HistoryPopStateEvent

HistoryPopStateEvent

• Demonstration: N/A
• Java API: HistoryPopStateEvent
• JavaScript API: N/A

Employment/Purpose

The history pop state event used with onHistoryPopState to notify that user pressed BACK, FORWARD or others that causes the history changed (but still in the same desktop).

All root components of all pages of the desktop will receives this event.

Example

The example shows how to push a history state and handle a HistoryPopStateEvent object.

<zk>
  <tabbox id="tb" height="300px">
    <attribute name="onSelect"><![CDATA[
      Tab selected = event.getReference();
      int selectedIndex = selected.getIndex();
      desktop.pushHistoryState(Collections.singletonMap("tabIndex", selectedIndex), "", "/" + selectedIndex);
    ]]>
    </attribute>
    <attribute name="onHistoryPopState"><![CDATA[
      Map state = event.getState();
      if (state != null)
        tb.setSelectedIndex(state.get("tabIndex"));
    ]]>
    </attribute>
    <tabs id="tabs">
      <tab id="A" label="Tab A" />
      <tab id="B" label="Tab B" />
      <tab id="C" label="Tab C" />
      <tab id="D" label="Tab D" />
      <tab id="E" label="Tab E" />
    </tabs>
    <tabpanels>
      <tabpanel>This is panel A</tabpanel>
      <tabpanel>This is panel B</tabpanel>
      <tabpanel>This is panel C</tabpanel>
      <tabpanel>This is panel D</tabpanel>
      <tabpanel>This is panel E</tabpanel>
    </tabpanels>
  </tabbox>
</zk>

• Line 6: Use Desktop.pushHistoryState(Object, String, String) to push a history state.
• Line 9: Listen onHistoryPopState on any root component to handle HistoryPopStateEvent object.

You can handle events in an MVC fashion.

public class TestComposer extends SelectorComposer<Tabbox> {
  @Wire
  private Tabbox tb;
  
  @Listen("onHistoryPopState = #tb")
  public void handleHistoryPopState(HistoryPopStateEvent event) {
    Map state = (Map) event.getState();
    if (state != null) {
      tb.setSelectedIndex((int) state.get("tabIndex"));
    }
  }
}

• Line 5: Listen the onHistoryPopState event of the root component #tb.

Or you can use a special annotition HistoryPopState if you prefer MVVM.

public class TestVM {
  private int selectedIndex = 0;
  
  public int getSelectedIndex() {
  	return selectedIndex;
  }
  
  public void setSelectedIndex(int index) {
    selectedIndex = index;
    Desktop desktop = Executions.getCurrent().getDesktop();
    desktop.pushHistoryState(Collections.singletonMap("tabIndex", selectedIndex), "", "/" + selectedIndex);
  }

  @HistoryPopState
  @SmartNotifyChange("selectedIndex")
  public void handleHistoryPopState(@ContextParam(ContextType.TRIGGER_EVENT) HistoryPopStateEvent event) {
    Map state = (Map) event.getState();
    if (state != null) {
      selectedIndex = ((int) state.get("tabIndex"));
    }
  }
}

• Line 14: a method annotated with HistoryPopState can handle HistoryPopStateEvent.

Supported events

Name	Event Type
None	None

Supported Children

*NONE

Use cases

Version	Description	Example Location

Version History

Version	Date	Content
8.5.0	Oct 2017	ZK-3711: Support HTML5 history API