review code pattern consistency

app/reports/stock_movement.php

@@ -351,8 +351,8 @@
     // Reset UI
     $('#tbl_body').html('<tr><td colspan="9" class="text-center py-4 text-muted">Loading…</td></tr>');
     $('#lazy_sentinel').hide();
+    $('#lazy_loader').hide();
     $('#lazy_done').hide();
-    $('#lazy_loader').show();
     $('#result_summary').text('');
 
     // Reset stats
@@ -404,6 +404,7 @@
     }
 
     is_loading = true;
+    $('#lazy_loader').show();
     var sku = sku_queue[sku_index];
 
     return ajax_request({
@@ -427,21 +428,29 @@
           return;
         }
 
-        // If sentinel is still within the viewport (or above it),
-        // the table hasn't filled the window yet — keep loading immediately.
+        // If sentinel is still within the viewport keep loading immediately.
+        // Otherwise hide the spinner and wait for the IntersectionObserver to
+        // fire when the user scrolls close to the sentinel.
         if (sentinel_is_visible()) {
           load_next_sku();
+        } else {
+          $('#lazy_loader').hide();
         }
+      },
+      onError: function() {
+        is_loading = false;
+        $('#lazy_loader').hide();
       }
     });
   }
 
 
-  // ── Returns true if the sentinel is visible in the current viewport ───
+  // ── Returns true if the sentinel is within one window-height of the fold ─
   function sentinel_is_visible() {
     var el   = document.getElementById('lazy_sentinel');
     var rect = el.getBoundingClientRect();
-    return rect.top <= (window.innerHeight || document.documentElement.clientHeight);
+    var vh   = window.innerHeight || document.documentElement.clientHeight;
+    return rect.top <= vh * 2;
   }
 
 
@@ -614,10 +623,10 @@
   observer.observe(document.getElementById('lazy_sentinel'));
 
 
-  // ── Helpers ───────────────────────────────────────────────────────────
-  function fmt(n) {
-    return format_number(n, 2);
-  }
+  // ── Helpers ───────────────────────────────────────────────────────────
+  function fmt(n) {
+    return format_number(n, 2);
+  }
 
 
   // ── Export ───────────────────────────────────────────────────────────
@@ -697,4 +706,4 @@
   <script src="https://cdnjs.cloudflare.com/ajax/libs/jspdf-autotable/3.8.2/jspdf.plugin.autotable.min.js"></script>
 
 </body>
-</html>
+</html>