1 / 11

jQuery Refactoring how we think about client-side scripting

This article explores the foundations and evolution of jQuery, a powerful JavaScript library that revolutionized client-side scripting. We delve into its origins, addressing problems inherent in JavaScript, such as cross-browser inconsistencies and the complexities of object/event handling. Created by John Resig in 2006, jQuery streamlines DOM manipulation, event handling, and AJAX requests, making it accessible for web developers. Its unobtrusive design and extensive plugin ecosystem contribute to its widespread adoption and enduring relevance in modern web development.

dreama
Download Presentation

jQuery Refactoring how we think about client-side scripting

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. jQueryRefactoring how we think about client-side scripting Andrew Roazen Cline Library Technology Services February 8, 2011

  2. What is jQuery? • A library providing a superset of JavaScript • An extensible, pluggable platform • A way ofmore intuitively programming the Web

  3. Foundations of jQuery JavaScript (Brendan Eich, 1995) • Inspired by HyperCard’s interactivity and Java’s object-oriented features • Designed as “Java Lite” with a minimum of bloat and a shallow learning curve for Java/C programmers • Quickly cloned by MS: extended, embraced… but not extinguished

  4. Foundations of jQuery Problems with JavaScript • Incompatibility: No vendor consensus on implementation of object/event referencing, object positioning or even event capturing • CSS still a draft concept • Target audience largely not Java/C programmers • Massive reinvention of wheel to perform simple tasks

  5. Foundations of jQuery Cross-browser libraries (early 2000s) • Simple wrapper functions which replace incompatible native object referencing/event capturing functionality • The beginnings of effects libraries built on these wrapper functions (script.aculo.us, MooTools) • Libraries became larger and more complex but not proportionately mature • A tendency to focus on user experience rather than the broader underlying issue behind it: a low level language meant to solve a platform-specific task

  6. Foundations of jQuery CSS behaviors (IE-only, early 2000s) • Introduced the ability to attach function-based behaviors to classes rather than named objects • Benefits of prototyping without the overhead • Not part of any recognized standard • No adoption outside IE

  7. Enter jQuery jQuery(John Resig, 2006) • Inspired by: • IE’s CSS behaviors • CSS selector syntax • XLST (Xpath)selector syntax

  8. Enter jQuery jQuery(John Resig, 2006) • Selectors: object abstraction by Xpath-like queries describing/combining class, ID, tag, node relationship, attribute values, etc. • Code written as chainable methods applied to selector queries, making code compact and intent more concrete • Utility functions for the most common interactive content development tasks: • Xpath-flavored DOM node traversal / manipulation • Event handling, from simple capturing to complex delegation/queuing • Form control /control status selectors • Basic CSS effects/animation • AJAX / JSON / XML • .data() method for storing/querying arbitrary data structures in an element

  9. Enter jQuery jQuery(John Resig, 2006) • Unobtrusive JavaScript: script never appears inside <HTML>, separating content and controller • Nonbloated: Base library only 29K minified/gzipped, 207k uncompressed • Extensive plugins libraries as simple or complex as your needs • jQuery UI for the more sophisticated widgets / effects • MIT/GPL2 license • Bundled into a growing number of sites and commercial/open source products • CDN hosted by Google, Microsoft as well as jquery.com itself

  10. Enter jQuery jQuery(John Resig, 2006) • Mature: • consistently fine tuned for speed and stability (leveraging native platform strengths where possible) • resisting explosive or trendy feature creep • stewarded by a large enough user/developer base to make it unlikely to become abandonware • Aggressively cross-browser compatible, standards compliant and adaptive to trends in web technologies

  11. Example JavaScript: jQuery: $("select.swaptext").change (function() { varannot=$(this).closest('form').find('.note'); $(annot).find('div').hide(); $('#'+$(annot).attr('id')+$(this).val()).show(); }); <select class=”swaptext”> function newswap (target) { for (vari in this) { myobj = document.getElementById(this[i]);if (i != 'swapit') {myobj.style.display = 'none';} } document.getElementById (this[target]).style.display = 'block'; } Array.prototype.swapit= newswap; <select id="srchtype" onchange="swapsrch.swapit(this.options[this.selectedIndex].text);">

More Related