ENH: Insert / edit link button label.

_config/config.yml

@@ -17,3 +17,7 @@ SilverStripe\Forms\TreeDropdownField:
 SilverStripe\CMS\Forms\AnchorSelectorField:
   extensions:
     - SilverStripe\LinkField\Extensions\AjaxField
+
+SilverStripe\LinkField\Form\FormFactory:
+  extensions:
+    - SilverStripe\LinkField\Extensions\FormFactoryExtension

src/Extensions/FormFactoryExtension.php

@@ -0,0 +1,55 @@
+<?php
+
+namespace SilverStripe\LinkField\Extensions;
+
+use SilverStripe\Control\RequestHandler;
+use SilverStripe\Core\Extension;
+use SilverStripe\Forms\FieldList;
+use SilverStripe\Forms\FormAction;
+use SilverStripe\LinkField\Form\FormFactory;
+use SilverStripe\LinkField\Models\Link;
+
+/**
+ * Enhance the insert / edit link button label to match the model data state
+ *
+ * @method FormFactory getOwner()
+ */
+class FormFactoryExtension extends Extension
+{
+    /**
+     * Extension point in @see FormFactory::getFormActions()
+     *
+     * @param FieldList $actions
+     * @param RequestHandler $controller
+     * @param string $name
+     * @param array $context
+     * @return void
+     */
+    public function updateFormActions(FieldList $actions, RequestHandler $controller, string $name, array $context): void
+    {
+        if (!array_key_exists('LinkType', $context)) {
+            // We couldn't find any link model
+            return;
+        }
+
+        /** @var Link $linkType */
+        $linkType = $context['LinkType'];
+
+        if (!$linkType->exists()) {
+            // This is a new link, so we don't need to to any further customisation
+            return;
+        }
+
+        /** @var FormAction $insertAction */
+        $insertAction = $actions->fieldByName('action_insert');
+
+        if (!$insertAction) {
+            // We couldn't find the insert action
+            return;
+        }
+
+        // Update the title of the action to reflect the link model data state
+        $insertActionTitle = _t('Admin.EDIT_LINK', 'Edit link');
+        $insertAction->setTitle($insertActionTitle);
+    }
+}