logo offline web applications google gears jia liu [email protected]
Post on 20-Dec-2015
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From Online to Offline
Online applications are Great
Offline are also Necessary Internet unavailable? Don’t want the data in the clouds? Response time?
Fill the gaps between online and offline
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Browser
Text
Server
Database
HTTP
Architecture
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Browser
Text
Server
Database
Install
Architecture
LocalServer
Database
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Browser
Text
Server
Database
Architecture
LocalServer
Database
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Offline Tools
In the past Dojo Storage, Derby/JavaDB, Zimbra
Today Adobe AIR Google Gears Microsoft Silverlight
Coming Soon FireFox 3 HTML5 Working Draft Client-side database storage
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Google Gears
What is Google Gears? Brower-plugin
Open source library http://gears.google.com
Cost Open Source Lightweight installation necessary Application stays completely in the
browser, no extra app/start up
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Components
Local SeverLet web applications interact naturally with your desktop
DatabaseStore data locally in a fully-searchable database
WorkerPoolRun JavaScript in the background to improve performance
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LocalServer
Specialized URL Cache Requests for URLs in the LocalServer’s cache are
intercepted and served locally from the user’s disk
RecourseStore (Manual Update) ManagedResourceStore (Automatic Update)
Manifest File
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DataBase
Open source SQLite Database
Simplified SQL Syntax
Full-text Search
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Workerpool
Time-intensive processes can be run in the background
UI stays responsive/browser doesn’t block No warning dialog “Unresponsive Script”
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Syncing
Globally Unique ID
Timestamps
When Collisions Last one wins
Lock/Check out Let user decide
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Example
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Example
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Applications
Gmail
Calendar
Maps
SpreadSheet
Reader
Google Gears
Docs
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Applications
Gmail, Calendar… Any Web applications that can store data
enough locally to work offline will benefit from it.
Limitations Stock Trading Systems -Online connectivity is an absolute must
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CONCLUSION
Google Gears allows Web application to run offline
It opens a lot of doors to developers looking to bridge the narrowing gap between desktop and web-based applications.
