Amplify is a JavaScript library that provides tools for persistent client-side storage, mocking and manipulating AJAX requests, and a publish-subscribe system for messaging. It includes a Store API for cross-browser local storage, a Request API that abstracts data requests and supports caching and decoding, and a Pub/Sub API to subscribe to and publish messages. Amplify is open source under both MIT and GPL licenses.

1. INTRODUCING AMPLIFY
by Scott González

2. GOALS
• Solve real problems based on existing projects
• Easy to drop into existing projects

3. INITIAL FEATURES
• Persistent client-side storage
• Mocking ajax requests
• Manipulating data from ajax requests

4. OPEN SOURCE
• Dual licensed
• MIT
• GPLv2

5. STORE
• Persistent client-side storage
• Cross-browser
• IE 5+, Firefox 2+, Safari 4+, Chrome, Opera 10.5+
• iPhone 2+, Android 2+
• localStorage, sessionStorage, globalStorage, userData

6. STORE
• Falls back to in-memory storage
• Never worry about whether a persistent store exists
• Support for time-based expiration of data
• Extensible

7. STORE API
• store a value
• amplify.store( key, value )
• get a value
• amplify.store( key )
• amplify.store() // all values

8. STORE API
• expiration
• amplify.store( key, value, { expires: 1000 } )
• specific store
• amplify.store.sessionStorage( key, value )
• amplify.store.sessionStorage( key )

9. REQUEST
• abstraction for requesting data
• separates requesting data from:
• retrieving data
• parsing data
• caching data

10. REQUEST API
• define a request
• amplify.request.define( resourceId, resourceType, settings )
• make a request
• amplify.request( resourceId, data, callback )

11. REQUEST API
amplify.request.define( “my-data”, “ajax”, {
url: “/path/to/resource”,
dataType: “json”
});

12. REQUEST API
amplify.request( “my-data”, { foo: “bar”, baz: “qux” },
function( data ) {
// do something awesome with data
});

13. REQUEST API
amplify.request({
resourceId: “my-data”,
data: { foo: “bar”, baz: “qux” },
success: function( data ) {},
error: function( data ) {},
});

14. REQUEST TYPES
• ajax
• custom one-off requests
• more to come
• easy to define new request types

15. REQUEST API
amplify.request.define( “echo”, function( settings ) {
settings.success( settings.data );
// success, error, data, resourceId
});

16. MOCKING REQUESTS
• real request
• amplify.request.define( “my-data”, “ajax”, ... )
• mock request
• amplify.request.define( “my-data”, function( settings ) { ... } )

17. MANIPULATING DATA
• change the data format from third party services
• change the status (success/error) of a request
• many services always respond with a 200 OK HTTP status

18. REQUEST DECODERS
• allowyou to parse data before calling the success or error
callback
• change the data passed to the callback
• change the status of the request

19. REQUEST DECODERS
amplify.request.define( “my-data”, “ajax”, {
url: “/path/to/resource”,
dataType: “json”,
decoder: function( data, status, xhr, success, error ) {
if ( data.errCode ) {
error({ code: data.errCode, msg: data.errMsg });
} else {
success( data );
}
});

20. REQUEST CACHING
• boolean: in-memory
• number: in-memory with expiration (in ms)
• “persist”: delegate to amplify.store()
• “sessionStorage”: delegate to amplify.store.sessionStorage()
• easy to create new cache types

21. PUB/SUB
• not on initial list of features
• we usually use custom events in jQuery
• needed a simple system to post messages for amplify.request

22. PUB/SUB API
• subscribe to a message
• amplify.subscribe( topic, callback )
• amplify.subscribe( topic, context, callback )
• amplify.subscribe( topic, callback, priority )
• amplify.subscribe( topic, context, callback, priority )

23. PUB/SUB API
• publish a message
• amplify.publish( topic )
• amplify.publish( topic, arg1, arg2 )
• returns boolean indicating whether any subscription returned
false

24. REQUEST MESSAGES
• request.before, request.before.ajax
• do something before a request
• prevent a request
• request.success, request.error, request.complete
• do something after a request

25. AMPLIFY LINKS
• http://github.com/appendto/amplify
• http://amplifyjs.com
• http://groups.google.com/group/amplifyjs
• http://swarm.amplifyjs.com/user/amplify
• irc://freenode/amplify.js