Google Gears is an open-source project designed to enhance web applications by enabling offline capabilities through local storage and various APIs like database and geolocation. It allows developers to create more responsive applications by running resource-intensive tasks asynchronously in a worker pool. However, the project has limitations such as no DOM access and is facing a lack of recent updates and documentation.

1. Google

2. What is it? Google quote “Gears is an open source project that enables more powerful web applications, by adding new features to web browsers.”

3. Gears Application Application that passes javascript calls to the OS Written in java. http://code.google.com/p/gears/ Bsd license

4. Google client gears_init.js Supports: Android, chrome, firefox, safari, ie, opera 1.5 years old Wifi-based geo-location october/2008 Safari support september/2008 http://code.google.com/apis/gears/ Wordpress, zoho, gmail

5. Google’s self proclaimed features LocalServer LocalServer Cache and serve application resources (HTML, JavaScript, images, etc.) locally Database Database Store data locally in a fully-searchable relational database WorkerPool WorkerPool Make your web applications more responsive by performing resource-intensive operations asynchronously

6. Getting started <script src=&quot;gears_init.js&quot;></script> <script> if (!window.google || !google.gears) { location.href = &quot;http://gears.google.com/?action=install&message=<your welcome message>&quot; + &quot;&return=<your website url>&quot;; } </script>

7. Parameters action: Enables applications to customize the Gears install page to provide context during the installation process. There are two allowed values: install or upgrade. Use the install value to prompt the user to install Gears. Use the upgrade parameter if you detect that the version of Gears the user has installed is too old for your application (but note that Gears autodates itself, so typically the vast majority of users all have the latest version). Either of these values enable the rest of the customization parameters. icon_src: Provide the URL to a 48x48 icon for your application. The icon can be any format displayable by web browsers. name: Provide the name of your application. This value can be up to 150 characters in length. message: Provide any text up to 150 characters. This message appears at the top of the installation page. For example: &quot;Install Gears to enable MyGreatApp's offline features!&quot; return: Provide your application's URL. The user will be directed back to this URL when installation is complete.

8. Offline mode Google gears allow the user to store copies of the website files locally. Javascript Html Pictures Even renderings of server side code.

9. How it works Json file Initiate localserver. Create a store. Add to the store by version. Updates are completed via version number. Discussion point - cache

10. Dynamic Ok, getting index is cool. But nothing is dynamic. SQLite!

11. No data Layer

12. SqlLite data layer

13. More options = more work.

14. The perfect solutions

15. Main supported classes beta.database Database beta.desktop Desktop beta.geolocation Geolocation beta.httprequest HttpRequest beta.localserver LocalServer beta.timer Timer beta.workerpool WorkerPool

16. beta.database Database var db = google.gears.factory.create('beta.database'); db.open('database-test'); db.execute('create table if not exists Test' + ' (Phrase text, Timestamp int)');

17. Desktop var desktop = google.gears.factory.create('beta.desktop'); desktop.createShortcut('Test Application', 'http://example.com/index.html', {'128x128': 'http://example.com/icon128x128.png', '48x48': 'http://example.com/icon48x48.png', '32x32': 'http://example.com/icon32x32.png', '16x16': 'http://example.com/icon16x16.png'}, 'An application at http://example.com/index.html '); Files upload

18. GeoLocation var geo = google.gears.factory.create('beta.geolocation'); Read only

19. HttpRequest var request = google.gears.factory.create('beta.httprequest'); request.open('GET', '/index.html'); request.onreadystatechange = function() { if (request.readyState == 4) { console.write(request.responseText); } }; request.send(); Basically created specifically for the worker pool because it cant use the XmlHttpRequest.

20. Worker pool The WorkerPool API runs operations in the background, without blocking the UI. Scripts executing in the WorkerPool will not trigger the browser's &quot;unresponsive script&quot; dialog.

21. Worker pool declaration var workerPool = google.gears.factory.create('beta.workerpool'); var childWorkerId = workerPool.createWorkerFromUrl('worker.js');

22. isolation Collection of processes, not threads. No inheritance, no variable sharing, no share namespace Interact via message objects

23. limitations No DOM access Document window Most other functions are supported

24. Usage patern create a WorkerPool (wp) Indicate where messages will go (wp.onmessage) Create worker wp.createWorkerFromUrl() Function returns immediately, parent continues too run.

25. State No new blog post in the last 6 months Api documentation missing. Very interesting market change ?