ENH Call getCMSCompositeValidator() when saving Link DataObjects

src/Models/Link.php

@@ -16,6 +16,8 @@
 use SilverStripe\ORM\DataObject;
 use SilverStripe\ORM\FieldType\DBHTMLText;
 use SilverStripe\View\Requirements;
+use SilverStripe\Forms\Form;
+use SilverStripe\ORM\ValidationResult;
 
 /**
  * A Link Data Object. This class should be a subclass, and you should never directly interact with a plain Link
@@ -110,6 +112,28 @@ public function getCMSCompositeValidator(): CompositeValidator
         return $validator;
     }
 
+    /**
+     * This method is used to validate the dataobject before saving as part of DataObject::write()
+     * Linkfield works a bit differently from normal forms, because where the modal data is turned
+     * into JSON and saved into a single JsonField and in saveInto() the JSON is loaded into the
+     * dataobject using DataObject::setData($data)
+     * Because of this alternate method of saving, the getCMSCompositeValidator() isn't called
+     * so we need to call it manually here by loading it into a temporary Form
+     * 
+     * @return ValidationResult
+     */
+    public function validate()
+    {
+        $parentResult = parent::validate();
+        $validator = $this->getCMSCompositeValidator();
+        $form = Form::create(null, Form::DEFAULT_NAME, $this->getCMSFields());
+        $form->setValidator($validator);
+        $form->loadDataFrom($this);
+        $formResult = $form->validationResult();
+        $combinedResult = $parentResult->combineAnd($formResult);
+        return $combinedResult;
+    }
+
     /**
      * Form hook defined in @see Form::saveInto()
      * We use this to work with an in-memory only field