Java Script Framework

Introduction
In the following we list criteria to take into account when choosing a JavaScript Framework for a web application project and evaluate several frameworks according to these criteria.

It must be noted though, that the choice of a JavaScript framework must be even more project specific than the choice of a web development framework. In addition, the choice of a web framework may already determine the JavaScript framework (e.g. because one comes bundled). For these reasons, we also give some general considerations:


 * Will the application make use of other JavaScript libraries - e.g. googlemaps, etc.? If so, care must be taken to choose a framework that plays well with others.
 * Is a heavy-weight framework acceptable, or will light-weight options do?
 * Is security an issue? When sensitive data and ajax are to be used together, the framework should support secure XmlHttpRequests.
 * Is accessibility an issue?
 * How much and what kind of performance is needed? DOM traversals in large pages? Many event handlers attached to DOM nodes?
 * Do we want to host the JavaScript framework/library on our servers or include from a hosting service (or even a content delivery network)?

It is also quite common to switch JavaScript frameworks/libraries in the course of a project, because either special functionality (e.g. make tables sortable) is no longer sufficient or a framework which was used for faster prototyping becomes a performance bottleneck and is replaced with custom code. Since this approach is common, specialized JavaScript libraries providing just a single functionality should also be taken into consideration.

Method
The criteria are sorted by order of relevance in 3 categories:
 * A -> Must
 * B -> Should
 * C -> Nice to

Cat. A - Must

 * Opensource
 * Big community/support/Documentation
 * Cross Browser compatibility (which browsers?)

Cat. B - Should

 * Sufficient functionalities available
 * Sophisticated functionalities (for scientific use)
 * Fits to other JS Frameworks
 * Unique coding style
 * Supports CSS1-3
 * Easy to learn/adopt
 * Easy to reuse, to customize and maintain
 * Subversion or CVS version repository

Cat. C - Nice to

 * Plugins
 * Knowledge base (in house)

List of Frameworks
This list is not exhaustive, but it lists the most common frameworks.
 * Yahoo! User Interface Library
 * JQuery
 * Ext JS
 * Prototype
 * Scriptaculous
 * Dojo
 * MooTools
 * MochiKit

See more framework listings/comparisons here and here, in Wikipedia or just google.

Requirements collected from "eSciDoc Components/Behaviour"
Lists
 * Instant grid filter
 * Layer for input field/filter
 * Draggable corners (if cells contain more than they can display)
 * Client side sorting
 * Resizable columns

Input
 * Layers (open + close areas)
 * Auto Suggests

Menus


 * Highlighting

There is a need to indicate exactly where the mouse is pointing. The user must be kept from pointing to the wrong menu entry when clicking. Especially when the response will not be immediate, click targets are small or little contrast is given. The highlight can also indicate/enlarge a click target. A change in background colour or any another property is invoked (e.g. via CSS Pseudo-Classes). Usually the background of the element changes from dark to bright or vice versa. The highlight should not make the contrast worse or appear animated. It is also common to make the highlighted text underlined to indicate clickable targets.


 * Transition of Submenus

There are a lot of menu options and it has to be made clear where the submenu derives from. When a submenu is opened, it stretches from the main menu option to its final size, position or opacity. The movement must indicate from which direction the submenu arrives without imposing a noticeable delay to the user. The time should be less than 300ms.

> TBD some values should be provided concerning response time

Links

 * http://mootools.net/slickspeed/
 * a useful comparison
 * [[File:jquery.roundabout.min.txt]]