Cascader

CE
PE
EE

since 9.0

Employment/Purpose

Cascader is used to select an item from a hierarchical structure of data. It accepts a TreeModel.

Example

    <zscript><![CDATA[
    DefaultTreeModel treeModel = new DefaultTreeModel(new DefaultTreeNode("ROOT",
            Arrays.asList(new DefaultTreeNode[]{
                    new DefaultTreeNode("USA",
                            Arrays.asList(new TreeNode[]{new DefaultTreeNode("New York"),new DefaultTreeNode("Los Angelas")})),
                    new DefaultTreeNode("Japan",
                            Arrays.asList(new TreeNode[]{new DefaultTreeNode("Tokyo"),new DefaultTreeNode("Kyoto")})),
                    new DefaultTreeNode("New Zealand",
                            Arrays.asList(new TreeNode[]{new DefaultTreeNode("Auckland"),new DefaultTreeNode("Queenstown")}))}
            )));
    ]]></zscript>
    <cascader width="300px" model="${treeModel}"/>

Users can select in layers, and the selected items are converted into text. (Default: joining by slashes, i.g. “A/B/C”)

Custom Item Rendering

Since this component has no child component like Listbox, if you want to render its items differently, there 2 ways:

Change text

If you just want to change the text e.g. enclosing it with brackets, just put 

      <>  
              <template name="model">[${each}]</template>  
      </>
  • The template only allows text that can be converted into a ZK Label.

Change HTML Structure

If you want to make more changes e.g. adding tooltips by setting title attributes, you need to create your own ItemRenderer. See ZK_Developer’s_Reference/mvc/View/Renderer/Item_Renderer.

Properties

Disabled

Sets whether it is disabled. A disabled component can’t interact with users.

ItemConverter

Specify a full qualified class name that implements org.zkoss.util.Converter. The default implementation is joining all the toString() result of items by slashes /.

By implementing your own one, you can generate a custom text that represents the selected item.

Custom Item Rendering

Since this component has no child component like Listbox, if you want to render its items differently, there 2 ways:

Change text

If you just want to change the text e.g. enclosing it with brackets, just put 

      <>  
              <template name="model">[${each}]</template>  
      </>
  • The template only allows text that can be converted into a ZK Label.

Change HTML Structure

If you want to make more changes e.g. adding tooltips by setting title attributes, you need to create your own ItemRenderer. See ZK_Developer’s_Reference/mvc/View/Renderer/Item_Renderer.

Model

The tree model associated with this cascader.

Open

Drops down or closes the list of items.

Placeholder

When the selected item is empty, the placeholder text would be displayed. (Default: empty)

SelectedItem

Represents the selected item, or null if no item is selected.

Items are selected only if the leaf item is selected. For example, in an A - B - C structure, selected item remains null until the leaf node C is selected.

Supported Events

Name

Event Type

onAfterRender

Event: [org.zkoss.zk.ui.event.Event](https://www.zkoss.org/javadoc/latest/zk/org/zkoss/zk/ui/event/Event.html)

onSelect

Event: [org.zkoss.zk.ui.event.SelectEvent](https://www.zkoss.org/javadoc/latest/zk/org/zkoss/zk/ui/event/SelectEvent.html)

Represents an event caused by user's the selection changed at the client.

onOpen

Event: [org.zkoss.zk.ui.event.OpenEvent](https://www.zkoss.org/javadoc/latest/zk/org/zkoss/zk/ui/event/OpenEvent.html)

Represents an event that indicates an open state that is changed at the client.

Supported Children

* None