sorting in js-tables

resources/app/stylesheets/app.less

@@ -251,6 +251,16 @@ table {
         th {
             padding: @text-padding-v @text-padding-h @text-padding-v + .3rem @text-padding-v;
         }
+
+        th[data-sort=desc]::after {
+            content: "🠻";
+            display: inline;
+        }
+
+        th[data-sort=asc]::after {
+            content: "🠹";
+            display: inline;
+        }
     }
 
     tbody {

resources/public/js/scripts.js

@@ -55,6 +55,10 @@ document.addEventListener('DOMContentLoaded', function () {
               function (arg2) {
                   fn(arg1, arg2)
               }
+        const partial21 = (fn, arg1, arg2) =>
+              function(arg3) {
+                  fn(arg1, arg2, arg3)
+              }
 
         function toggleVisibilities(tbl, ixsToShow) {
             tblRows(tbl).forEach(function (row, ix) {
@@ -222,9 +226,52 @@ document.addEventListener('DOMContentLoaded', function () {
             return ctx
         }
 
+        function flipSortDir(dir) {
+            return (dir || 'asc') == 'asc' ? 'desc' : 'asc'
+        }
+
+        function clearSortAttributes(tbl) {
+            [...tbl.tHead.rows[0].cells]
+                .forEach(th => th.removeAttribute('data-sort'))
+        }
+
+        function onSort(ctx, ix, event) {
+            const tbl = ctx.tbl
+            console.debug(tbl, ix, event)
+
+            const sortDir = event.target.getAttribute('data-sort') || 'asc'
+            const sortMod = sortDir == 'asc' ? 1 : -1;
+
+            const rows = tblRows(tbl)
+            const newTbody = document.createElement('tbody')
+
+            rows.sort((row1, row2) => {
+                const val1 = row1.cells[ix].textContent
+                const val2 = row2.cells[ix].textContent
+                return sortMod * (val1 > val2 ? 1
+                                  : val2 > val1 ? -1
+                                  : 0);
+            })
+
+            rows.forEach(row => newTbody.appendChild(row))
+            tbl.replaceChild(newTbody, tbl.tBodies[0])
+
+            clearSortAttributes(tbl)
+            event.target.setAttribute('data-sort', flipSortDir(sortDir))
+            changePage(ctx, 0)
+        }
+
+        function enableSorting(ctx) {
+            const ths = ctx.tbl.querySelectorAll('thead th')
+            ths.forEach((th, ix) => {
+                th.addEventListener('click', partial21(onSort, ctx, ix))
+            })
+        }
+
         document.querySelectorAll('table').forEach(function (tbl) {
             const ctx = addToolbar(tbl)
             changePage(ctx, 0)
+            enableSorting(ctx)
         })
     }