid.Column("Foo", format: item => item.FirstName),
grid.Column("LastName"),
grid.Column("LivesIn.MyNonExistingField", format: item => item.LivesIn.City),
grid.Column("LivesIn.Country")

.. now Foo column has proper sorting url

But careful !!! There is another bug.

If we add manual column names to binding then all column will be skipped until manual column is found. Example :

var grid = new WebGrid(persons, columnNames: new [] { "Foo" });
-- or --
grid.Bind(persons, columnNames: new [] { "Foo" });

grid.Column("FirstName"),
grid.Column("Foo", format: item => item.LastName),
grid.Column("LivesIn.MyNonExistingField", format: item => item.LivesIn.City),
grid.Column("LivesIn.Country")

... sorting url for column "FirstName" will not be generated correctly ... sortDir=ASC all the time ...to fix this add also a "FirstName" as column name like this:

var grid = new WebGrid(persons, columnNames: new [] { "FirstName", "Foo" });
-- or --
grid.Bind(persons, columnNames: new [] { "FirstName", "Foo" });

grid.Column("FirstName"),
grid.Column("Foo", format: item => item.LastName),
grid.Column("LivesIn.MyNonExistingField", format: item => item.LivesIn.City),
grid.Column("LivesIn.Country")

@Kohen

Remove columnNames in your code here

var grid = new System.Web.Helpers.WebGrid(Model.SubscriptionList,  
          columnNames: new List(){"Title"},  
          canPage:false);

... or add there all your column names like "ID", "ISP", etc