| |
| |
| Component @org.apache.wicket.markup.repeater.RefreshingView@ is a subclass of RepeatingView that comes with a customizable rendering strategy for its children components. |
| |
| RefreshingView defines abstract methods populateItem(Item) and getItemModels(). The first method is similar to the namesake method seen for ListView, but it takes in input an instance of class @org.apache.wicket.markup.repeater.Item@ which is a subclass of @ListItem@. RefreshingView is designed to display a collection of models containing the actual items. An iterator over these models is returned by the other abstract method getItemModels. |
| |
| The following code is a version of the previous example that uses @RefreshingView@ in place of @ListView@: |
| |
| *HTML:* |
| {code:html} |
| ... |
| <body> |
| <div id="bd" style="display: table;"> |
| <div wicket:id="persons" style="display: table-row;"> |
| <div style="display: table-cell;"><b>Full name: </b></div> |
| <div wicket:id="fullName" style="display: table-cell;"></div> |
| </div> |
| </div> |
| </body> |
| ... |
| {code} |
| |
| *Java Code (Page Constructor):* |
| {code} |
| public HomePage(final PageParameters parameters) { |
| //define the list of models to use |
| final List<IModel<Person>> persons = new ArrayList<IModel<Person>>(); |
| |
| persons.add(Model.of(new Person("John", "Smith"))); |
| persons.add(Model.of(new Person("Dan", "Wong"))); |
| |
| add(new RefreshingView<Person>("persons") { |
| @Override |
| protected void populateItem(Item<Person> item) { |
| item.add(new Label("fullName", new PropertyModel(item.getModel(), "fullName"))); |
| } |
| |
| @Override |
| protected Iterator<IModel<Person>> getItemModels() { |
| return persons.iterator(); |
| } |
| }); |
| } |
| {code} |
| |
| h3. Item reuse strategy |
| |
| Similar to @ListView@, the default behavior of the @RefreshingView@ is to replace its children with new instances every time is rendered. The strategy that decides if and how children components must be refreshed is returned by method @getItemReuseStrategy@. This strategy is an implementation of interface IItemReuseStrategy. The default implementation used by @RefreshingView@ is class @DefaultItemReuseStrategy@ but Wicket provides also strategy @ReuseIfModelsEqualStrategy@ which reuses an item if its model has been returned by the iterator obtained with method @getItemModels@. |
| |
| To set a custom strategy we must use method @setItemReuseStrategy@. |
