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JavaScript and OSGi Simon Kaegi, Orion Project Co-lead IBM Canada @skaegi. What’s up with JavaScript …and why OSGi now?. 2005 – Open Source AJAX Libraries Firefox and Webkit 2008 – Google Chrome and … V8! WHATWG and HTML5 EcmaScript 5 (nee 3.1)
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JavaScript and OSGi Simon Kaegi, Orion Project Co-lead IBM Canada @skaegi
2005 – Open Source AJAX Libraries • Firefox and Webkit • 2008 – Google Chrome and … V8! • WHATWG and HTML5 • EcmaScript 5 (nee 3.1) • 2009 – Node.js
JavaScript 2013… • Aging AJAX Frameworks • Limited framework inter-op • Cottage industry of micro libraries • NPM Package Hell • (Tools are still horrible) • …victim of its own success
JavaScript is going through growing pains similar to what Java experienced ten years ago. • OSGi concepts and experiences are universal and relevant to JavaScript.
“OSGI seems like overengineered Java stuff. I'm generally pretty skeptical of big frameworks that do everything for everyone. Usually they're a bigpain.” • -Isaac Schlueter (emphasis is mine)
OSGi for JavaScript • Focused, Lightweight, Open • OSGi
Core JavaScript Problem Areas • Modularity • CommonJS “require” • AMD (Browser) – require(stringID, callback) – async • Node (Server) – require(stringID) – sync • ES6 Module Loader • http://wiki.ecmascript.org/doku.php?id=harmony:module_loaders • Closer to class-loading than bundle loading
Core JavaScript Problem Areas • Packages • NPM Packages • Closest thing to a bundle but more just project metadata • OSGi bundles can be NPM Packages and vice-versa • Useful work to be done right now!
Core JavaScript Problem Areas • Asynchronous API • Registered Callback Pattern (Node) • doService(params, callback) • Promises “A+” • doService(params).then(onSuccess, onFailure) • http://promises-aplus.github.com/promises-spec/ • W3C DomFutures • ES6 Generators / Co-routines • http://wiki.ecmascript.org/doku.php?id=harmony:generators
Core JavaScript Problem Areas • Extensibility and Services • OpenAjax / OpenSocial • Web Intents (W3C Webapps WG) • No strong standards plays at the moment • Go OSGi!
Orion and OSGi • MicroServices • Complete implementation of OSGi Services API • Uses Promises for return types to decouple from async service implementation details • Data only / No transferable functions • PluginRegistry • OSGi Lifecycle and Bundle State semantics used for Plugins • OSGi Framework startup • Preferences/Settings • Implementation of Configuration Admin and Metatype for Plugin Settings and Schema
Orion Core Retrospective • Orion core “strongly” OSGi influenced • Very small, fast, stable and predictable • Nearly all OSGi service specifications in the compendium are applicable in JavaScript. • Direct Service API use has poor usability characteristics • We need to find a simpler usage pattern to make OSGi Services more approachable to the JavaScript community.
Closing Thoughts • JavaScript is an increasingly reasonable choice as a systems language • Tons of innovation and tons of growing pains • OSGi can really be of help here however • We need to correct some invalid perceptions • We need to make our APIs easier to use and adopt