Angular eventListener from Directive - angularjs

Question

I have directive, essentially a button, that should only show on certain conditions. It uses addEventListener('scroll') to capture the scroll of a <ion-content> element in the containing page. This works fine for one page/view but when navigating to another page/view the scroll event is not fired?
'use strict';
angular.module('Fmpclient')
.directive('fmpRefreshButton', ['$window', '$ionicScrollDelegate', 'RefreshButtonService', function ($window, $ionicScrollDelegate, RefreshButtonService) {
var hideDelayTime = 3500;
var isButtonVisible = false;
var lastYPos = 0; // store the last Y Position
var timerId = null; // store a setTimeout id for later use
var $scrollEl = null;
var refreshButton = null;
/* __ code snipped for brevity __ */
/**
Work out the direction of scroll so we can
either hide or show the refresh button according to AC
#method onScroll
#public
*/
function onScroll () {
var scrollTop = $ionicScrollDelegate.getScrollPosition().top;
if(scrollTop > lastYPos) {
// Scrolling DOWN - hide refresh button
hideRefreshButton();
} else {
// Scrolling UP - show refresh button
shouldRefreshFeed();
}
// Store the last Y position to determine
// direction of scroll on next iteration
lastYPos = scrollTop;
}
/**
Setup directive elements on init
#method init
#public
*/
function init (){
console.log('directive::init()');
RefreshButtonService.setRefreshFeed(false);
$scrollEl = document.getElementById('ionContentScroll');
if($scrollEl){
$scrollEl.addEventListener('scroll', onScroll);
}
}
function _link(scope, element) {
refreshButton = element[0];
init();
}
return {
templateUrl: 'app/app/refresh-button/refresh-button.directive.html',
restrict: 'AE',
scope: true,
link: _link,
};
}
]);

Answer 1

As suggested by Scott, in the comment above, the solution to my rather trivial problem was to pass in the id as a parameter to the directive to ensure the id can be unique for each usage:
In the Directive scope:
scope: {
scrollElement: '='
},
and passed in on the Directive template:
<my-directive scroll-element="ionFeedScroll">