Cache busting specific modules with RequireJS

Question

This question has been asked several times but not specific to this example.

Here is an overview of our application:

Simple server routing with Express on Node
Single page backbone application
Core modules and libraries (JS/CSS) that don't change
Widget JS/LESS/HTML files that frequently change

During development, I am looking to cache bust files that change but not those core libraries to speed up my page reloads and quicken my development.

I have found explanations on:

Cache Busting on RequireJS - here
Explanation on Cache Busting Specific Modules - here

Could the solution:

Explain how the requireJS caching busting works?
Provide a solution for this specific scenario.

score 4 · Answer 1 · edited May 23 '17 at 12:16

The cache-busting works by appending an always-unique query string to the end of every file which is required. It makes use of RequireJS's urlArgs config value; RequireJS takes care of appending it for you:

urlArgs: "bust=" + (new Date()).getTime()

The(new Date()).getTime() part is just a simple way to get a unique string out of JavaScript. You could do some variation on Math.random(), but using the number of milliseconds since the epoch guarantees uniqueness, for optimum cache-bustage.

I think Mr Burke is suggesting something like:

require.config({
    baseUrl: '/base/path',
    paths: {
        'fileAlias': 'fileLikelyToChange?bust=' + (new Date()).getTime(),
        'anotherFileAlias': 'anotherFileLikelyToChange?bust=' + (new Date()).getTime(),
        'jQuery': 'jQuery'
    },
});

So, instead of the ubiquitous urlArgs cache-busting, you apply it specifically to each file which is likely to change; hence, excluding any libraries.

I haven't tested it, but I'd probably tidy it up to something like:

function bust(path) {
    return path + '?bust=' + (new Date()).getTime();
}

require.config({
    baseUrl: '/base/path',
    paths: {
        'fileAlias': bust('fileLikelyToChange'),
        'anotherFileAlias': bust('anotherFileLikelyToChange'),
        'jQuery': 'jQuery'
    },
});

Thanks - what about files that are included throughout my application but not referenced in the require.config - paths object? — imrane, May 14 '13 at 14:20
For that scenario, I don't think there is an easy solution. I'm just describing what I think was suggested in the GitHub issue. I don't think you really have any other options, short of modifying RequireJS's source or making an elaborate hack. — c24w, May 14 '13 at 15:39

score 0 · Answer 2 · answered Oct 15 '14 at 18:51

Just remember that if you really need to rely on some external script that you can use $.getScript instead of require to ensure that it's included. I have some non-amd scripts that are for 3rd party integration (e.g. amazon payments), which I used getScript for instead of require. If you can use this method, it would avoid sending the cache busting parameters from urlArgs to the external server.

Cache busting specific modules with RequireJS

2 Answers2