在 JavaScript 文件中混合 JSF EL

Mixing JSF EL in a JavaScript file

提问by user283680

Is there a way to have Expression Language(EL) expressions included JavaScript files be evaluated by JSF?

有没有办法让JSF评估包含JavaScript文件的表达式语言（EL）表达式？

I was hoping that Seam might have a way around this, but no luck so far. All I want is to be able to use localized messages in my JavaScript functions which are shared across pages.

我希望 Seam 可以解决这个问题，但到目前为止还没有运气。我想要的只是能够在跨页面共享的 JavaScript 函数中使用本地化消息。

回答by BalusC

Five ways:

五种方式：

1. Declare it as global variable in the parent JSF page.

   <script type="text/javascript" src="script.js"></script>
   <script type="text/javascript">
       var messages = [];
       <ui:repeat value="#{bean.messages}" var="message">
           messages['#{message.key}'] = '#{message.value}';
       </ui:repeat>
   </script>
   

   Or, if it's in JSON format already.

   <script type="text/javascript" src="script.js"></script>
   <script type="text/javascript">var messages = #{bean.messagesAsJson};</script>
   

2. Put the whole <script>in a XHTML file and use ui:includeto include it.

   <script type="text/javascript" src="script.js"></script>
   <ui:include src="script-variables.xhtml" />
   

3. Pass *.jsthrough the JspServlet(only if it's enough to evaluate only the ${}expressions). E.g. in web.xml(the <servlet-name>of JspServletcan be found in web.xmlof the servletcontainer in question, it's usually jsp).

   <servlet-mapping>
       <servlet-name>jsp</servlet-name>
       <url-pattern>*.js</url-pattern>
   </servlet-mapping>
   

4. Make use of "good old" JSP with a modified content type. Rename script.jsto script.jspand add the following line to top of JSP (only if it's enough to evaluate only the ${}expressions):

   <%@page contentType="text/javascript" %>
   

5. Let JS obtain the data ajaxically during load. Here's a jQuerytargeted example.

   $.getJSON('json/messages', function(messages) {
       $.each(messages, function(key, value) {
           $.messages[key] = value;
       });
   });
   

1. 在父 JSF 页面中将其声明为全局变量。

   <script type="text/javascript" src="script.js"></script>
   <script type="text/javascript">
       var messages = [];
       <ui:repeat value="#{bean.messages}" var="message">
           messages['#{message.key}'] = '#{message.value}';
       </ui:repeat>
   </script>
   

   或者，如果它已经是 JSON 格式。

   <script type="text/javascript" src="script.js"></script>
   <script type="text/javascript">var messages = #{bean.messagesAsJson};</script>
   

2. 将整个<script>文件放在一个 XHTML 文件中并使用ui:include它来包含它。

   <script type="text/javascript" src="script.js"></script>
   <ui:include src="script-variables.xhtml" />
   

3. 通*.js过JspServlet（只有当它足以只评价${}表达式）。例如，在web.xml（对<servlet-name>中JspServlet可以发现web.xml有问题的servletcontainer的，它通常是jsp）。

   <servlet-mapping>
       <servlet-name>jsp</servlet-name>
       <url-pattern>*.js</url-pattern>
   </servlet-mapping>
   

4. 使用具有修改内容类型的“好旧”JSP。重命名script.js为script.jsp并将以下行添加到 JSP 的顶部（仅当它足以仅计算${}表达式时）：

   <%@page contentType="text/javascript" %>
   

5. 让JS在加载时ajax方式获取数据。这是一个针对jQuery 的示例。

   $.getJSON('json/messages', function(messages) {
       $.each(messages, function(key, value) {
           $.messages[key] = value;
       });
   });
   

回答by timr

Since I don't like techniques that won't let the browser cache the localized Strings, I used the following technique to localize JavaScript alerts, etc. It seems a good fit if the Strings that you need in your JavaScript code are different from the ones needed by the Web server:

由于我不喜欢不允许浏览器缓存本地化字符串的技术，因此我使用了以下技术来本地化 JavaScript 警报等。如果您在 JavaScript 代码中需要的字符串与Web服务器需要的：

<h:head>
    <h:outputScript library="javascript" name="#{fw.JsFwStrings}" />
    ...

I then assign the resource string JsFwStrings to the filename of the JavaScript file defining the localized strings for the given language.

然后我将资源字符串 JsFwStrings 分配给定义给定语言的本地化字符串的 JavaScript 文件的文件名。

For example, the fw_en.properties file contains the entry JsFwStrings=JsFwStrings_en.js

例如，fw_en.properties 文件包含条目 JsFwStrings=JsFwStrings_en.js

And the JsFwStrings_en.js file contains

并且 JsFwStrings_en.js 文件包含

var TosFramework = TosFramework || {};
TosFramework.Strings = {
    UnSavedChangesWarning : 'You have unsaved changes.',
    CancelConfirmQuestion : 'Are you sure you want to cancel?'
}