Engineering JavaScript
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The document is a presentation by Dr. Jim Purbrick, a technical director at Linden Lab, discussing engineering practices in JavaScript, particularly the module pattern and concepts like inheritance and dependency injection. It also highlights the scale of operations at Linden Lab, including their significant use of computing resources and software development approaches. Additional resources and references for further reading are provided at the end.
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Engineering JavaScript
- 1. Engineering JavaScript Dr Jim Purbrick Async 10th March 2011
- 2. Who Am I? Technical Director at Linden Lab Setup Linden Lab Brighton Software Engineer Musician Freelancer Entrepreneur
- 3. That’s No Moon... 35,000 CPU Cores Weekly Releases No Downtime 1.5 MLOC 100 Engineers 10 Years Image: jurvetson C++, Python, Perl, PHP, C#...
- 4. 21st Century JavaScript Image: Google Image: W3C
- 5. Module myOrg = (function(myOrg) { var myApp = myOrg.myApp = myOrg.myApp || {}; function myPrivateFunction() { // Do my thing. } myApp.myPublicFunction = function() { return myPrivateFunction(); } return myOrg; }(myOrg || {}));
- 6. myOrg = (function(myOrg) { Class var myApp = myOrg.myApp = myOrg.myApp || {}, myClass = myOrg.myApp.myClass = myOrg.myApp.myClass || {}; myClass.create = function() { var that = {}; myPrivateMethod() { } that.myPublicMethod = function() { myPrivateMethod(); }; return that; }; return myOrg; }(myOrg || {}));
- 7. Inheritance myOrg = (function(myOrg) { var myApp = myOrg.myApp = myOrg.myApp || {}, mySub = myOrg.myApp.mySub = myOrg.myApp.mySub || {}; mySub.create = function() { var that = myApp.myClass.create(), myClassMyPublicMethod = that.myPublicMethod; that.myPublicMethod = function() { // Do something. return myClassMyPublicMethod(); }; return that; }; return myOrg; }(myOrg || {}));
- 8. Dependency Injection myOrg = (function(myOrg) { var myApp = myOrg.myApp = myOrg.myApp || {}, mySub = myOrg.myApp.mySub = myOrg.myApp.mySub || {}; mySub.create = function(params) { var that = params.constructor(), myClassMyPublicMethod = that.myPublicMethod, $ = params.jQuery; that.myPublicMethod = function() { return myClassMyPublicMethod(); }; return that; }; return myOrg; }(myOrg || {}));
- 9. Production <script type="text/javascript"> $(window).load(function() { var params, mySubInstance; params = { constructor: myOrg.myClass.create, jQuery: jQuery }; mySubInstance = myOrg.myApp.mySub.create(params); // Do something with mySubClassInstance. }; </script>
- 10. Test JsHamcrest.Integration.QUnit(); JsMockito.Integration.QUnit(); test('mySubClass calls super class constructor', function () { var params, mySubInstance; params = { constructor: mockFunction(), jQuery: mockFunction() }; mySubInstance = myOrg.myApp.mySub.create(params); verify(params.constructor, once())(); });
- 11. More? 1. http://www.adequatelygood.com/2010/3/ JavaScript-Module-Pattern-In-Depth 2. http://www.crockford.com/ 3. http://oreilly.com/catalog/9780596517748 4. http://docs.jquery.com/Qunit 5. http://jsmockito.org/