From c5197928b12861599338a87dda9562ff16782332 Mon Sep 17 00:00:00 2001
From: Gregor Kleen <gregor.kleen@ifi.lmu.de>
Date: Fri, 7 Feb 2020 21:33:32 +0100
Subject: [PATCH] feat(hide-columns): don't break on dom changes

---
 frontend/src/utils/hide-columns/hide-columns.js | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/frontend/src/utils/hide-columns/hide-columns.js b/frontend/src/utils/hide-columns/hide-columns.js
index 0c0187f23..77382e322 100644
--- a/frontend/src/utils/hide-columns/hide-columns.js
+++ b/frontend/src/utils/hide-columns/hide-columns.js
@@ -31,6 +31,8 @@ export class HideColumns {
 
   _autoHide;
 
+  _mutationObserver;
+
   headerToHider = new Map();
   hiderToHeader = new Map();
 
@@ -69,6 +71,9 @@ export class HideColumns {
     }
 
     [...this._element.querySelectorAll('th')].filter(th => !th.hasAttribute(HIDE_COLUMNS_NO_HIDE)).forEach(th => this.setupHideButton(th));
+
+    this._mutationObserver = new MutationObserver(this._tableMutated.bind(this));
+    this._mutationObserver.observe(this._element, { childList: true, subtree: true });
   }
 
   setupHideButton(th) {
@@ -217,6 +222,15 @@ export class HideColumns {
     hider.style.top  = thR.height + 'px';
   }
 
+  _tableMutated(mutationList, observer) {
+    console.log('_tableMutated', mutationList, observer);
+    
+    if (!Array.from(mutationList).some(mutation => mutation.type === 'childList'))
+      return;
+
+    [...this._element.querySelectorAll('th')].filter(th => !th.hasAttribute(HIDE_COLUMNS_NO_HIDE)).forEach(th => this.updateColumnDisplay(this.colIndex(th), this.isHiddenColumn(th)));
+  }
+
   getStorageKey(th) {
     // get handler name
     const handlerIdent = document.querySelector('[uw-handler]').getAttribute('uw-handler');