Fix issue with massactions only selecting first item

Author: jissereitsma

view/adminhtml/templates/grid/massactions.phtml

@@ -37,7 +37,9 @@ if (empty($massActions)) {
     </div>
 
     <form method="post" x-ref="massActionForm">
-        <input type="hidden" name="selected[]" x-ref="massActionFormIds" />
+        <template x-for="id in getSelectedIds" :key="id">
+            <input type="hidden" name="selected[]" :value="id">
+        </template>
         <input type="hidden" name="namespace" value="<?= $escaper->escapeHtml($viewModel->getNamespace()) ?>" />
         <input type="hidden" name="loki_redirect_url" value="<?= /* @noEscape */ $viewModel->getCurrentUrl() ?>" />
         <?= /* @noEscape */ $block->getBlockHtml('formkey') ?>

view/adminhtml/templates/script/component-partial/mass-actions-component-partial.phtml

@@ -26,7 +26,6 @@ use Magento\Framework\View\Element\Template;
                 return;
             }
 
-            this.$refs.massActionFormIds.value = selectedIds;
             this.$refs.massActionForm.action = this.$el.getAttribute('data-url');
             this.$refs.massActionForm.submit();
         }

view/adminhtml/templates/script/component-partial/selected-component-partial.phtml

@@ -13,6 +13,9 @@ use Magento\Framework\View\Element\Template;
         initSelectedIds() {
             this.selectedIds = new Set([]);
         },
+        getSelectedIds() {
+            return Array.from(this.selectedIds);
+        },
         getSelectedIdCount() {
             if (this.selectedIds.has('ALL')) {
                 return this.totalItems;