Masterin Large Scale Java Script Applications
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The document discusses strategies for mastering large-scale JavaScript applications, highlighting the challenges of managing complexity and performance while utilizing frameworks like qooxdoo. Key topics include the importance of good abstractions, tooling for development, and techniques for optimizing startup time and widget creation. Additionally, it emphasizes the need for internationalization and clean code practices in web development.
![On Demand Code
• Code
qx.io.PartLoader.require("settings", function()
{
mailclient.ui.SettingsDialog.getInstance().open();
}, this);
• Content
...
"packages" : {
"parts" : {
"settings": {
"include" : ["mailclient.ui.SettingsDialog"]
}
}
}
...](https://image.slidesharecdn.com/masterinlargescalejavascriptapplications-090918083625-phpapp02/85/Masterin-Large-Scale-Java-Script-Applications-44-320.jpg)
Masterin Large Scale Java Script Applications
- 1. Mastering Large Scale JavaScript Applications Fabian Jakobs
- 2. About • Senior JavaScript Developer at 1&1 • core developer since 2006 @fjakobs
- 3. Man With Two Hats
- 4. Framework Application
- 10. JavaScript Application • Single Page Application • Client Logic in JavaScript • Client-Server Communication with AJAX calls
- 11. Large Scale • Complexity and Size of JavaScript code • ~ 150,000 LOC • ~ 1000 Classes
- 13. • Rich Web Mail Application • Pure JavaScript Client • Backend Communication with Ajax calls • Based on qooxdoo
- 14. • Client-side JavaScript Framework • Cross-browser web applications • Open Source
- 15. JavaScript isn‘t made for this
- 16. JavaScript isn‘t made for this • No package mechanism • By default everything is in the global namespace • Only basic building blocks for OOP • Tooling still sucks
- 17. Everybody puts a layer on top • GWT covers JavaScript with Java • Cappuchino uses Objective-J • Adobe invented ActionScript • Everyone else uses (different) meta object systems written in JavaScript
- 18. qooxdoo OOP qx.Class.define("demo.Person", { extend : qx.core.Object, construct : function(firstName, lastName) { this.base(arguments); this._firstName = firstName; this._lastName = lastName; }, members : { getFullName : function() { return this._firstName + " " + this._lastName; } } });
- 19. Tooling
- 20. Tooling API Doc Unit Testing Linker Auto Completion Code Coverage Lint IDE Support
- 21. Tooling dilemma • Different OOP syntax makes generic tooling hard • Tools often depend in certain Framework features • Don‘t just look at the widgets, look at the development tools as well
- 22. Find the Right Level of Abstraction
- 23. Desktop Like Web Applications Need Desktop Abstractions • Widgets • DOM Nodes • Layout Manager vs • CSS • Themes • Browser Bugs
- 24. Abstractions Application Application Components Custom Widgets Base Widgets Framework UI Core (Rendering Engine) BOM (Cross Browser Code) Core (JavaScript OOP)
- 25. Desktop Style Development Model // Create a button var button = new qx.ui.form.Button("First Button", "demo/browser.png"); // Add button to container at fixed coordinates container.add(button, {left: 100, top: 50}); // Add an event listener button.addListener("execute", function(e) { alert("Hello World!"); });
- 26. Leaky Abstractions • Emulated behavior may be slower • e.g. Canvas wrapper for IE • For advanced tasks its essential to know the lower layers • CSS, HMTL, DOM knowledge is still needed
- 27. Styling
- 28. Styling No OS clone! No default theme Everything Custom!
- 31. i18n
- 32. i18n
- 33. i18n
- 34. i18n in qooxdoo this button = var qx.ui.form.Button(this.tr("Hello World!")); • Standards • gettext • CLDR • good external tooling • known by professional translators
- 35. Performance
- 36. Our Bottlenecks • Startup time • Widget creation • Table scroll performance
- 37. Startup Time The 3Cs + O • Combine • Compress • Cache • On demand
- 38. Combine • reduce number of requests • combine JS JS PNG PNG • JavaScript files • CSS JS PNG • Images
- 39. Compress • optipng et el for images • compress JavaScript • serve with gzip
- 41. Cache • Serve static files with „cache forever“ • Increase version number if content changes • Use Image servers
- 42. On Demand • Defer operations • Load Code on demand • Load Data on demand • Render UI on demand
- 43. On Demand Code • The initial view does not need • Editor • Settings • Address book • ...
- 44. On Demand Code • Code qx.io.PartLoader.require("settings", function() { mailclient.ui.SettingsDialog.getInstance().open(); }, this); • Content ... "packages" : { "parts" : { "settings": { "include" : ["mailclient.ui.SettingsDialog"] } } } ...
- 45. On Demand Data and UI • Thousands of mails in the inbox • Only load visible data • Only render visible rows of the table
- 46. Widget Creation • DOM operations are expensive • Creation Widgets is expensive • Reuse Widgets • Share Widgets • Pool Widgets • Increases Complexity!
- 47. Reuse Widgets pool and reuse share mail preview mail folder among tabs
- 48. Clean Code
- 50. Decouple UI Components Message Bus
- 51. Code Should be Executable in Isolation • Without rebuilding the application • Without restarting the application • Without a server
- 52. Unit Tests
- 54. Summary • Good Abstractions • Styling • Internationalization • Performance • Clean Code
- 55. colorstrip.gifT THE NEW ERA OF WEB DEVELOPMENT Thank you. Fabian Jakobs @fjakobs <[email protected]> http://qooxdoo.org
- 56. Fotos • http://www.flickr.com/photos/martin_uj/2505238011/ • http://www.flickr.com/photos/born-clothing/3764261653/ • http://www.flickr.com/photos/countrushmore/540548338/ • http://www.flickr.com/photos/gordonr/42555739/ • http://www.flickr.com/photos/evaekeblad/345203452/ • http://www.flickr.com/photos/oldonliner/1095360979/ • http://www.flickr.com/photos/imcomkorea/3496427357/ • http://www.flickr.com/photos/nhr/460382116/ • http://www.flickr.com/photos/evaekeblad/345203452/