From 780e6d37aa8be9c4029ac5b520c95d9a179bea3f Mon Sep 17 00:00:00 2001
From: Timi Aiyemo <cozzbie@gmail.com>
Date: Fri, 8 Nov 2019 14:41:21 -0500
Subject: [PATCH] refactor window and Date object reference

---
 lazysizes-umd.js              |  8 +++-----
 lazysizes.js                  |  8 +++-----
 src/common.wrapper            |  2 +-
 src/lazysizes-core.js         | 10 ++++++----
 src/lazysizes-intersection.js |  8 +++-----
 5 files changed, 16 insertions(+), 20 deletions(-)

diff --git a/lazysizes-umd.js b/lazysizes-umd.js
index 035bed0f..3a0e94da 100644
--- a/lazysizes-umd.js
+++ b/lazysizes-umd.js
@@ -1,5 +1,5 @@
 (function(window, factory) {
-	var lazySizes = factory(window, window.document);
+	var lazySizes = factory(window, window.document, Date);
 	if(typeof module == 'object' && module.exports){
 		module.exports = lazySizes;
 	} else if (typeof define == 'function' && define.amd) {
@@ -7,7 +7,7 @@
 	} else {
 		window.lazySizes = lazySizes;
 	}
-}(window, function l(window, document) {
+}(window, function l(window, document, Date) {
 	'use strict';
 	/*jshint eqnull:true */
 
@@ -58,15 +58,13 @@
 
 	var docElem = document.documentElement;
 
-	var Date = window.Date;
-
 	var supportPicture = window.HTMLPictureElement;
 
 	var _addEventListener = 'addEventListener';
 
 	var _getAttribute = 'getAttribute';
 
-	var addEventListener = window[_addEventListener];
+	var addEventListener = window[_addEventListener].bind(window);
 
 	var setTimeout = window.setTimeout;
 
diff --git a/lazysizes.js b/lazysizes.js
index 8b42441c..7353240b 100644
--- a/lazysizes.js
+++ b/lazysizes.js
@@ -1,11 +1,11 @@
 (function(window, factory) {
-	var lazySizes = factory(window, window.document);
+	var lazySizes = factory(window, window.document, Date);
 	window.lazySizes = lazySizes;
 	if(typeof module == 'object' && module.exports){
 		module.exports = lazySizes;
 	}
 }(typeof window != 'undefined' ?
-      window : {}, function l(window, document) {
+      window : {}, function l(window, document, Date) {
 	'use strict';
 	/*jshint eqnull:true */
 
@@ -56,15 +56,13 @@
 
 	var docElem = document.documentElement;
 
-	var Date = window.Date;
-
 	var supportPicture = window.HTMLPictureElement;
 
 	var _addEventListener = 'addEventListener';
 
 	var _getAttribute = 'getAttribute';
 
-	var addEventListener = window[_addEventListener];
+	var addEventListener = window[_addEventListener].bind(window);
 
 	var setTimeout = window.setTimeout;
 
diff --git a/src/common.wrapper b/src/common.wrapper
index e4bee730..1b784d65 100644
--- a/src/common.wrapper
+++ b/src/common.wrapper
@@ -1,5 +1,5 @@
 (function(window, factory) {
-	var lazySizes = factory(window, window.document);
+	var lazySizes = factory(window, window.document, Date);
 	window.lazySizes = lazySizes;
 	if(typeof module == 'object' && module.exports){
 		module.exports = lazySizes;
diff --git a/src/lazysizes-core.js b/src/lazysizes-core.js
index 982026c5..2e3a727f 100644
--- a/src/lazysizes-core.js
+++ b/src/lazysizes-core.js
@@ -1,4 +1,4 @@
-function l(window, document) {
+function l(window, document, Date) { // Pass in the windoe Date function also for SSR because the Date class can be lost
 	'use strict';
 	/*jshint eqnull:true */
 
@@ -49,15 +49,17 @@ function l(window, document) {
 
 	var docElem = document.documentElement;
 
-	var Date = window.Date;
-
 	var supportPicture = window.HTMLPictureElement;
 
 	var _addEventListener = 'addEventListener';
 
 	var _getAttribute = 'getAttribute';
 
-	var addEventListener = window[_addEventListener];
+	/**
+	 * Update to bind to window because 'this' becomes null during SSR
+	 * builds.
+	 */
+	var addEventListener = window[_addEventListener].bind(window);
 
 	var setTimeout = window.setTimeout;
 
diff --git a/src/lazysizes-intersection.js b/src/lazysizes-intersection.js
index 1491c12b..df7be0c4 100644
--- a/src/lazysizes-intersection.js
+++ b/src/lazysizes-intersection.js
@@ -2,9 +2,9 @@
 	if(typeof module == 'object' && module.exports){
 		module.exports = lazySizes;
 	} else {
-		window.lazySizes = factory(window, window.document);
+		window.lazySizes = factory(window, window.document, Date);
 	}
-}(window, function l(window, document) {
+}(window, function l(window, document, Date) {
 	'use strict';
 
 	/*jshint eqnull:true */
@@ -14,15 +14,13 @@
 
 	var docElem = document.documentElement;
 
-	var Date = window.Date;
-
 	var supportPicture = window.HTMLPictureElement;
 
 	var _addEventListener = 'addEventListener';
 
 	var _getAttribute = 'getAttribute';
 
-	var addEventListener = window[_addEventListener];
+	var addEventListener = window[_addEventListener].bind(window);
 
 	var setTimeout = window.setTimeout;