O slideshow foi denunciado.

Asynchronous Module Definition (AMD)

17

Compartilhar

Próximos SlideShares
Testing nodejs apps
Testing nodejs apps
Carregando em…3
×
1 de 18
1 de 18

Asynchronous Module Definition (AMD)

17

Compartilhar

AMD (Asynchronous Module Definition) is JavaScript's missing module system for the browser. It's a cosmos of interoperability, efficient loading, dependency resolution, code optimization, etc.

At excentos we're using it as part of the Dojo Toolkit to organize our single-page product advisor web apps.

I will give a short introduction to the concept and some tools and I'm going to explain why everyone with a reasonably-sized code base should adopt it.

AMD (Asynchronous Module Definition) is JavaScript's missing module system for the browser. It's a cosmos of interoperability, efficient loading, dependency resolution, code optimization, etc.

At excentos we're using it as part of the Dojo Toolkit to organize our single-page product advisor web apps.

I will give a short introduction to the concept and some tools and I'm going to explain why everyone with a reasonably-sized code base should adopt it.

Mais Conteúdo rRelacionado

Audiolivros relacionados

Gratuito durante 14 dias do Scribd

Ver tudo

Asynchronous Module Definition (AMD)

  1. 1. Asynchronous Module Definition (AMD) The missing client-side JavaScript module system.
  2. 2. about me Martin Stadler | Frontend engineer / JavaScript developer @ excentos | Web developer since 2004 (HTML/CSS, PHP, Python, Drupal, Plone, jQuery, …) | Developing modular single-page apps since 01/2010 | Email: martin@siarp.de | Twitter: @xMartin
  3. 3. excentos – what we do Product Advisors | Web apps to find the right product for you | Goal: to perform like a human sales expert | Single-page JavaScript, Dojo Toolkit
  4. 4. Overview Asynchronous Module Definition (AMD) | Motivation | Modules | Loading | Optimization | Conclusion | Questions/Discussion
  5. 5. Motivation | Pages turn into apps ● More code ● More complex ● Serious development, not just a few lines of script | Design principles ● Separate into reusable components ● Avoid global namespace pollution
  6. 6. What is a Module? Manual dependency resolution <head> <script src="myLib.js"></script> <script src="myLibPlugin.js"></script> <script src="mySpaghettiCode.js"></script> </head>
  7. 7. What is a Module? JavaScript module pattern var mymodule = (function() { var a = 'x', doSth = function(){...}; return { getA: function() { return doSth(a); } }; })(); Where does it live? | Global? At least reusable. | Closure? Closure of what?
  8. 8. What is a Module? | module = resource | declares dependencies Python mymodule.py app.py $ python app.py def printSth(): import mymodule sth print 'sth' mymodule.printSth() NodeJS mymodule.js app.js $ node app.js exports.printSth = var mymodule = sth function() { require('./mymodule'); console.log('sth'); }; mymodule.printSth();
  9. 9. What is a Module? AMD mymodule.js app.js index.html define(function() { define([ <script "mymodule" src="loader.js"></script> return { ], function(myMod) { <script> printSth: function() { require( alert("sth"); myMod.printSth(); ["app"], }; function(app) { }); // if app returned }); // something, we'd use // it here... }); </script>
  10. 10. AMD | Asynchronous ● Don't block browser ● Parallel download and interpretation ● Callbacks everywhere... | Loaded via script tag injection (not XHR + eval) ● Debugging ● X-Domain
  11. 11. Loader Plugins define([ "../Widget", "text!./tpl.html" ], function(Widget, tpl) { return new Widget({name: "mainApp", template: tpl}) }); | text! ● Load via XHR ● E.g. templates for widgets, data
  12. 12. Load non-modules require([ "dir/foo.js", "http://host/script.js" ], function(/*no return value*/) { // script.js has been loaded. });
  13. 13. Optimize! But aren't that too many HTTP requests? | Loading is very efficient ● Great for development ● Useful for a few or external resources | For production you need to make a build ● One big file or multiple layers ● Command line tools to resolve dependencies at build time (not run time) ● Inline text resources like template files ● Optimize (e.g. Closure Compiler)
  14. 14. AMD | Predecessors: ● Dojo: dojo.require("some.module") (resp. goog.require) ● LABjs: $LAB.script("some/module.js") ● CommonJS: require("some/module") | Current support ● jQuery 1.7 ● Dojo 1.7 ● MooTools 2.0 ● EmbedJS ● Backbone/underscore will
  15. 15. Tools | RequireJS ● Loader ● Optimizer (r.js) | curl.js | ... | Dojo 1.7 provides own AMD loader and build tool.
  16. 16. Resources | requirejs.org ● Great docs about AMD in general, too | github.com/amdjs ● Official spec in the wiki | Google group amd-implement | commonjs.org ● General information but not home of AMD any more
  17. 17. Conclusion | Should I use it? | How mature? | Will it stay?
  18. 18. danke! Martin Stadler | Email: martin@siarp.de | Twitter: @xMartin excentos GmbH www.excentos.com

×