Delete old caches on activate.

[tulioag]

Based on https://googlechrome.github.io/samples/service-worker/custom-offline-page/

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This change is 

[vlukashov]

Reviewed 1 of 1 files at r1.
Reviewable status: all files reviewed, 6 unresolved discussions (waiting on @tulioag)

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src/main/webapp/sw.js, line 2 at r1 (raw file):

// Important: update the version each time you change any of the files listed below
var version = 4;

Should it now become 5, not 1 (to avoid possible overlaps with the first "version 1")?

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src/main/webapp/sw.js, line 2 at r1 (raw file):

// Important: update the version each time you change any of the files listed below
var version = 1;

nit: var and const used in the same file. For consistency it would be better to use the es5 syntax all over (i.e. replace all vars with either lets or consts)

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src/main/webapp/sw.js, line 7 at r1 (raw file):

var offlineAssets = [offlinePage, 'manifest.json',
  'images/offline-login-banner.jpg'
]

nit: missing semicolon

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src/main/webapp/sw.js, line 14 at r1 (raw file):

  return caches.open(CACHE_NAME)
    .then(function(cache) {
      cache.addAll(offlineAssets);

The return value of cache.addAll() is ignored. Is that intentional? That can cause the service worker to become installed before the cache is ready (i.e. chance of a race condition).

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src/main/webapp/sw.js, line 14 at r1 (raw file):

    .then(function(cache) {
      cache.add(manifest);
      cache.add(offlinePage);

Is that intentional that the cache busting technique from https://googlechrome.github.io/samples/service-worker/custom-offline-page/ is not used here?

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src/main/webapp/sw.js, line 26 at r1 (raw file):

            // If this cache name isn't present in the array of "expected" cache names,
            // then delete it.
            console.log('Deleting out of date cache:', cacheName);

Do we really need a console log statement?

[tulioag]

Reviewable status: 0 of 2 files reviewed, 4 unresolved discussions (waiting on @vlukashov and @tulioag)

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src/main/webapp/sw.js, line 2 at r1 (raw file):

Previously, vlukashov (Viktor Lukashov) wrote…

Should it now become 5, not 1 (to avoid possible overlaps with the first "version 1")?

Done.

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src/main/webapp/sw.js, line 14 at r1 (raw file):

Previously, vlukashov (Viktor Lukashov) wrote…

Is that intentional that the cache busting technique from https://googlechrome.github.io/samples/service-worker/custom-offline-page/ is not used here?

Added cache busting.

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src/main/webapp/sw.js, line 14 at r1 (raw file):

Previously, vlukashov (Viktor Lukashov) wrote…

The return value of cache.addAll() is ignored. Is that intentional? That can cause the service worker to become installed before the cache is ready (i.e. chance of a race condition).

Thanks for catiching that. The code was refactored due to adding cache bust

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src/main/webapp/sw.js, line 26 at r1 (raw file):

Previously, vlukashov (Viktor Lukashov) wrote…

Do we really need a console log statement?

Removed

[vlukashov]

Reviewed 2 of 2 files at r2.
Reviewable status: complete! all files reviewed, all discussions resolved