交換鏈接的依賴模型對象

Question

上我在完全喪失的類型如何進一步進行：

我有面板採用了DropDownChoice和下一個提交按鈕即可。根據DropDownChoice的選定值（獲取OnChangeAjaxBehavior附加到它後獲得的，提交按鈕需要用不同的替換整個面板，或成爲ExternalLink。）

目前，代碼看起來像即：

public class ReportSelectionPanel extends Panel { 
    protected OptionItem selectedOption ; 
    public ReportSelectionPanel(String id) { 
     super(id); 
     IModel<List<OptionItem>> choices = new AbstractReadOnlyModel() { 
     // Create a list of options to be displayed in the DropDownChoice 
     } ; 

     final IModel<OptionItem> optionModel = 
      new PropertyModel<OptionItem>(this,"selectedOption") ; 

     final DropDownChoice<OptionItem> options = 
      new DropDownChoice("selectChoice",optionModel,choices) ; 

     // I don't know what the button should be... Plain Button? A Link? 
     final Component button = ??? 

     options.add(new OnChangeAjaxBehavior() { 
      protected void onUpdate(AjaxRequestTarget target) { 

        if (selectedOption.getChild() == null) { 
         // button becomes an ExternalLink. 
         // A new window will popup once button is clicked 
        } else { 
         // button becomes a Something, and upon clicking, 
         // this ReportSelectionPanel instance gets replaced by 
         // an new Panel instance, the type of which is 
        // selectedOption.getChild() 
      } 
     }) ; 

我真的不太清楚註釋行應該變成什麼樣達到的效果有什麼建議

感謝

埃裏克

0123？！

Answer 1

恕我直言，這是更好的保持只有一個按鈕，只是不同的反應，這取決於所選擇的選項：

final Component button = new AjaxButton("button") { 
    public void onClick(AjaxRequestTarget target) { 
     if (selectedOption.getChild() == null) { 
      PopupSettings popup = new PopupSettings(); 
      popup.setTarget("'" + externalUrl + "'"); 
      target.appendJavascript(popup.getPopupJavaScript()); 
     } else { 
      ReportSelectionPanel.this.replaceWith(new ReportResultPanel("...")); 
     } 
    } 
}; 

// not needed if options and button are inside a form 
// options.add(new OnChangeAjaxBehavior() { }) ;