We’ve created a quick and simple to-do app that works offline and that runs in all major modern browsers, thanks to both IndexedDB and WebSQL (via a polyfill).
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What user journey and technical implemention might to make the offline experience optional? Implementing opt-in is relatively easy. Implement a mechanism to uninstall the application.
- Hint for AppCache: If the manifest itself returns a 404 or 410, the cache is deleted.
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Currently, whenever a todo is created or deleted the application throws away everything on screen, loads all todos from the database and puts them in the DOM.
- Make this more efficient.
- We've cheated a bit (for reasons that will become clearer in the next section) and used the created timestamp as the key for todos. IndexedDB also supports auto-incrementors.
- Create a new version of the database that uses an incrementor for the
_idand write a migration withinonupgradeneededthat changes the structure of the database to use an auto-incrementor and updates the data to use the new index. - What happens if you have two tabs open and one tab upgrades to the new schema and javascript whilst the other is still expecting the old schema?
- Create a new version of the database that uses an incrementor for the
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