问题
I'm using bootstrap 4 which dropped the affix plugin, to be replaced by using position: sticky.
However, chrome does not support that yet. And when moving back to bootstrap 3 whole my layout is screwed. And the recommended scrollpos-styler works horrible in combination with bootstrap. (https://github.com/acch/scrollpos-styler)
So I wondered, is it possible to get the affix plugin separate so I can still use it with bootstrap 4?
回答1:
Yes, you can.
You can copy the plugin from Bootstrap 3. Do not forget to to declare the required CSS classes:
.affix {
position: fixed;
top: 1rem;
}
.affix-bottom {
position: absolute;
}
Demo:
<!DOCTYPE html>
<html lang="en">
<head>
<!-- Required meta tags always come first -->
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no">
<meta http-equiv="x-ua-compatible" content="ie=edge">
<title> Bootstrap 4 project :: Home</title>
<!--Bootstrap CSS -->
<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/twitter-bootstrap/4.0.0-alpha.2/css/bootstrap.min.css">
<style>
.affix {
position: fixed;
top: 1rem;
}
.affix-bottom {
position: absolute;
}
</style>
</head>
<body>
<header style="height:200px;background-color:green;color:white">header</header>
<div class="container">
<div class="row">
<div class="col-md-3">
<div data-spy="affix" data-offset-top="200" data-offset-bottom="200" style="background-color:red; height:250px;">
Affixed sidebar
</div>
</div>
<div class="col-md-9" style="height:150vh;">
Content
</div>
</div>
</div>
<footer style="height:200px;background-color:black;color:white;">footer</footer>
<!-- jQuery first, then Bootstrap JS. -->
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.4/jquery.min.js"></script>
<script src="https://cdn.rawgit.com/HubSpot/tether/v1.2.0/dist/js/tether.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/twitter-bootstrap/4.0.0-alpha.2/js/bootstrap.min.js"></script>
<script>
/* ========================================================================
* Bootstrap: affix.js v3.3.6
* http://getbootstrap.com/javascript/#affix
* ========================================================================
* Copyright 2011-2015 Twitter, Inc.
* Licensed under MIT (https://github.com/twbs/bootstrap/blob/master/LICENSE)
* ======================================================================== */
+function ($) {
'use strict';
// AFFIX CLASS DEFINITION
// ======================
var Affix = function (element, options) {
this.options = $.extend({}, Affix.DEFAULTS, options)
this.$target = $(this.options.target)
.on('scroll.bs.affix.data-api', $.proxy(this.checkPosition, this))
.on('click.bs.affix.data-api', $.proxy(this.checkPositionWithEventLoop, this))
this.$element = $(element)
this.affixed = null
this.unpin = null
this.pinnedOffset = null
this.checkPosition()
}
Affix.VERSION = '3.3.6'
Affix.RESET = 'affix affix-top affix-bottom'
Affix.DEFAULTS = {
offset: 0,
target: window
}
Affix.prototype.getState = function (scrollHeight, height, offsetTop, offsetBottom) {
var scrollTop = this.$target.scrollTop()
var position = this.$element.offset()
var targetHeight = this.$target.height()
if (offsetTop != null && this.affixed == 'top') return scrollTop < offsetTop ? 'top' : false
if (this.affixed == 'bottom') {
if (offsetTop != null) return (scrollTop + this.unpin <= position.top) ? false : 'bottom'
return (scrollTop + targetHeight <= scrollHeight - offsetBottom) ? false : 'bottom'
}
var initializing = this.affixed == null
var colliderTop = initializing ? scrollTop : position.top
var colliderHeight = initializing ? targetHeight : height
if (offsetTop != null && scrollTop <= offsetTop) return 'top'
if (offsetBottom != null && (colliderTop + colliderHeight >= scrollHeight - offsetBottom)) return 'bottom'
return false
}
Affix.prototype.getPinnedOffset = function () {
if (this.pinnedOffset) return this.pinnedOffset
this.$element.removeClass(Affix.RESET).addClass('affix')
var scrollTop = this.$target.scrollTop()
var position = this.$element.offset()
return (this.pinnedOffset = position.top - scrollTop)
}
Affix.prototype.checkPositionWithEventLoop = function () {
setTimeout($.proxy(this.checkPosition, this), 1)
}
Affix.prototype.checkPosition = function () {
if (!this.$element.is(':visible')) return
var height = this.$element.height()
var offset = this.options.offset
var offsetTop = offset.top
var offsetBottom = offset.bottom
var scrollHeight = Math.max($(document).height(), $(document.body).height())
if (typeof offset != 'object') offsetBottom = offsetTop = offset
if (typeof offsetTop == 'function') offsetTop = offset.top(this.$element)
if (typeof offsetBottom == 'function') offsetBottom = offset.bottom(this.$element)
var affix = this.getState(scrollHeight, height, offsetTop, offsetBottom)
if (this.affixed != affix) {
if (this.unpin != null) this.$element.css('top', '')
var affixType = 'affix' + (affix ? '-' + affix : '')
var e = $.Event(affixType + '.bs.affix')
this.$element.trigger(e)
if (e.isDefaultPrevented()) return
this.affixed = affix
this.unpin = affix == 'bottom' ? this.getPinnedOffset() : null
this.$element
.removeClass(Affix.RESET)
.addClass(affixType)
.trigger(affixType.replace('affix', 'affixed') + '.bs.affix')
}
if (affix == 'bottom') {
this.$element.offset({
top: scrollHeight - height - offsetBottom
})
}
}
// AFFIX PLUGIN DEFINITION
// =======================
function Plugin(option) {
return this.each(function () {
var $this = $(this)
var data = $this.data('bs.affix')
var options = typeof option == 'object' && option
if (!data) $this.data('bs.affix', (data = new Affix(this, options)))
if (typeof option == 'string') data[option]()
})
}
var old = $.fn.affix
$.fn.affix = Plugin
$.fn.affix.Constructor = Affix
// AFFIX NO CONFLICT
// =================
$.fn.affix.noConflict = function () {
$.fn.affix = old
return this
}
// AFFIX DATA-API
// ==============
$(window).on('load', function () {
$('[data-spy="affix"]').each(function () {
var $spy = $(this)
var data = $spy.data()
data.offset = data.offset || {}
if (data.offsetBottom != null) data.offset.bottom = data.offsetBottom
if (data.offsetTop != null) data.offset.top = data.offsetTop
Plugin.call($spy, data)
})
})
}(jQuery);
</script>
<script>
$('[data-spy="affix"]').on('affixed.bs.affix', function () {
// from http://stackoverflow.com/questions/6551429/adjust-a-width-based-on-parent-w-jquery
$(".affix").css("width",$(".affix").parent().css("width").replace('px','') - 30);
})
</script>
</body>
</html>回答2:
It works with jquery but it is not listed at the jquery plugins. Instead it is included with bootstrap 3.
https://github.com/twbs/bootstrap/releases
来源：https://stackoverflow.com/questions/36911695/affix-as-separate-plugin