Performance, Games, and Distributed Testing in JavaScript

This document summarizes Nicholas C. Zakas' presentation on high performance JavaScript. It discusses how the browser UI thread handles both UI updates and JavaScript execution sequentially. Long running JavaScript can cause unresponsive UIs. Techniques to ensure responsive UIs include limiting JavaScript execution time, using timers or web workers to break up processing, reducing repaints and reflows, and grouping style changes. Hardware acceleration and optimizing JavaScript engines have improved performance but responsive UIs still require discipline.

20100807 OSC Nagoya での講演資料 # スライドのみで見やすいよう若干整理 P5〜 Agenda P17〜 "HTML5" って何？ P56〜 HTML5 の範囲は？ P67〜 ブラウザのサポートは？ P94〜 IE6 はどうするの？ P118〜 使用上の注意 P147〜 便利なツールは？ P152〜 One Point Q&A P186〜 追加資料

The document discusses techniques for optimizing JavaScript and AJAX performance. It recommends planning for performance from the start, measuring performance during development, reducing unnecessary code, optimizing assets, and handling long-running processes by breaking work into chunks. Specific tips include minimizing HTTP requests, leveraging caching, optimizing regular expressions, and using innerHTML for document modifications instead of DOM methods.

This document discusses using JavaScript libraries to write unobtrusive scripts. It begins with a brief history of JavaScript development and introduces concepts like unobtrusive scripting and progressive enhancement. It then provides examples of basic unobtrusive scripts and discusses challenges like cross-browser event handling. The bulk of the document focuses on JavaScript libraries and their benefits, listing common library features and some of the most popular libraries like jQuery. It concludes with a specific example using Yahoo's YUI library to add AJAX functionality to a login form.

This document summarizes a presentation about using the Siesta testing framework for unit and functional testing of JavaScript code. The presentation covers the benefits of Siesta, how to write unit tests, how to do functional testing by simulating user interactions, querying components, and new features of Siesta like an improved UI, auto-scrolling, and code coverage. It also provides examples of unit tests for a user model class and discusses testing views by testing components in isolation and their public API.

In the beginning, progressive enhancement was simple: HTML layered with CSS layered with JavaScript. That worked fine when there were two browsers, but in today's world of multiple devices and multiple browsers, it's time for a progressive enhancement reboot. At the core is the understanding that the web is not print - the same rules don't apply. As developers and consumers we've been fooled into thinking about print paradigms for too long. In this talk, you'll learn just how different the web is and how the evolution of progressive enhancement can lead to better user experiences as well as happier developers and users.

From the 'HTML5 player showcase/How to Build an HTML5 player' given at the Open Video Conference in October 2010.

1) Web app performance can be improved through code splitting techniques that divide JavaScript bundles into smaller chunks to reduce loading time. 2) Compiler optimizations like tree shaking, constant folding, and dead code elimination can help reduce code size and evaluation time by removing unused code. 3) Code splitting libraries like Webpack allow splitting code at the module or route level to preload important chunks and lazily load others on demand to improve performance.

HTML 5 is the latest version of the HTML standard. It includes several new elements and features to improve structure and behavior. Some key changes include new semantic elements like <article>, <aside>, <header>, and <footer>; built-in support for audio and video; the <canvas> element for drawing graphics; and forms with new input types. HTML 5 aims to simplify HTML and separate structure and presentation, making code cleaner and pages more accessible. It is developed jointly by the WHATWG and W3C organizations.

Introductory overview of testing techniques for web application development. Explains where different testing methods fit in to the software development cycle.

From Streaming Media West Conference Huntington Beach, CA November 2013 C202: HOW TO: Making the HTML5 Video Element Interactive The HTML5 Video element has now become widely used by browsers and supported in a broad set of websites for streaming video content. With some JavaScript and CSS, we can leverage the HTML video element to create highly interactive experiences for the viewer in both traditional and mobile browsing environments. This hands-on session explores the integration of events with the video timeline, creating positioned hotspots with links and dynamic content, and capturing user input. In addition, the session examines supporting mobile platform browsers along with future opportunities with the HTML5 video tag. Get sample code, ideas, and best practices for making the HTML5 video element an engaging interactive experience for your viewers. Speaker: Chuck Hudson, Co-Author, HTML5 Developer's Cookbook

The document discusses various techniques for improving front-end website performance, including reducing the number of HTTP requests, using content delivery networks and caching, gzip compression, optimizing CSS and JavaScript loading, image optimization, and lazy loading of content not visible initially. Specific techniques mentioned include combining files, setting long cache expiration headers, minifying files, parallelizing downloads, and deferring non-critical JavaScript initialization. The goal is to render an initial version as fast as possible through optimizations that reduce page load time.

An intro to nightwatch(a tool to create and run functional tests, e2e tests using selenium in the background) and examples of cases, also how to integrate nightwatch to a Continous Integration tool

This document discusses jQuery UI and plugins. It provides an overview of jQuery UI classes that can be used to style elements. It also demonstrates several common jQuery UI widgets like buttons, accordions, dialogs, and tabs. The document discusses jQuery UI effects for animations and transitions. It provides tips for identifying good plugins based on aspects like their API, documentation, support, and community. Overall, the document is an introduction to using jQuery UI and evaluating jQuery plugins.

This document discusses optimizing Meetup's performance by reducing page load times. It recommends reducing JavaScript, image, DOM, and CSS files. Specific techniques include externalizing and concatenating JavaScript, lazy loading images and scripts, minimizing DOM elements, writing efficient CSS selectors, and profiling code to optimize loops and DOM manipulation. Reducing page weight through these techniques can improve the user experience by speeding up load times and drop in member activity.

80% of the time it takes for a web page to load is on the client side. Using all the tips in this presentation should cut 25% to 50% off the load time of optimized page requests. Drupal (6 or 7) can be used to, fairly easily, implement a whole bunch of these “front-end performance” upgrades, and knock a ton of errors off of the Yahoo! and Google speed-checker tools validation checklists.Get firebug first.

This document discusses the importance of unit testing JavaScript code. It provides reasons for testing JavaScript, such as avoiding bugs when refactoring code or introducing errors. The document discusses how to write testable JavaScript by separating business logic from views. It also recommends choosing JavaScript unit testing tools like Jasmine and Siesta, and integrating tests into continuous integration processes to run automatically on commits. Functional testing tools like Selenium are also mentioned for testing user interactions across browsers.

The document discusses the origins and development of JSON (JavaScript Object Notation). It describes how Douglas Crockford discovered JSON in 2001 and published the first JSON specification in 2002. It outlines some of the key events in the early adoption of JSON, including its use for browser/server communication and as an alternative to XML.

- The original vision of the World Wide Web was as a hyperlinked document retrieval system, not for presentation, sessions, or interactivity. If it had stayed true to this vision, modern sites like Yahoo would not exist. - Browser wars in the 1990s led to proprietary technologies that frustrated developers. The introduction of JavaScript in 1995 allowed for dynamic and interactive web pages. - By the 2000s, Microsoft's Internet Explorer dominated the browser market, bringing some stability through standards like DOM and DHTML. However, cross-browser differences still posed challenges for developers.

The document discusses optimizing performance for Ajax applications. It recommends: - Keeping client-side code light by only requesting necessary data from the server via JSON messages. - Avoiding unnecessary DOM touches and reflows which are computationally expensive. - Measuring performance before and after optimizations to validate improvements rather than relying on intuition. - Optimizing algorithms and avoiding unnecessary work rather than prematurely optimizing without evidence of need.

Computer programs are the most complicated things that humans make. They must be perfect, which is hard for us because humans are not perfect. Programming is thought to be a “head” activity, but there is a lot of “gut” involved. Indeed, it may be the gut that gives us the insight necessary for solving hard problems. But gut messes us up when it come to matters of style. The systems in our brains that make us vulnerable to advertising and propaganda also influence our programming styles. This talk looks systematically at the development of a programming style that specifically improves the reliability of programs. The examples are given in JavaScript, a language with an uncommonly large number of bad parts, but the principles are applicable to all programming languages.

This document summarizes upcoming improvements and new features in web browsers, including Firefox 3.1, Safari 4, Internet Explorer 8, Opera 10, and Google Chrome. Many of the browsers are focusing on better JavaScript performance through new engines like TraceMonkey and V8. New features include process per tab, postMessage for cross-domain communication, HTML5 drag and drop, and the Canvas element for offloading rendering to the client. Overall the browsers are aiming to improve speed, compatibility, and the user experience through these new features and technologies.

<p>Security design is an important, but often neglected, component of system design. In this session, Douglas Crockford, creator of Javascript Object Notation, will outline the security issues that must be considered in the architecture of Ajax applications.</p> <p>The design of the browser did not anticipate the needs of multiparty applications. The browser’s security model frustrates useful activities and allows some very dangerous activities. This talk will look at the small set of options before us that will determine the future of the Web.<br /> During this session, attendees will:</p> <ul> <li>Learn why effective security is an inherent feature of good design;</li> <li>Experience a real-time demo of a Ajax client/server system based on sound security principles</li> <li>See how to apply secure design to rich web applications.</li> </ul>

JSON is a lightweight data-interchange format that is easy for humans to read and write and for machines to parse and generate. It is built on two structures: a collection of name/value pairs and an ordered list of values. JSON is widely used to transmit data between a server and web application, and has largely become the default format for asynchronous browser/server communication. While easy for machines to parse and generate, it is also readable by humans.

This document discusses object-oriented programming concepts in JavaScript, including encapsulation, inheritance, and polymorphism. It provides examples of implementing encapsulation with private and public properties and methods. Inheritance is demonstrated through extending classes. Polymorphism is shown through functions that can take on different meanings based on context. JSON and closures are also mentioned.

The document discusses different approaches to object-oriented programming in JavaScript, including classical and prototypal inheritance, constructor functions, and the prototype property. It explains how prototypal inheritance works by linking objects together through their internal prototype properties. Constructor functions and the new operator allow simulating classical inheritance by establishing prototype links. Various design patterns are also covered, such as public/privileged methods, singletons, modules, and parasitic inheritance.

Topics covered: Closure, Callback, Module Pattern, Cascading, Curry, Inheritance, Pseudo Classical, Prototype

\n\nThe document discusses scalable JavaScript application architecture. It advocates for a modular approach where each component (module) has a limited, well-defined purpose and interface. Modules are loosely coupled by communicating through a central sandbox interface rather than directly referencing each other. The core application manages modules by registering, starting, and stopping them. It also handles errors and enables extension points. This architecture aims to build flexible, maintainable applications that can evolve over time.

The document discusses the messy and buggy state of the DOM across browsers and strategies for writing cross-browser JavaScript code. It notes that nearly every DOM method has bugs or inconsistencies in some browsers. It then covers strategies like feature detection, graceful fallback for missing features, simulating features via workarounds, monitoring for regressions, and having a robust test suite to prevent regressions in one's own code. The overall message is that the DOM is messy and one needs to "know your enemies" by thoroughly testing code in all target browsers.

The document discusses the benefits of exercise for both physical and mental health. Regular exercise can improve cardiovascular health, reduce stress and anxiety, boost mood, and enhance cognitive function. Staying physically active for at least 30 minutes each day is recommended for significant health benefits.

Nicholas C. Zakas discusses common JavaScript performance issues and recommendations to address them. He covers scope management, data access, loops, and DOM manipulation. The key points are to minimize scope chain lookups, store frequently accessed data in local variables, optimize loops, avoid reflows from DOM changes, and leverage modern browser optimizations. Overall, the talk provides practical tips to speed up JavaScript code by addressing issues related to scope, data access patterns, loops, and DOM interactions.

This document summarizes upcoming improvements and new features in web browsers, including Firefox 3.1, Safari 4, Internet Explorer 8, Opera 10, and Google Chrome. Many of the browsers are focusing on better JavaScript performance through new engines like TraceMonkey and V8. New features include process per tab, postMessage for cross-domain communication, HTML5 drag and drop, and the Canvas element for offloading graphics work to the client. Overall the browsers are aiming to improve speed, compatibility, and the user experience through these new implementations and technologies.

This document summarizes jQuery, a JavaScript library, and its features. It discusses jQuery's selector engine, DOM manipulation abilities, and browser compatibility sniffing. It also describes jQuery UI, a plugin library that adds interactive UI elements like drag and drop. The document outlines jQuery's large plugin ecosystem and testing framework. It concludes with information on profiling jQuery applications for performance optimization.

- The document is a presentation on Ajax given by Alex Russell that covers what Ajax is, how it works, when it should and should not be used, tools for Ajax development, debugging techniques, and the future of Ajax and the open web. - It includes examples of building an auto-save feature with Ajax using plain JavaScript, Prototype, and Dojo and discusses language features of JavaScript. - The presentation aims to provide enough knowledge and code examples to get started with Ajax development while addressing open web standards and browser compatibility.

The document discusses unit testing and mocking frameworks. It begins with an introduction to unit testing principles and describes arranging, acting, and asserting tests. It then demonstrates creating a simple test using test-driven development. The document advocates for using "stunt doubles" like fakes, stubs and mocks to isolate tests from external dependencies. It provides examples of using the Moq mocking framework to define expectations and verify behavior. Key recommendations include writing loosely-coupled code and using a mocking framework to define helpers and expectations for each test.

The document discusses performance improvements in upcoming browsers. It covers new browsers like Firefox 3.1, Safari 4, Internet Explorer 8, Opera 10, and Google Chrome. These browsers will have better JavaScript engines and take advantage of new technologies like process per tab, native JSON support, and the canvas element to improve performance. Many JavaScript and CSS techniques are also described that can enhance performance by offloading work to the browser instead of through JavaScript libraries.

This document discusses iPhone development for experienced web developers. It begins with an introduction and poll questions. The main differences from web development are then outlined, such as slower processors, latency considerations, and Objective C. Tools like Xcode and Cocoa are also introduced. The presenters then discuss their project, which uses RESTful web services and JSON. Code examples and concepts like MVC are provided. Memory management, testing, and distribution challenges are also covered. In the end, the presenters discuss what they like and don't like about iPhone development.

Presentation about the features of JavaFX. See how to use video, different deployment types, JavaScript integration, annimations and more. Demo's not included.