Friendly URLs for ASP.NET

Question

Python frameworks always provide ways to handle urls that convey the data of the request in an elegant way:

think

http://somewhere.overtherainbow.com/userid/123424/

I want your to notice the ending path /userid/123424/

How do you do this in ASP.NET?

Answer 1

There are a lot of ways to accomplish this. ScottGu has a good overview in this blog post.

Answer 2

You can read Rob Connerys post ASP.NET MVC: Using RESTful Architecture

http://blog.wekeroad.com/2007/12/06/aspnet-mvc-using-restful-architecture/

Also read this post on rewriting URLs using an IHttpHandler:

http://codeeleven.blogspot.com/2007/11/rewriting-urls-in-aspnet-without-using.html

Answer 3

Also, check out ASP.NET MVC or if you're set on webforms, the new System.Web.Routing namespace in ASP.NET 3.5 SP1

Answer 4

This example uses ASP.NET Routing to implement friendly URLs.

Examples of the mappings that the application handles are:

http://samplesite/userid/1234 - http://samplesite/users.aspx?userid=1234
http://samplesite/userid/1235 - http://samplesite/users.aspx?userid=1235

This example uses querystrings and avoids any requirement to modify the code on the aspx page.

Step 1 - add the necessary entries to web.config

<system.web>
<compilation debug="true">
     <assemblies>
      …
      <add assembly="System.Web.Routing, Version=3.5.0.0,    Culture=neutral, PublicKeyToken=31BF3856AD364E35"/>
     </assemblies>
    </compilation>
…
    <httpModules>
    …
        <add name="UrlRoutingModule" type="System.Web.Routing.UrlRoutingModule, System.Web.Routing, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" />
        </httpModules>
</system.web>
<system.webServer>
    …
    <modules>
     …
     <add name="UrlRoutingModule" type="System.Web.Routing.UrlRoutingModule, System.Web.Routing, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"/>
    </modules>
    <handlers
…   
     <add name="UrlRoutingHandler" preCondition="integratedMode" verb="*" path="UrlRouting.axd" type="System.Web.HttpForbiddenHandler,                 System.Web, Version=2.0.0.0, Culture=neutral,              PublicKeyToken=b03f5f7f11d50a3a"/>
    </handlers>
</system.webServer>

Step 2 - add a routing table in global.asax

Define the mapping from the friendly URL to the aspx page, saving the requested userid for later use.

void Application_Start(object sender, EventArgs e)
{
    RegisterRoutes(RouteTable.Routes);
}

public static void RegisterRoutes(RouteCollection routes)
{
    routes.Add("UseridRoute", new Route
    (
       "userid/{userid}",
       new CustomRouteHandler("~/users.aspx")
    ));
}

Step 3 - implement the route handler

Add the querystring to the current context before the routing takes place.

using System.Web.Compilation;
using System.Web.UI;
using System.Web;
using System.Web.Routing;

public class CustomRouteHandler : IRouteHandler
{
    public CustomRouteHandler(string virtualPath)
    {
        this.VirtualPath = virtualPath;
    }

    public string VirtualPath { get; private set; }

    public IHttpHandler GetHttpHandler(RequestContext
          requestContext)
    {
        // Add the querystring to the URL in the current context
        string queryString = "?userid=" + requestContext.RouteData.Values["userid"];
        HttpContext.Current.RewritePath(
          string.Concat(
          VirtualPath,
          queryString)); 

        var page = BuildManager.CreateInstanceFromVirtualPath
             (VirtualPath, typeof(Page)) as IHttpHandler;
        return page;
    }
}

Code from users.aspx

The code on the aspx page for reference.

protected void Page_Load(object sender, EventArgs e)
{
    string id = Page.Request.QueryString["userid"];
    switch (id)
    {
        case "1234":
            lblUserId.Text = id;
            lblUserName.Text = "Bill";
            break;
        case "1235":
            lblUserId.Text = id;
            lblUserName.Text = "Claire";
            break;
        case "1236":
            lblUserId.Text = id;
            lblUserName.Text = "David";
            break;
        default:
            lblUserId.Text = "0000";
            lblUserName.Text = "Unknown";
            break;
}

Answer 5

This is an alternative example that also uses ASP.NET Routing to implement friendly URLs.

Examples of the mappings that the application handles are:

http://samplesite/userid/1234 - http://samplesite/users.aspx?userid=1234
http://samplesite/userid/1235 - http://samplesite/users.aspx?userid=1235

This example does not use querystrings but requires additional code on the aspx page.

Step 1 - add the necessary entries to web.config

<system.web>
<compilation debug="true">
     <assemblies>
      …
      <add assembly="System.Web.Routing, Version=3.5.0.0,    Culture=neutral, PublicKeyToken=31BF3856AD364E35"/>
     </assemblies>
    </compilation>
…
    <httpModules>
    …
        <add name="UrlRoutingModule" type="System.Web.Routing.UrlRoutingModule, System.Web.Routing, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" />
        </httpModules>
</system.web>
<system.webServer>
    …
    <modules>
     …
     <add name="UrlRoutingModule" type="System.Web.Routing.UrlRoutingModule, System.Web.Routing, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"/>
    </modules>
    <handlers
…   
     <add name="UrlRoutingHandler" preCondition="integratedMode" verb="*" path="UrlRouting.axd" type="System.Web.HttpForbiddenHandler,                 System.Web, Version=2.0.0.0, Culture=neutral,              PublicKeyToken=b03f5f7f11d50a3a"/>
    </handlers>
</system.webServer>

Step 2 - add a routing table in global.asax

Define the mapping from the friendly URL to the aspx page, saving the requested userid for later use.

void Application_Start(object sender, EventArgs e)
{
    RegisterRoutes(RouteTable.Routes);
}

public static void RegisterRoutes(RouteCollection routes)
{
    routes.Add("UseridRoute", new Route
    (
       "userid/{userid}",
       new CustomRouteHandler("~/users.aspx")
    ));
}

Step 3 - implement the route handler

Pass the routing context, containing the parameter, to the page. (Note the definition of IRoutablePage)

using System.Web.Compilation;
using System.Web.UI;
using System.Web;
using System.Web.Routing;

public interface IRoutablePage
{
    RequestContext RequestContext { set; }
}

public class CustomRouteHandler : IRouteHandler
{
    public CustomRouteHandler(string virtualPath)
    {
        this.VirtualPath = virtualPath;
    }

    public string VirtualPath { get; private set; }

    public IHttpHandler GetHttpHandler(RequestContext
          requestContext)
    {
        var page = BuildManager.CreateInstanceFromVirtualPath
             (VirtualPath, typeof(Page)) as IHttpHandler;

        if (page != null)
        {
            var routablePage = page as IRoutablePage;

            if (routablePage != null) routablePage.RequestContext = requestContext;
        }

        return page;
    }
}

Step 4 - Retrieve the parameter on the target page

Note the implemetation of IRoutablePage.

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.Routing;

public partial class users : System.Web.UI.Page, IRoutablePage
{
    protected RequestContext requestContext;

    protected object RouteValue(string key)
    {
        return requestContext.RouteData.Values[key];
    }

    protected void Page_Load(object sender, EventArgs e)
    {
        string id = RouteValue("userid").ToString();
        switch (id)
        {
            case "1234":
                lblUserId.Text = id;
                lblUserName.Text = "Bill";
                break;
            case "1235":
                lblUserId.Text = id;
                lblUserName.Text = "Claire";
                break;
            case "1236":
                lblUserId.Text = id;
                lblUserName.Text = "David";
                break;
            default:
                lblUserId.Text = "0000";
                lblUserName.Text = "Unknown";
                break;
        }
    }

    #region IRoutablePage Members

    public RequestContext RequestContext
    {
        set { requestContext = value; }
    }

    #endregion
}

Answer 6

Here's another way of doing it using ASP.NET MVC

First off, here's the controller code with two actions. Index gets a list of users from the model, userid gets an individual user:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.Mvc;
using System.Web.Mvc.Ajax;

namespace MvcApplication1.Controllers
{
    public class UsersController : Controller
    {
        public ActionResult Index()
        {
            return View(Models.UserDB.GetUsers());
        }
        public ActionResult userid(int id)
        {
            return View(Models.UserDB.GetUser(id));
        }
    }
}

Here's the Index.asp view, it uses an ActionLink to create links in the correct format:

<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="Index.aspx.cs" Inherits="MvcApplication1.Views.Index" %>
<%@ Import Namespace="MvcApplication1.Controllers" %>
<%@ Import Namespace="MvcApplication1.Models" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"&gt;

<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
    <title></title>
</head>
<body>
    <div>
    <h2>Index of Users</h2>
           <ul>
            <% foreach (User user in (IEnumerable)ViewData.Model) { %>
                 <li>
                       <%= Html.ActionLink(user.name, "userid", new {id = user.id })%>
                 </li>
            <% } %>
           </ul>
    </div>
</body>
</html>

And here's the userid.aspx view which displays an individual's details:

<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="userid.aspx.cs" Inherits="MvcApplication1.Views.Users.userid" %>
<%@ Import Namespace="MvcApplication1.Controllers" %>
<%@ Import Namespace="MvcApplication1.Models" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"&gt;
<html xmlns="http://www.w3.org/1999/xhtml"&gt;
<head runat="server">
    <title></title>
</head>
<body>
    <div>
        <table border ="1">
            <tr>
                <td>
                ID
                </td>
                <td>
                <%=((User)ViewData.Model).id %>
                </td>
            </tr>
            <tr>
                <td>
                Name
                </td>
                <td>
                <%=((User)ViewData.Model).name %>
                </td>
            </tr>
        </table>
    </div>
</body>
</html>

And finally for completeness, here's the model code:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;

namespace MvcApplication1.Models
{
    public class UserDB
    {
        private static List<User> users = new List<User>{
            new User(){id=12345, name="Bill"},
            new User(){id=12346, name="Claire"},
            new User(){id=12347, name="David"}
        };

        public static List<User> GetUsers()
        {
            return users;
        }

        public static User GetUser(int id)
        {
            return users.First(user => user.id == id);
        }

    }

    public class User
    {
        public int id { get; set; }
        public string name { get; set; }
    }
}

Answer 7

thats for .net 3.5 . what about 2.0 ?

Answer 8

Use IIS7's URL Rewrite Module if you have the option available. http://www.iis.net/extensions/URLRewrite

Answer 9

I've been using a URL rewriter by Intelligencia:

http://urlrewriter.net/

It was so easy to configure - maybe an hour to get it all up and running. Very few problems with it...

I'd recommend it, but I should mentioned I've not tried any other ones.

Good luck!