Cache busting helper

build-versionjs.sh

#!/bin/bash
PROJECTHOME=$(dirname $(dirname $0))
JSSOURCEDIR="$PROJECTHOME/public/js"
VERSIONFILE="$JSSOURCEDIR/version.js"
VERSION=$(git describe --all --long | tr "-" " " | cut -d " " -f 3)

if [ ! -d "$PROJECTHOME" -o ! -d "$JSSOURCEDIR" ];
then
    echo "Unable to resolve PROJECTHOME or JSSOURCEDIR"
    exit 1
fi

if [ ! -f $VERSIONFILE ]
then
    touch $VERSIONFILE
fi

cat > $VERSIONFILE <<JSSOURCE
var getVersion = (function () {
    var version = "$VERSION";
    return function () {
        return version;
    }
}());
JSSOURCE

main.js

var version = (function () {
    "use strict";

    if ("getVersion" in window) {
        return getVersion();
    }

    return Math.random() * 9999;
}());

requirejs.config({
    urlArgs: "v=" + version
});

define(function () {
    "use strict";

    // app init code here
});

This is a script I use to eliminate caching problems, without reverting to random numbers. I place this in <proj.root>/scripts and it generates a file called version.js in <proj.root>/public/js, which is included in the head of my index.html. I use the version in the urlArgs config for requirejs.