Ensure read only values don't get lost on submit

Author: Dominic Tubach

src/Form/Control/Util/BasicFormPropertiesFactory.php

@@ -83,9 +83,18 @@ public static function createFieldProperties(ControlDefinition $definition, Form
       '#_nullable' => $definition->isNullable(),
     ];
 
+    $readOnlyValuePath = array_merge(['readOnlyValues'], $definition->getPropertyPath());
     if ((!$formState->isCached() || $definition->isReadOnly())
-      && $formState->hasTemporaryValue($definition->getPropertyPath())) {
+      && $formState->hasTemporaryValue($definition->getPropertyPath())
+    ) {
       $form['#default_value'] = $formState->getTemporaryValue($definition->getPropertyPath());
+      if ($definition->isReadOnly() && !$definition->isCalculated()) {
+        // Ensure read only values don't get lost on submit.
+        $formState->set($readOnlyValuePath, $form['#default_value']);
+      }
+    }
+    elseif ($definition->isReadOnly() && $formState->has($readOnlyValuePath)) {
+      $form['#default_value'] = $formState->get($readOnlyValuePath);
     }
     elseif (NULL !== $definition->getDefault()) {
       $form['#default_value'] = $definition->getDefault();

src/JsonForms/Definition/Control/ControlDefinition.php

@@ -338,13 +338,17 @@ public function getType(): string {
     return $this->propertySchema->type;
   }
 
+  public function isCalculated(): bool {
+    return property_exists($this->propertySchema, '$calculate');
+  }
+
   public function isNullable(): bool {
     return in_array('null', (array) $this->propertySchema->type, TRUE);
   }
 
   public function isReadOnly(): bool {
     return $this->controlSchema->options->readonly ?? $this->propertySchema->readOnly
-      ?? (property_exists($this->propertySchema, '$calculate') || $this->parentUiReadonly);
+      ?? ($this->isCalculated() || $this->parentUiReadonly);
   }
 
   /**