Mixing JSF EL in a JavaScript file

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

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.

Solution

Five ways:

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>

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

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

Pass *.js through the JspServlet (only if it's enough to evaluate only the ${} expressions). E.g. in web.xml (the <servlet-name> of JspServlet can be found in web.xml of the servletcontainer in question, it's usually jsp).
```
<servlet-mapping>
    <servlet-name>jsp</servlet-name>
    <url-pattern>*.js</url-pattern>
</servlet-mapping>
```
Make use of "good old" JSP with a modified content type. Rename script.js to script.jsp and add the following line to top of JSP (only if it's enough to evaluate only the ${} expressions):
```
<%@page contentType="text/javascript" %>
```

Let JS obtain the data ajaxically during load. Here's a jQuery targeted example.

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