SPIKE Inline validation

src/Controllers/ElementalAreaController.php

@@ -15,6 +15,7 @@
 use SilverStripe\Core\Injector\Injector;
 use SilverStripe\Forms\Form;
 use SilverStripe\Security\SecurityToken;
+use SilverStripe\ORM\ValidationResult;
 
 /**
  * Controller for "ElementalArea" - handles loading and saving of in-line edit forms in an elemental area in admin
@@ -115,8 +116,9 @@ public function getElementForm($elementID)
      */
     public function apiSaveForm(HTTPRequest $request)
     {
+        $id = $this->urlParams['ID'] ?? 0;
         // Validate required input data
-        if (!isset($this->urlParams['ID'])) {
+        if ($id === 0) {
             $this->jsonError(400);
             return null;
         }
@@ -139,7 +141,7 @@ public function apiSaveForm(HTTPRequest $request)
         }
 
         /** @var BaseElement $element */
-        $element = BaseElement::get()->byID($this->urlParams['ID']);
+        $element = BaseElement::get()->byID($id);
         // Ensure the element can be edited by the current user
         if (!$element || !$element->canEdit()) {
             $this->jsonError(403);
@@ -149,6 +151,39 @@ public function apiSaveForm(HTTPRequest $request)
         // Remove the pseudo namespaces that were added by the form factory
         $data = $this->removeNamespacesFromFields($data, $element->ID);
 
+        // create a temporary Form to use for validation - will contain existing dataobject values
+        $form = $this->getElementForm($id);
+        // remove element namespaces from fields so that something like RequiredFields('Title') works
+        // element namespaces are added in DNADesign\Elemental\Forms\EditFormFactory
+        foreach ($form->Fields()->flattenFields() as $field) {
+            $rx = '#^PageElements_[0-9]+_#';
+            $namespacedName = $field->getName();
+            if (!preg_match($rx, $namespacedName)) {
+                continue;
+            }
+            $regularName = preg_replace($rx, '', $namespacedName);
+            // If there's an existing field with the same name, remove it
+            // this is probably a workaround for EditFormFactory creating too many fields?
+            // e.g. for element #2 there's a "Title" field and a "PageElements_2_Title" field
+            // same with "SecurityID" and "PageElements_2_SecurityID"
+            // possibly this would be better to just remove fields if they match the rx, not sure,
+            // this approach seems more conservative
+            if ($form->Fields()->flattenFields()->fieldByName($regularName)) {
+                $form->Fields()->removeByName($regularName);
+            }
+            // update the name of the field
+            $field->setName($regularName);
+        }
+        // merge submitted data into the form
+        $form->loadDataFrom($data);
+        // Validate the Form
+        /** @var ValidationResult|null $validationResult */
+        $validationResult = $form->getValidator()?->validate();
+        if ($validationResult && !$validationResult->isValid()) {
+            $this->jsonError(400, $validationResult->getMessages());
+            return null;
+        }
+
         try {
             $updated = false;