wave presentation

Google Wave

Monday, August 31, 2009

© 2007 William J. EdneyLast updated 20090824

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Google Wave Hackfest STLWilliam J. Edney

[email protected]

A Quick OverviewGoogle Wave for Developers


What is Wave?

Email re-imagined A unification of email, IM, blogs

and wikis A new collaborative platform


But wait… there’s more…


But wait… there’s more…A lot more for developers…

A real platform



A real platform Client



A real platform Client Server



A real platform Client Server

Protocols (several, in fact)


Terminology


A Wave What the user sees in

the ‘email-like’ Web client A threaded discussion

A logical grouping of wavelets


A Wavelet A container for 1..n blips Can have 1..n participants

Entity that is hosted Manages access control


A Blip A single message

Uses a Document to hold content Blips can be nested in other blips Uses Annotations to hold metadata


A Document Holds the content of a blip


An Annotation Holds metadata, like formatting

Unlike HTML, formatting information is not embedded in a

Wave Document


A Participant An entity that can create or edit

waves Can be a human

Can be a robot (agent)


Architecture


Multi-client / single-server



GWT protocol



GWT protocol

Google protobuf



GWT protocol

Google protobuf Google protobuf



GWT protocol

Google protobuf Google protobuf

JSON-RPC


Multi-client / multi-server


Multi-client / multi-server

Wave Federation

Protocol (XMPP-based)


OperationalTransformation


Wave is a multi-user, real-time environment

How do we keep things in sync?


Changes to a document can be modeled as operations

Operations can be transformed into other operations

Operations can be composed (condensed) into other operations


Operations Example

Skip 8

ElementStarttagName: “li”

Insert“hello”

ElementEnd


Operations are how changes are modeled

Operations can be transformed into other operations

Operations can be composed (condensed) into other operations


Concurrency (naive)Concurrency (the naive way)


Concurrency (correct)Concurrency (the correct way)


Editors do not produce HTML Editors extract operations against documents and store ‘metadata’ like

formatting in annotations Editors perform operations against

documents and, using formatting metadata in annotations, produce the

visible result


API


Embed API Embed the Wave ‘editor’ GUI into a

web page

loadWave(waveId:String,opt_loadCallback:Function)

addParticipant()

addReply()


Embed API tips For now, you must be logged in to Wave in order to view a Wave on a

web page The Wave ID can only be

determined from the full client -see the “Debug” menu

The Wave being viewed must have the ‘[email protected]’ user added


Gadget API Write Wave gadgets to use inside of

a Wave Similar to writing a Google Gadget

setStateCallback(callback:Function,opt_context:Object)

setParticipantCallback(callback:Function,opt_context:Object)

wave.getState()submitDelta(delta:Object)


Gadget API tips/caveats If you want to know when your

gadget is loaded, register an ‘onload’ handler

The full OpenSocial API isn’t supported, but its coming

The security model is still being worked out - submitDelta() has no

restrictions.


Robot (Agent) APIWrite your own ‘automated

participant’ for the Wave system Two supported languages: Java and

Python Runs on Google App Engine Has full access to a wave - its

wavelets, blips, etc.


Robot (Agent) API tips/caveats Only runs on Google App Engine for

now Think ‘events’ - wave events

received from the wave:Wavelet Created/Removed

Participants ChangedBlip Deleted/Submitted

Document Changed


Robot (Agent) API tips/caveats If you’re writing in Java, you need to manually create your capabilities.xml

file Don’t forget to include the Wave

client libraries as part of your project!


Conclusion


Thank you!

Email: [email protected]


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