Extend HTML compressor to compress and combine external files

Hello,

I'm compressing HTML files referencing external CSS and Javascript scripts. I 
would like to set a particular compressor to the HTMLCompressor through Java 
API that is used each time an external script is detected.

My compressor will be in charge to load the files thanks to the given paths, 
compress and combine it and then return the new path to add as external script.

API proposal:

// new interface
interface ExternalCompressor {
   String compress(List<String> path, Compressor defaultCompressor);
}

// new setter
htmlCompressor.setExternalCompressor((paths, defaultCompressor) -> {
    // implementation sample skeleton
    paths.forEach((path) -> {
        File f = new File(baseDir, path);
        String content = ...
        defaultCompressor.compress(content);
        ...
    }

    return combinedPath;
});

Result:

<html>
<head>
<link rel="bar.css" />
<script src="foo.js" />
</head>
<body>
<script src="bottom1.js" />
<script src="bottom2.js" />
</body>
</html>

// gives
<html>
<head>>
<link rel="/custom-path/bar.min.css" />
<script src="/custom-path/foo.min.js" /
</head>
<body>
<script src="/custom-path/combine.min.js" /
</body>
</html>

Thanks!

Original issue reported on code.google.com by guidro...@gmail.com on 21 Feb 2014 at 1:50

liuzhe1218 / htmlcompressor

Extend HTML compressor to compress and combine external files #92