jquery-enter-leave

Simplifies animating elements added or removed to the DOM. Greatly inspired by functionality in Angular's ngAnimate.

Introduction

Exposes two functions on jQuery instances, enter and leave. enter should be used to animate inserts into the DOM, and leave is used to animate removals.

Install

npm install jquery-enter-leave

Simply make sure to require('jquery-enter-leave') to load the plugin. If you want to load the toggle, show and hide methods, also require('jquery-enter-leave/toggle').

enter and leave

Sample JS:

$('main > .page').leave(options);
 
page.enter($('main'), options, function() {
    console.log('done');
});

Sample SCSS:

main {
    @include clear;
    flex: 1 0 auto;
    overflow-x: hidden;//needed to fix chrome animation bug (logo seems to move); 
 
    > .page {
        width: 100%;
        position: relative;
        left: 0;
        &.animate {
            transition: left $transition-time;
            float: left;
            margin-right: -100%;
        }
        &.enter {
            left: 100%;
            &.back {
                left: -100%;
            }
        }
 
        &.leave.active {
            left: -100%;
            &.back {
                left: 100%;
            }
        }
        &.enter.active, &.leave {
            left: 0;
        }
    }
}

toggle, show and hide

The jquery-enter-leave/toggle module overwrites the default toggle, show and hide methods. However, the custom logic is only used if !!options.transition === true, otherwise control will be passed over the original method.

$('.question').on('click', function() {
    $(this).next('.answer').toggle({ transition: true });
});

CAUTION!: jQuery will call this.animate inside these methods if an object is passed as a parameter. So passing enter-leave options but forgetting to pass transtion: true will call jQuery's animate. IE do not do (for example) $el.show({ animateHeight: true }).

className

A custom class to add and remove.

animateHeight

Since animating to height: auto with CSS is not possible, one needs to pass the animateHeight: true. This will set some inline CSS, using $(this).css('height', this.scrollHeight);.

Sample SCSS:

&.animate {
    transition: height 0.5s;
}
 
&.enter:not(.active), &.leave.active {
    height: 0 !important;
}