| <document> |
| <body> |
| |
| <section name="Examples"> |
| |
| <p> |
| The Delegate component allows us to be very flexible in how and what gets rendered, and |
| in what order. In some cases, the object to be rendered may come from an entirely |
| different page. |
| </p> |
| |
| <p> |
| This example is simpler, and could easily be accomplished using an If component. We'll create |
| a page that can be used for viewing or editting an object. |
| </p> |
| |
| <subsection name="ViewAccount.tml"> |
| |
| <source><![CDATA[ |
| <html xmlns:t="http://tapestry.apache.org/schema/tapestry_5_0_0.xsd"> |
| <body> |
| <h1>View Account</h1> |
| |
| <t:delegate to="activeBlock"/> |
| |
| <t:block id="view"> |
| <t:beandisplay object="account"/> |
| |
| <p><t:actionlink t:id="edit">Edit this account</t:actionlink></p> |
| </t:block> |
| |
| <t:block id="edit"> |
| <t:beaneditform t:id="account"/> |
| </t:block> |
| </body> |
| </html>]]></source> |
| |
| <p> |
| So we end up with a display of the Account's properties, and a link to activate edit mode. |
| In edit mode, we use the other block and show a BeanEditForm. |
| </p> |
| |
| </subsection> |
| |
| <subsection name="ViewAccount.java"> |
| <source><![CDATA[ |
| public class ViewAccount |
| { |
| @Persist |
| private Account account; |
| |
| @Persist |
| private boolean editMode; |
| |
| @Inject |
| private Block edit, view; |
| |
| @Inject |
| private AccountDAO accountDAO; |
| |
| public Account getAccount() |
| { |
| return account; |
| } |
| |
| public void setAccount(Account account) |
| { |
| account = account; |
| editMode = false; |
| } |
| |
| void onSuccess() |
| { |
| accountDAO.update(_account); |
| |
| editMode = false; |
| } |
| |
| void onActionFromEdit() |
| { |
| editMode = true; |
| } |
| |
| public Object getActiveBlock() |
| { |
| return editMode ? edit : view; |
| } |
| }]]></source> |
| |
| <p> |
| The use of the @Inject annotation on a field of type Block is used to access a |
| <code><![CDATA[<t:block>]]></code> |
| element from the template. The field name, |
| stripped of leading underscores, is matched against the block's id. |
| </p> |
| |
| <p> |
| The rest is concerned with handling the form submission, turning on edit mode, |
| and determining which block will be the one to render. |
| </p> |
| |
| |
| </subsection> |
| |
| </section> |
| |
| </body> |
| </document> |
