update Affix & BackTop

src/utils/dom.js

@@ -0,0 +1,37 @@
+import Vue from 'vue';
+
+const isServer = Vue.prototype.$isServer;
+
+/* istanbul ignore next */
+export const on = (function() {
+    if (!isServer && document.addEventListener) {
+        return function(element, event, handler) {
+            if (element && event && handler) {
+                element.addEventListener(event, handler, false);
+            }
+        };
+    } else {
+        return function(element, event, handler) {
+            if (element && event && handler) {
+                element.attachEvent('on' + event, handler);
+            }
+        };
+    }
+})();
+
+/* istanbul ignore next */
+export const off = (function() {
+    if (!isServer && document.removeEventListener) {
+        return function(element, event, handler) {
+            if (element && event) {
+                element.removeEventListener(event, handler, false);
+            }
+        };
+    } else {
+        return function(element, event, handler) {
+            if (element && event) {
+                element.detachEvent('on' + event, handler);
+            }
+        };
+    }
+})();