Routing overview

Every page in DotVVM needs to be registered in the route table. DotVVM doesn't allow visiting a page just by putting its path in the URL.

The routes are configured as part of the configuration in the DotvvmStartup class.

To separate the configuration options, the default project templates contain ConfigureControls, ConfigureRoutes and ConfigureResources methods, which are called from the Configure method. You can use any structure you like - the only requirement is that the Configure method performs all the configuration actions.

Register routes one by one

In simple web applications, you can register each route individually using the following code snippet:

config.RouteTable.Add("Page", "my/page/url", "Views/page.dothtml", new { });

• The first argument is the name of the route. You'll need it when you do redirects, or generate a hyperlink that navigates the user to this page (e. g. using the RouteLink control). This name is not displayed to the user, it is only a string which identifies the route in the application code.

• The second argument is the route URL. It can contain route parameters (e.g. "product-detail/{ProductId}") which you can retrieve in the viewmodel when the page is loaded. For the default page, you can use "" as the route URL.

• The third argument is the location of the .dothtml file which will be used to handle the request. Because the file doesn't have to be in the Views folder, you need to pass an application relative path including the Views folder name: Views/page.dothtml.

• The fourth argument (optional) specifies default values for route parameters. If the parameter value is not specified in the URL, the value from this object will be used. You can pass an anonymous object with property names that correspond with the route parameter names, or IDictionary<string, object>.

Route groups

If you have several similar routes, you can register them as a group:

config.RouteTable.AddGroup("Admin", "admin", "Views/Admin", table =>
{
    table.Add("Customers", "customers", "Customers.dothtml");
    table.Add("Customer", "customer/{id}", "Customer.dothtml");
});

The AddGroup method allows specify a common prefix for all the routes. The routes will be registered according to the following table:

As you can see, the route name, route URL, and dothtml file location are composed from the AddGroup method parameters and the parameters of the particular route. Notice that the _ character is added between the group name and route name. Route URL and file location are treated like paths and joined by /.

Other route types

If you need to register a route which should not be treated as .dothtml file, e.g. if you need a handler that serves files, generates RSS feeds or anything like that, you can declare a custom presenter and specify a method, that creates an instance of it, as the fifth parameter.

If you change the URLs in your app, you can use redirection routes to preserve the old URLs.

If you have a larger project, you may want to use conventions to auto-discover routes instead of registering them one by one.

Using RouteLink to create links between pages

To create hyperlinks to DotVVM pages, it is recommended to use the RouteLink controls:

<dot:RouteLink RouteName="ArticleDetail" 
               Param-Id="{value: CurrentArticleId}" 
               Param-Title="{value: CurrentArticleTitle}" />

The route parameters can be specified using properties starting with Param-. If the parameter is not specified, and the current page has a parameter with the same name, the value from the current page will be used.

If the current page doesn't have this parameter, the default value from the route will be used. If no default value for the parameter is not specified, an empty string will be substituted for this parameter.

Redirect to another route

If you want to redirect the user to another page from the viewmodel code, you can call Context.RedirectToRoute("routeName", new { Param1 = param... }).

See also

• Parameters
• Route redirection
• Auto-discover routes
• Custom presenter