如何确定内置组件的渲染器 [英] How do I determine the renderer of a built-in component

问题描述

我想为内置组件创建自定义渲染器:<h:selectOneRadio /> 我想知道，如何确定内置组件的渲染器，以便创建自己的组件并从中扩展?

I want to create a customized renderer for a built-in component: <h:selectOneRadio /> I would like to know, how do I determine the renderer for a built-in component in order to create my own one and extend from it?

我想知道一种获取它的机制，因此我可以将其应用于确定任何其他内置组件的渲染器，而不仅仅是确定<h:selectOneRadio />的渲染器.

I would like to know a mechanism to get it so I could apply it to determine the renderer for any other built-in component and not just for <h:selectOneRadio />.

谢谢

推荐答案

标准JSF组件的呈现器类特定于实现(Mojarra和MyFaces各自具有自己的实现)，并在特定于实现的情况下注册为<renderer> faces-config.xml(或它的工件).

The renderer class of a standard JSF component is implementation specific (Mojarra and MyFaces have each its own implementation) and is registered as <renderer> in the implementation-specific faces-config.xml (or an artifact of it).

要找出答案，您基本上首先需要了解组件系列和渲染器类型，以便您可以自己在实现特定的faces-config.xml文件中查找渲染器类.

To find it out, you basically need to know the component family and renderer type first, so that you can lookup the renderer class in the implementation-specific faces-config.xml file youself.

您的起点是 javax.faces.component.html包裹摘要. <h:selectOneRadio>由 组件类. 其Javadoc 的介绍性文本说:

Your starting point is the javax.faces.component.html package summary. The <h:selectOneRadio> is represented by the HtmlSelectOneRadio component class. The introductory text of its javadoc says:

默认情况下，rendererType属性必须设置为"javax.faces.Radio".

存在渲染器类型.

在COMPONENT_FAMILY常量. /html/HtmlSelectOneRadio.html#field.summary"rel =" nofollow noreferrer>相同的javadoc .单击以访问常量字段值" :

The component family is specified as COMPONENT_FAMILY constant under "Fields inherited from UISelectOne" section of the very same javadoc. Click through to "Constant field values":

public static final java.lang.String COMPONENT_FAMILY"javax.faces.SelectOne"

有组件族.

现在，我们应该查看特定于实现的faces-config.xml文件(或其文件).不幸的是，它的位置/名称没有记录在任何地方，但是我可以确定，在Mojarra的情况下，它是实现JAR文件中的com/sun/faces/jsf-ri-runtime.xml文件(您可以使用zip工具提取JAR文件).打开它并查找与组件族javax.faces.SelectOne和渲染器类型javax.faces.Radio相匹配的<renderer>条目:

Now, we should look in the implementation-specific faces-config.xml file (or an artifact of it). Its location/name is unfortunately nowhere documented, but I can tell that in case of Mojarra it is the com/sun/faces/jsf-ri-runtime.xml file in the implementation JAR file (you can extract JAR files with a zip tool). Open it and look for a <renderer> entry matching the component family javax.faces.SelectOne and renderer type javax.faces.Radio:

<renderer>
    <component-family>javax.faces.SelectOne</component-family>
    <renderer-type>javax.faces.Radio</renderer-type>
    <renderer-class>
         com.sun.faces.renderkit.html_basic.RadioRenderer
    </renderer-class>
</renderer>

最后是它:

Finally there is it: the com.sun.faces.renderkit.html_basic.RadioRenderer.

请注意，正是严格地扩展了该类，才能将您的自定义渲染器与特定的JSF实现耦合.您的渲染器无法在其他实现(例如MyFaces)上重复使用.为了实现独立，您需要自己编写扩展javax.faces.renderer.Renderer的整个渲染器.

Please note that extending exactly that class tight couples your custom renderer to the specific JSF implementation. Your renderer would not be reuseable on a different implementation such as MyFaces. To be implementation independent, you'd need to write the entire renderer yourself which extends javax.faces.renderer.Renderer.

• 如何查找组件- JSF组件的族和渲染器类型
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• How to findout component-family and renderer-type of a JSF component
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