fix ios cache busting on preview fix

Author: reloxx13

assets/js/preview.js

@@ -1,5 +1,28 @@
 /* eslint n/no-unsupported-features/node-builtins: "off" */
 /* globals photoBooth photoboothTools */
+
+function addCacheBustingParam() {
+    const url = getBasePreviewUrl();
+    const timestamp = new Date().getTime();
+
+    if (url.includes('?')) {
+        return `${url}&t=${timestamp}`;
+    }
+
+    return `${url}?t=${timestamp}`;
+}
+
+function getBasePreviewUrl() {
+    if (!config.preview || !config.preview.url) {
+        return '';
+    }
+
+    const raw = config.preview.url;
+    const match = raw.match(/^url\((['"]?)(.+?)\1\)$/);
+
+    return match ? match[2] : raw;
+}
+
 const photoboothPreview = (function () {
     // vars
     const CameraDisplayMode = {
@@ -163,6 +186,7 @@ const photoboothPreview = (function () {
                 } else if (config.preview.mode === PreviewMode.URL.valueOf()) {
                     photoboothTools.console.logDev('Preview: Preview at countdown from URL.');
                     setTimeout(function () {
+                        url.css('background-image', 'url("' + addCacheBustingParam() + '")');
                         url.show();
                         url.addClass('streaming');
                     }, config.preview.url_delay);
@@ -175,6 +199,7 @@ const photoboothPreview = (function () {
                 } else if (config.preview.mode === PreviewMode.URL.valueOf()) {
                     photoboothTools.console.logDev('Preview: Preview from URL.');
                     setTimeout(function () {
+                        url.css('background-image', 'url("' + addCacheBustingParam() + '")');
                         url.show();
                         url.addClass('streaming');
                     }, config.preview.url_delay);
@@ -203,6 +228,7 @@ const photoboothPreview = (function () {
         }
         url.removeClass('streaming');
         url.hide();
+        url.css('background-image', 'none');
         video.hide();
         pictureFrame.hide();
         collageFrame.hide();