Package org.apache.tapestry5.corelib.components

Class PageLink

  • All Implemented Interfaces:
    ClientElement
    public class PageLink
extends AbstractLink
    Generates a render request link to some other page in the application. If an activation context is supplied (as the context parameter), then the context values will be encoded into the URL. If no context is supplied, then the target page itself will supply the context via a passivate event. Pages are not required to have an activation context. When a page does have an activation context, the value typically represents the identity of some object displayed or otherwise manipulated by the page.
    Component Parameters 
    NameTypeFlagsDefaultDefault Prefix
    anchorString  literal
    An anchor value to append to the generated URL (the hash separator will be added automatically).
    contextObject[]  prop
    If provided, this is the activation context for the target page (the information will be encoded into the URL). If not provided, then the target page will provide its own activation context.
    disabledboolean falseprop
    If true, then then no link element is rendered (and no informal parameters as well). The body is, however, still rendered.
    pageObjectRequired, Not Null literal
    The page to link to. If a String, as usual, it should be the page logical name. If it's a Class instance, it's treated as the target page. If it's not a String nor an Class, the target page will be the result of calling page.getClass(). Notice you'll need to use the prop binding when passing a value which isn't a String.
    parametersjava.util.MapNot Null, Since 5.3 prop
    If specified, the parameters are added to the link as query parameters in key=value fashion. Values will be coerced to string using value encoder; keys should be Strings.

    Related Components

    Examples

    We're continuing with the example introduced in the Grid examples.

    The UserList page renders a series of page links, passing the user id as the context:

    UserList.html (partial)

            <t:grid source="users" row="user" model="model">
            <p:lastnamecell>
                <t:pagelink page="user/view" context="user.id">${user.lastname}</t:pagelink>
            </p:lastnamecell>

        </t:grid>

    ViewUser.java

    The ViewUser page is responsible for converting that user id back into a User instance, by providing an event handler method for the "activate" event. 

    public class ViewUser
{
    private User user;

    @Inject
    private UserDAO userDAO;

    public User getUser()
    {
        return user;
    }

    void onActivate(long userId)
    {
        user = userDAO.findById(userId);
    }
}

    ViewUser.tml

    <html xmlns:t="http://tapestry.apache.org/schema/tapestry_5_0_0.xsd">
    <body>
        <h1>View User</h1>

        <t:beandisplay object="user"/>
    </body>
</html>

    Rendering out the User object, using a BeanDisplay component, is easy, and the template doesn't have to know or care about the page activation context; it just reads the user property.