Add support for cross-tab notifications

[thgreasi]

As noted in:
localForage/localForage#104
localForage/localForage#244
localForage/localForage#622

[dmurph]

Indexedb observers are now working behind a flag in Canary

[thgreasi]

That's great. I'm thinking about an initial release using localstorage to propagate cross tab events. After IndexedDB events gets implemented without a flag from one more browser engine, we can plan upgrading the architecture.

[TheNeikos]

Thanks a lot for working on this!

[dmurph]

Awesome! If you have any time to take a look at the current API (see sample here:
https://googlechrome.github.io/samples/indexeddb-observers/) any feedback would be greatly appreciated.

[thgreasi]

Just opened PR #6. It would be great to receive some feedback and then release during the weekend.

[thgreasi]

Just meged #6 and released v1.1.0 which includes cross-tab observation.

[TheNeikos]

Thanks a lot. Going to implement this now

[deiu]

Hi! Is this feature supported in all browsers? It would be useful to have a note in the README about current browser support.

Also, are there any plans to merge this feature into the main repo?

Edit: I'm only interested in support for IndexedDB, not localStorage.

[thgreasi]

@deiu This is based on localStorage events, so it should work wherever localStorage is supported.
My main concern would be private browsing, which essentially beats the purpose, since the user by definition requests for an isolated tab, so this should be a non-issue.

[deiu]

Thanks for the quick reply! I see. I knew the eventListener for localStorage is available but for some reason I'm thinking by default of IndexedDB when using localForage. After reading the thread again, I see you mentioned waiting for native IndexedDB support in browsers.