From b38540d1ff65a98217098db45061115394af5588 Mon Sep 17 00:00:00 2001
From: Gaspard Jankowiak <gaspard.jankowiak@uni-graz.at>
Date: Wed, 24 Sep 2025 08:46:49 +0200
Subject: [PATCH] prevent activation for empty groups

---
 directory.js | 95 ++++++++++++++++++++++++++++------------------------
 1 file changed, 51 insertions(+), 44 deletions(-)

diff --git a/directory.js b/directory.js
index b140e7e..999584d 100644
--- a/directory.js
+++ b/directory.js
@@ -4,53 +4,57 @@ const C = document.createElement;
 const ordNrRegex = /.*pOrgNr=([0-9]+).*/gm;
 const personalIDRegex = /.*pStPersonNr=([0-9]+).*/gm;
 
-function appendLink() {
+function appendLink(nonEmptyGroup) {
   if (document.getElementById("kf-trombi_row")) return;
 
   var row_header = document.createElement("th");
   row_header.textContent = "Trombi";
 
-  var link = document.createElement("a");
-  link.textContent = "Toggle";
-  link.href="#";
-  link.addEventListener("click", toggleTrombi);
-
-  var slider = document.createElement("input");
-  slider.id = "kf-trombi_columns_slider";
-  slider.type = "range";
-  slider.value = 5;
-  slider.min = 3;
-  slider.max = 8;
-
-  var column_nr = document.createElement("span");
-  column_nr.id = "kf-trombi_column_nr";
-  column_nr.textContent = slider.value;
-  var column_label = document.createElement("span");
-  column_label.textContent = " columns";
-
-  slider.addEventListener("input", (event) => {
-    column_nr.textContent = slider.value;
-    const trombi = document.getElementById("kf-trombi_trombi");
-    trombi.classList.remove( "kf-trombi_trombi_3", "kf-trombi_trombi_4", "kf-trombi_trombi_5", "kf-trombi_trombi_6", "kf-trombi_trombi_7", "kf-trombi_trombi_8" );
-    trombi.classList.add(`kf-trombi_trombi_${slider.value}`);
-  })
-
-  enhanced_checkbox = document.createElement("input");
-  enhanced_checkbox.id = "kf-trombi_enhanced_checkbox";
-  enhanced_checkbox.type = "checkbox";
-  enhanced_checkbox.checked = true;
-
-  var enhance_label = document.createElement("label");
-  enhance_label.textContent = " enhance";
-  enhance_label.htmlFor = "kf-trombi_enhanced_checkbox";
-
-  enhanced_checkbox.addEventListener("input", (event) => {
-    const trombi = document.getElementById("kf-trombi_trombi");
-    trombi.classList.toggle('kf-trombi_enhanced');
-  })
-
   var row_links = document.createElement("td");
-  row_links.append(link, slider, column_nr, column_label, enhanced_checkbox, enhance_label);
+
+  if (nonEmptyGroup) {
+    var link = document.createElement("a");
+    link.textContent = "Toggle";
+    link.href="#";
+    link.addEventListener("click", toggleTrombi);
+
+    var slider = document.createElement("input");
+    slider.id = "kf-trombi_columns_slider";
+    slider.type = "range";
+    slider.value = 5;
+    slider.min = 3;
+    slider.max = 8;
+
+    var column_nr = document.createElement("span");
+    column_nr.id = "kf-trombi_column_nr";
+    column_nr.textContent = slider.value;
+    var column_label = document.createElement("span");
+    column_label.textContent = " columns";
+
+    slider.addEventListener("input", (event) => {
+      column_nr.textContent = slider.value;
+      const trombi = document.getElementById("kf-trombi_trombi");
+      trombi.classList.remove( "kf-trombi_trombi_3", "kf-trombi_trombi_4", "kf-trombi_trombi_5", "kf-trombi_trombi_6", "kf-trombi_trombi_7", "kf-trombi_trombi_8" );
+      trombi.classList.add(`kf-trombi_trombi_${slider.value}`);
+    })
+
+    enhanced_checkbox = document.createElement("input");
+    enhanced_checkbox.id = "kf-trombi_enhanced_checkbox";
+    enhanced_checkbox.type = "checkbox";
+    enhanced_checkbox.checked = true;
+
+    var enhance_label = document.createElement("label");
+    enhance_label.textContent = " enhance";
+    enhance_label.htmlFor = "kf-trombi_enhanced_checkbox";
+
+    enhanced_checkbox.addEventListener("input", (event) => {
+      const trombi = document.getElementById("kf-trombi_trombi");
+      trombi.classList.toggle('kf-trombi_enhanced');
+    })
+    row_links.append(link, slider, column_nr, column_label, enhanced_checkbox, enhance_label);
+  } else {
+    row_links.textContent = "empty group!"
+  }
 
   var tr = document.createElement("tr");
   tr.classList.add("coNavGroup");
@@ -128,6 +132,9 @@ if (document.getElementById("kf-trombi_trombi")) {
   document.getElementById("kf-trombi_row").remove();
 }
 
-appendLink();
-generateTrombi();
-
+// only enable on non-empty groups
+const nonEmptyGroup = (document.getElementsByClassName("cNoEntry").length == 0);
+appendLink(nonEmptyGroup);
+if (nonEmptyGroup) {
+  generateTrombi();
+}