Merge branch 'impl-13342'; Closes #13342.

1 files changed, 6 insertions, 4 deletions

diff --git a/js/affix.js b/js/affix.js
index fc91936fb..c7e1b797e 100644
--- a/js/affix.js
+++ b/js/affix.js
@@ -15,7 +15,8 @@
 
   var Affix = function (element, options) {
     this.options = $.extend({}, Affix.DEFAULTS, options)
-    this.$window = $(window)
+
+    this.$target = $(this.options.target)
       .on('scroll.bs.affix.data-api', $.proxy(this.checkPosition, this))
       .on('click.bs.affix.data-api',  $.proxy(this.checkPositionWithEventLoop, this))
 
@@ -32,13 +33,14 @@
   Affix.RESET    = 'affix affix-top affix-bottom'
 
   Affix.DEFAULTS = {
-    offset: 0
+    offset: 0,
+    target: window
   }
 
   Affix.prototype.getPinnedOffset = function () {
     if (this.pinnedOffset) return this.pinnedOffset
     this.$element.removeClass(Affix.RESET).addClass('affix')
-    var scrollTop = this.$window.scrollTop()
+    var scrollTop = this.$target.scrollTop()
     var position  = this.$element.offset()
     return (this.pinnedOffset = position.top - scrollTop)
   }
@@ -51,7 +53,7 @@
     if (!this.$element.is(':visible')) return
 
     var scrollHeight = $(document).height()
-    var scrollTop    = this.$window.scrollTop()
+    var scrollTop    = this.$target.scrollTop()
     var position     = this.$element.offset()
     var offset       = this.options.offset
     var offsetTop    = offset.top