1 files changed, 23 insertions, 6 deletions
diff --git a/src/js/utils.js b/src/js/utils.js
index a58d8555..0c5a28d7 100644
--- a/src/js/utils.js
+++ b/src/js/utils.js
@@ -120,6 +120,21 @@ const utils = {
         });
     },
 
+    // Load image avoiding xhr/fetch CORS issues
+    // Server status can't be obtained this way unfortunately, so this uses "naturalWidth" to determine if the image has loaded.
+    // By default it checks if it is at least 1px, but you can add a second argument to change this.
+    loadImage(src, minWidth = 1) {
+        return new Promise((resolve, reject) => {
+            const image = new Image();
+            const handler = () => {
+                delete image.onload;
+                delete image.onerror;
+                (image.naturalWidth >= minWidth ? resolve : reject)(image);
+            };
+            Object.assign(image, {onload: handler, onerror: handler, src});
+        });
+    },
+
     // Load an external script
     loadScript(url) {
         return new Promise((resolve, reject) => {
@@ -393,14 +408,16 @@ const utils = {
         }
     },
 
-    // Toggle class on an element
-    toggleClass(element, className, toggle) {
+    // Mirror Element.classList.toggle, with IE compatibility for "force" argument
+    toggleClass(element, className, force) {
         if (utils.is.element(element)) {
-            const contains = element.classList.contains(className);
-
-            element.classList[toggle ? 'add' : 'remove'](className);
+            let method = 'toggle';
+            if (typeof force !== 'undefined') {
+                method = force ? 'add' : 'remove';
+            }
 
-            return (toggle && !contains) || (!toggle && contains);
+            element.classList[method](className);
+            return element.classList.contains(className);
         }
 
         return null;