IndexedDB Webcast In GDL-IL

Here is a short webcast that shows how to build “IndexedDB in a jQueryMobile app”. If you thought about building a modern web application with offline capabilities, it will be a good 101 session for you. For the full code you can read “How to use indexedDB” and here is a live demo of this mobile web app. It seems that with the JavaScript shim that I’m using this is a nice solution for developers that wish to target both Android and iOS as it should work in both Chrome for android and mobile safari. Moreover, soon when IE10 will be in the ‘wild’ web, indexedDB API will be available in Chrome, FF and IE, nice ahh?

Btw, one of the reader of the blog point me to another open source IndexedDB API wrapper library – From browsing it, it’s looking good!

How To Use IndexedDB – Simple(st) Example

In the past few months, I’ve saw many developers that use  local storage for ‘big data’ on the client side. Local storage is a powerful API that let developer save key-value data on the browser. However, it’s got some limitation like: synchronize operation that make it less efficient when it’s heavily used. Moreover, it should replace simple cases (e.g. saving the user state) and not in scenarios where you wish to save lots of data and then have the ability to ‘slide and dice’ it base on your needs with effiency. For that, we used to have WebSQL (which as you know is deprecated from 2010) and the new cool kid in town – IndexedDB. Here I will try to give you a short example that will run nicly both on IE10, Firefox (that match the spec) and Chrome (which need to tune a bit the setVersion update to call onupgrade). IE10 will support IndexedDB as well – so it’s great news to web developers in terms of ‘wild’ support for this important API in browsers. I wish we will see soon Safari (specially, on the mobile) match Chrome for android and give us the ability to leverage indexedDB both on Android and iOS.

Ok, as Linus said: “talking is cheap, show me some code”… Let’s go over the example code. In this example we will save todos to keep things simple. Classic, no? In the end of the post, I will also give two other examples of a ‘todo app’ the use indexedDB, WebSQL and jQueryMobile.

IndexedDB Changes – SetVersion Is Out

Well, things are moving fast… We have now a new version for handling updating schema in IndexedDB. As you can see both MDN (mozilla) and Chrome/Chromium are aligned with the new way.

Here is a short example that show you the new way to work with upgrades to your schema:

The full example I have on github that show the differences between WebSQL and indexedDB still uses the setVersion syntax. However, in Firefox 10 (and in Chrome 21) you should change your code to work with the new API. Good luck!

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[Update Sep 2012]

In case you wish to see a code that will work fine both on Chrome (that still need to update according to the spec on onupgrade) and Firefox you can check this example of jQuery mobile and indexedDB mobile app: