Is it possible to include all javascripts files from one folder in JSF?

Question

I am using JSF 2.0, and am looking for a means to include all the javascripts from a given folder on a page, i.e. do something like

Answer 1

Nice idea. This is not supported by the JSF API, but it's in theory possible with a custom script renderer. I played somewhat around it and it's indeed possible. Just create a MultiScriptRenderer which extends ScriptRenderer and override encodeEnd() to check if the name attribute contains the * wildcard and then handle accordingly by scanning for files matching this pattern in the resources folder.

Here's a kickoff example:

package com.example;

import java.io.File;
import java.io.FileFilter;
import java.io.IOException;
import java.util.Map;
import javax.faces.component.UIComponent;
import javax.faces.context.FacesContext;
import com.sun.faces.renderkit.html_basic.ScriptRenderer;

public class MultiScriptRenderer extends ScriptRenderer {

    @Override
    public void encodeEnd(FacesContext context, UIComponent component) throws IOException {
        Map attributes = component.getAttributes();
        String name = (String) attributes.get("name");
        if (name.contains("*")) {
            String pattern = name.replace(".", "\\.").replace("*", ".*");
            String library = (String) attributes.get("library");
            File root = new File(context.getExternalContext().getRealPath("/resources/" + (library != null ? library : "")));
            for (File file : root.listFiles()) {
                if (file.getName().matches(pattern)) {
                    attributes.put("name", file.getName());
                    super.encodeEnd(context, component);
                }
            }
            attributes.put("name", name); // Put original name back. You never know.
        } else {
            super.encodeEnd(context, component);
        }
    }
}

Register it in faces-config.xml as follows (Sorry, @FacesRenderer annotation isn't going to work until it's fixed in JSF 2.2 for this specific corner case, see also JSF issue 1748):

    
        javax.faces.Output
        javax.faces.resource.Script
        com.example.MultiScriptRenderer
    

Works fine on Mojarra 2.0.3 here. You can use patterns like *.js and prefix*.js. The particular code example is only tight coupled to a specific JSF implementation to save code boilerplate. It also requires that the WAR is expanded on deploy, otherwise browsing the directory by File#listFiles() won't be possible (which thus excludes certain (older) servletcontainer versions/configurations). For other JSF implementations you'll have to extend its ScriptRenderer instead, or write a whole new one if you want to be implementation independent (which should be pretty simple though, just look at standard ScriptRenderer source if you stucks).