JSF-f：attribute

h：attributeタグは、コンポーネントに属性値を渡すオプション、またはアクションリスナーを介してコンポーネントにパラメーターを渡すオプションを提供します。

JSFタグ

<h:commandButton id = "submit"
   actionListener = "#{userData.attributeListener}" action = "result">
   <f:attribute name = "value" value = "Show Message"/>
   <f:attribute name = "username" value = "JSF 2.0 User"/>
</h:commandButton>

タグ属性

S.No

Attribute & Description

1

name

設定する属性の名前

2

value

属性の値

応用例

上記のタグをテストするテストJSFアプリケーションを作成しましょう。

Step	Description
1	Create a project with a name helloworld under a package com.finddevguides.test as explained in the JSF - First Application chapter.
2	Modify home.xhtml as explained below. Keep rest of the files unchanged.
3	Create result.xhtml in the webapps directory as explained below.
4	Create UserData.java as a managed bean under package com.finddevguides.test as explained below.
5	Compile and run the application to make sure business logic is working as per the requirements.
6	Finally, build the application in the form of war file and deploy it in Apache Tomcat Webserver.
7	Launch your web application using appropriate URL as explained below in the last step.

UserData.java

package com.finddevguides.test;

import java.io.Serializable;

import javax.faces.bean.ManagedBean;
import javax.faces.bean.SessionScoped;

@ManagedBean(name = "userData", eager = true)
@SessionScoped
public class UserData implements Serializable {
   private static final long serialVersionUID = 1L;
   public String data = "1";

   public String getData() {
      return data;
   }

   public void setData(String data) {
      this.data = data;
   }

   public void attributeListener(ActionEvent event) {
      data = (String)event.getComponent().getAttributes().get("username");
   }
}

home.xhtml

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
   "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns = "http://www.w3.org/1999/xhtml">
   <head>
      <title>JSF Tutorial!</title>
   </head>

   <body>
      <h2>f:attribute example</h2>
      <hr/>

      <h:form>
         <h:commandButton id = "submit"
            actionListener = "#{userData.attributeListener}" action = "result">
            <f:attribute name = "value" value = "Show Message"/>
            <f:attribute name = "username" value = "JSF 2.0 User"/>
         </h:commandButton>
      </h:form>

   </body>
</html>

result.xhtml

<?xml version = "1.0" encoding = "UTF-8"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns = "http://www.w3.org/1999/xhtml"
   xmlns:f = "http://java.sun.com/jsf/core"
   xmlns:h = "http://java.sun.com/jsf/html"
   xmlns:ui = "http://java.sun.com/jsf/facelets">

   <head>
      <title>JSF Tutorial!</title>
   </head>

   <h:body>
      <h2>Result</h2>
      <hr/>
      #{userData.data}
   </h:body>
</html>

すべての変更を完了したら、JSF-最初のアプリケーションの章で行ったようにアプリケーションをコンパイルして実行します。すべてがアプリケーションで問題ない場合、次の結果が生成されます。

JSF h：attribute

[メッセージを表示]ボタンを押すと、次の結果が表示されます。

JSF h：attribute1

Jsf-attribute-tag