Question

我已经构建了一个自定义组件按钮，但不知何故该动作未被调用。在组件中调试getAction-Method并调用提供的MethodeExpression时，将按预期调用Bean-Method。但由于某种原因，在浏览器中按下按钮时不会调用Expression。

是否需要某种额外的接口才能将操作传递给嵌入式按钮组件？

任何帮助都非常受欢迎，因为我现在已经陷入这个问题了几天

MyClass的：

public class MyClass extends UIPanel implements SystemEventListener
{

private UIForm              form;
private HtmlCommandButton   buttonOk;

public MyClass()
{
    FacesContext context = getFacesContext();
    UIViewRoot root = context.getViewRoot();
    root.subscribeToViewEvent(PostAddToViewEvent.class, this);
}


@Override
public void processEvent(SystemEvent event)
{
    this.form = new UIForm();
    this.buttonOk = new HtmlCommandButton();
    this.buttonOk.setId("okButtonId");
    this.buttonOk.setActionExpression(getAction());
    this.buttonOk.setValue("OK");
    this.form.getChildren().add(this.buttonOk);
    getChildren().add(this.form);
}


private enum PropertyKeys
{
    action, text, titel
}


public MethodExpression getAction()
{
    return (MethodExpression) getStateHelper().eval(PropertyKeys.action);
}


public void setAction(MethodExpression actionExpression)
{
    getStateHelper().put(PropertyKeys.action, actionExpression);
}


public String getText()
{
    return (String) getStateHelper().eval(PropertyKeys.text);
}


public void setText(String text)
{
    getStateHelper().put(PropertyKeys.text, text);
}


public String getTitel()
{
    return (String) getStateHelper().eval(PropertyKeys.titel);
}


public void setTitel(String titel)
{
    getStateHelper().put(PropertyKeys.titel, titel);
}


@Override
public void encodeAll(FacesContext context) throws IOException
{
    ResponseWriter writer = context.getResponseWriter();
    writer.startElement(HTML.DIV_ELEM, this);
    writer.writeText(getText(), null);
    this.form.encodeAll(context);
    writer.endElement(HTML.DIV_ELEM);
}


@Override
public void encodeChildren(FacesContext context) throws IOException
{

}


@Override
public boolean isListenerForSource(Object source)
{
    return (source instanceof MyClass);
}

}

MyClassHandler：

public class MyClassHandler extends ComponentHandler
{

public MyClassHandler(ComponentConfig config)
{
    super(config);
}


@SuppressWarnings("rawtypes")
@Override
protected MetaRuleset createMetaRuleset(Class type)
{
    return super.createMetaRuleset(type).addRule(new MethodRule("action", String.class, new Class[] { ActionEvent.class }));
}

}

myView方法：

...
public String myMethod()
{
    System.err.println("myMethod");
    return "/some/path/yadayada.xhtml";
}
...

MyView.xhtml

<myTag action="#{myView.myMethod}" id="id1" titel="bla" text="bleh" />

Answer 1

Exdending UICommand就足够了，因为你只需要执行一个动作。

您必须通过tag-attributes提供两个额外的MethodExpressions，并且在decode-method中，您可以检查已按下哪个按钮，并将特定的MethodExpression重定向到UICommand提供的标准操作。这样，您就不必担心遗留接口ActionSource或广播事件的方式。

public void decode(FacesContext contex)
{
    Map<String,String> map = context.getExternalContext.getRequestParameterMap();
    // your rendered buttons need a name you check for
    final boolean okPressed = map.containsKey( getClientId + ":ok" ); 
    final boolean cancelPressed = map.containsKey( getClientId + ":cancel" );
    if(okPressed || cancelPressed)
    {
        MethodExpression exp = null;
        if(okPressed)
        {
            exp = getActionOk();
        }
        else
        {
            exp = getActionCancel();
        }
        // redirect to standard action
        setActionExpression(exp);
        queueEvent(new ActionEvent(this));
    }
}

为了使用它，你需要两个使用Method Expressions（setter和getter）的属性（actionOk和actionCancel）。这些必须由ComponentHandler配置，就像对action-attribute一样。

带按钮的JSF自定义面板 - 未调用操作

1 个答案: