luci-base: add additional information to upload modal

Sometimes it would be useful to display additional information in the
modal (e.g. if upload takes some time on slower devices and feedback it
so the user knows about the delay).

Signed-off-by: Christian Korber <ckorber@tdt.de>

modules/luci-base/htdocs/luci-static/resources/ui.js

@@ -4924,12 +4924,16 @@ const UI = baseclass.extend(/** @lends LuCI.ui.prototype */ {
 	 * An optional DOM text node whose content text is set to the progress
 	 * percentage value during file upload.
 	 *
+	 * @param {string} [info]
+	 * An optional string that carries additional information that should
+	 * be shown under the progressbar.
+	 *
 	 * @returns {Promise<LuCI.ui.FileUploadReply>}
 	 * Returns a promise resolving to a file upload status object on success
 	 * or rejecting with an error in case the upload failed or has been
 	 * cancelled by the user.
 	 */
-	uploadFile(path, progressStatusNode) {
+	uploadFile(path, progressStatusNode, info) {
 		return new Promise((resolveFn, rejectFn) => {
 			UI.prototype.showModal(_('Uploading file…'), [
 				E('p', _('Please select the file to upload.')),
@@ -4985,7 +4989,11 @@ const UI = baseclass.extend(/** @lends LuCI.ui.prototype */ {
 
 								const progress = E('div', { 'class': 'cbi-progressbar', 'title': '0%' }, E('div', { 'style': 'width:0' }));
 
-								UI.prototype.showModal(_('Uploading file…'), [ progress ]);
+								let infoNode;
+								if (info)
+									infoNode = E('p', _('%s').format(info));
+
+								UI.prototype.showModal(_('Uploading file…'), [ progress, infoNode ? infoNode : null ]);
 
 								const data = new FormData();