Example usage of serviceworker-cache-wrapper.js

serviceworker-cache-wrapper-example.js

var jsonDataRe = /example\.com\/(.*\.json)/;

self.addEventListener('fetch', function(event) {
    var request = event.request,
        match = jsonDataRe.exec(request.url);

    if (match) {
        // Use regex capturing to grab only the bit of the URL
        // that we care about, ignoring query string, etc.
        var cacheKey = match[1];
        event.respondWith(
            cacheGet(cacheKey).then(function(response) {
                return response || fetch(request).then(function(response) {
                    cachePut(cacheKey, request, response.clone());
                    return response;
                });
            })
        );
    }
});

See http://www.holovaty.com/writing/service-worker-cache-names/ for explanation.