Introducing Dan Gebhardt @dgeb Boston Ember January 2014

A STORY THAT BEGINS AND ENDS WITH EMBER

2+ YEARS AGO

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WHAT'S NEXT FOR AMBITIOUS WEB APPLICATIONS?

ASYNCHRONOUS UI

OFFLINE SUPPORT

DATA SYNCHRONIZATION

EDITING CONTEXTS

UNDO / REDO

NEW CHALLENGES FOR DATA

DATA CHANGES OVER TIME

SAME DATA - MANY PLACES

SAME DATA - MANY STATES

SOURCE OF TRUTH ?

AD HOC CONNECTIONS

TEMPORARY CONNECTIONS

BLOCKING OPERATIONS

NON-BLOCKING CONNECTIONS

CONFLICT RESOLUTION

PRIMITIVE SOLUTIONS

COMMON INTERFACES

DATA NORMALIZATION

TRANSFORMATIONS

EVENTS

PROMISES

BLOCKING TRANSFORMATIONS

NON-BLOCKING TRANSFORMATIONS

JUNE 2013

7 MONTHS LATER ...

A standalone library for coordinating access to data sources and keeping their contents synchronized.

• Plain JavaScript • No dependencies (excepts a Promises/A+ library like RSVP) • Supports access to and transformation of any number of data sources... as long as they support the right interfaces. • Supports synchronous and asynchronous operations • Supports blocking and non-blocking operations

COMMON INTERFACES

• Requestable - for accessing and modifying data • Methods: find, add, update, patch, remove, link, unlink • Transformable - for transforming data • Methods: transform COMMON INTERFACES

• MemorySource - an in-memory store • LocalStorageSource - an in-memory store that also persists to local storage • JSONAPISource - for JSON-API-compliant REST requests CORE SOURCES

TRANSFORMATIONS

{"op":"remove","path":["planet","1389295329110.3"]} {"op":"add","path":["planet","1389295895882.1"],"value": {"name":"Mercury","id":"1389295895882.1"}} {"op":"remove","path":["planet","1389295895882.1"]} {"op":"add","path":["planet","1389296188090.2"],"value": {"name":"Mercury","id":"1389296188090.2"}} {"op":"add","path":["planet","1389296196274.3"],"value": {"name":"Venus","id":"1389296196274.3"}} {"op":"add","path":["planet","1389296197897.4"],"value": {"name":"Earth","id":"1389296197897.4"}} {"op":"add","path":["planet","1389296199041.5"],"value": {"name":"Mars","id":"1389296199041.5"}} TRANSFORMATIONS Transformations follow RFC 6902 (JSON Patch):

• Document is a complete implementation of RFC 6902 • Transformation methods: transform, add, remove, replace, move, copy and test. • Retrieval methods: retrieve TRANSFORMATIONS

EVENTS

• Notifiers can emit messages to an array of subscribed listeners. • Evented interface can emit events and listen for responses. • Promises returned as responses can be resolved (first to resolve) or settled (once all resolved or failed). EVENTS

BLOCKING TRANSFORMATIONS

NON-BLOCKING TRANSFORMATIONS

• TransformConnector for connecting a source and target. • Two connectors are needed for bi-directional syncs. • Connectors can be blocking or not • RequestConnector for coordinating requests to data CONNECTORS

DEMO TIME!

+ ?

• Ember Data Orbit Adapter • Keep Orbit in the adapter layer • Works ok, but doesn't allow for bi-directional syncs INTEGRATION OPTIONS

• Ember Data Support for Orbit Interfaces • Would provide the benefits of Orbit to Ember Data users • Would involve some breaking changes • Require use of Orbit-compliant adapters INTEGRATION OPTIONS

• Ember/Orbit Integration without Ember Data • Would allow for the most flexibility in implementation • Would add one more option to a crowded field INTEGRATION OPTIONS

SOURCES • Igor Terzic's Ember Data talk: http://www.infoq.com/presentations/ember-data • Alex Maccaw's post on Asynchronous UIs: http://blog.alexmaccaw.com/asynchronous-ui • Differential synchronization by Neil Fraser: https://neil.fraser.name/writing/sync/ • Promises A+ http://promises-aplus.github.io/promises-spec/

AND FINALLY... • Orbit.js: https://github.com/cerebris/orbit.js • Orbit / Ember example: https://github.com/dgeb/orbit-ember-example • Slides: https://speakerdeck.com/dgeb

Boston Ember January 2014 THANKS! @dgeb