Page Templates - ASP.NET Dynamic Data - page 183

</div>
</ItemTemplate>
</asp:FormView>
Notice how the DynamicHyperLink controls in this example do not have the
ContextTypeName and TableName properties specified. The FormView control databinds its
ItemTemplate to the entity instance provided by the associated EntityDataSource control.
The controls locate the MetaTable object based on the entity type and generate URLs that
look like this:
http://localhost/Products/Edit.aspx?ProductID=1
http://localhost/Products/Delete.aspx?ProductID=1
http://localhost/Products/List.aspx?ProductID=1
Dynamic hyperlinks can be also generated with the help of the RouteUrl markup expres-
sion. This is a special syntax that ASP.NET parser recognizes and uses to generate a
dynamic URL based on parameter values you specify:
<asp:HyperLink runat=”server” Text=”Show all”
NavigateUrl=” <%$RouteUrl:table=Products, action=List%> ” />
Under the hood, both the RouteUrl markup expression and the DynamicHyperLink control
rely on the low-level API the ASP.NET provides for routing. The next code sample illus-
trates how they work by creating a dynamic hyperlink programmatically. It creates a
RouteValueDictionary to hold the Table and Action parameter values and then calls the
GetVirtualPath method of the global Routes collection to generate the URL in a form of a
virtual path:
HyperLink hyperLink = // ...
RequestContext context =
DynamicDataRouteHandler.GetRequestContext(HttpContext.Current);
RouteValueDictionary routeValues = new RouteValueDictionary();
routeValues[“table”] = “Products”;
routeValues[“action”] = “List”;
VirtualPathData pathData = RouteTable.Routes.GetVirtualPath(
context, routeValues);
hyperLink.NavigateUrl = pathData.VirtualPath;
Route Evaluation and Constraints
Although you will probably never need to write code that creates dynamic hyperlinks
programmatically, it is important to understand how they are generated by the ASP.NET