meShowTransition

meShowTransition is a highly customizable script to enable CSS transitions on toggle of the display property.

Background

It is not possible to toggle the display property of an element (for instance from none to block) and apply transitions in one step. So many developers use opacity or similar properties to show/hide elements and be able to enhance user experience by applying fancy transitions.

But this leads to accessibility problems, because seemingly hidden elements are still available for screen-readers and can be focused by keyboard-navigation.

Usage

1. Include the JavaScript

Bundled & minified versions

meShowTransition depends on meTools.

It also uses Element.classList and Window.requestAnimationFrame, so you need to include a polyfill if you need to support IE9 (see http://caniuse.com/#feat=classlist and http://caniuse.com/#feat=requestanimationframe), which you can find at mePolyfills in the sources-folder.

• Either include all the dependencies yourself and include me-show-transition.min.js from the dist folder in your HTML page.
• or use one of the standalone bundles me-show-transition.bundle.min.js or me-show-transition.bundle.ie9.min.js.

Source versions

You can find the original JavaScript file in the src folder of this package.

AMD

meShowTransition has AMD support. This allows it to be lazy-loaded with an AMD loader, such as RequireJS.

2. Use meShowTransition

meShowTransition is initialized on the container you want to show/hide.

By default the widget will add the following classes to the container:

• me-shown while the container is shown and ready for any transitions
• me-show during the 'show' transition
• me-hide during the 'hide' transition

Define your CSS transitions. For example:

#example-container.me-shown {
  transform: translate(0,0);
}
#example-container,
#example-container.me-hide {
  transition: transform .5s ease 0s;
  transform: translate(-100%,0);
}

Initialize meShowTransition

/**
 * Create a new instance
 * @param container mixed; id or element; the container in which the focus should be maintained
 * @param show boolean; optional; show the container immediately (without transitions) onInit; default is false
 * @param options object; optional; overwrite the default options
 */
var myShowTransition = new meShowTransition(container [,show] [,options])

To show the container, call

myShowTransition.show(); // show with transition
myShowTransition.show(true); // show immediately (without transition)

To hide the container, call

myShowTransition.hide(); // hide with transition
myShowTransition.hide(true); // hide immediately (without transition)

To destroy the instance, call

myShowTransition = myShowTransition.destroy();

Customize

Default options

{
  callbacks: { // false or fn(params); params = {container: CONTAINER,immediate:BOOL (immediate show/hide call - no transition)}
    beforeShow: false,
    beforeShowTransition: false,
    afterShowTransition: false,
    afterShow: false,
    beforeHide: false,
    beforeHideTransition: false,
    afterHideTransition: false,
    afterHide: false
  },
  transitionEndElement: false, // element to listen to the transitionend event on (default is the container); use this if you use transitions on more than 1 element on show/hide to define the element which ends the transitions
  transitionMaxTime: 500, // ms; timeout to end the show/hide transition states in case the transitionEnd event doesn't fire; set to 0 to not support transition
  indicators: { // classes added to mark states
    shown: 'me-shown', // set to the container as long as it is shown
    show: 'me-show', // set to the container during the show-transition
    hide: 'me-hide' // set to the container during the hide-transition
  }
}

Package managers

You can install meShowTransition using npm.

$ npm install me-show-transition

License

meShowTransition is licenses under the MIT licence.