PRE_TRANSFORM and POST_TRANSFORM events when using serializer to transform object to elastica document

[rahit]

It is already mentioned in issue #1142 that, POST_TRANSFORM event does not trigger when object serialization is enabled. This is also true for PRE_TRANSFORM event.

This events mainly triggered in transformObjectToDocument() method of ModelToElasticaAutoTransformer class.

// Transformer/ModelToElasticaAutoTransformer.php
protected function transformObjectToDocument($object, array $fields, $identifier = '')
    {
        $document = new Document($identifier);

        if ($this->dispatcher) {
            $event = new TransformEvent($document, $fields, $object);
            $this->dispatcher->dispatch(TransformEvent::PRE_TRANSFORM, $event);

            $document = $event->getDocument();
        }

        foreach ($fields as $key => $mapping) {
            if ($key == '_parent') {
                $property = (null !== $mapping['property']) ? $mapping['property'] : $mapping['type'];
                $value = $this->propertyAccessor->getValue($object, $property);
                $document->setParent($this->propertyAccessor->getValue($value, $mapping['identifier']));

                continue;
            }

            $path = isset($mapping['property_path']) ?
                $mapping['property_path'] :
                $key;
            if (false === $path) {
                continue;
            }
            $value = $this->propertyAccessor->getValue($object, $path);

            if (isset($mapping['type']) && in_array(
                    $mapping['type'], array('nested', 'object')
                ) && isset($mapping['properties']) && !empty($mapping['properties'])
            ) {
                /* $value is a nested document or object. Transform $value into
                 * an array of documents, respective the mapped properties.
                 */
                $document->set($key, $this->transformNested($value, $mapping['properties']));

                continue;
            }

            if (isset($mapping['type']) && $mapping['type'] == 'attachment') {
                // $value is an attachment. Add it to the document.
                if ($value instanceof \SplFileInfo) {
                    $document->addFile($key, $value->getPathName());
                } else {
                    $document->addFileContent($key, $value);
                }

                continue;
            }

            $document->set($key, $this->normalizeValue($value));
        }

        if ($this->dispatcher) {
            $event = new TransformEvent($document, $fields, $object);
            $this->dispatcher->dispatch(TransformEvent::POST_TRANSFORM, $event);

            $document = $event->getDocument();
        }

        return $document;
    }

trunsform() method utilize this transformObjectToDocument() method to do the conversion.

// Transformer/ModelToElasticaAutoTransformer.php
public function transform($object, array $fields)
    {
        $identifier = $this->propertyAccessor->getValue($object, $this->options['identifier']);
        $document = $this->transformObjectToDocument($object, $fields, $identifier);

        return $document;
    }

But this is not the case for serialize persister. ObjectSerializePersister uses ModelToElasticaIdentifierTransformer which overrides the transform() method.

// Transformer/ModelToElasticaIdentifierTransformer.php
class ModelToElasticaIdentifierTransformer extends ModelToElasticaAutoTransformer
{
    /**
     * Creates an elastica document with the id of the doctrine object as id.
     *
     * @param object $object the object to convert
     * @param array  $fields the keys we want to have in the returned array
     *
     * @return Document
     **/
    public function transform($object, array $fields)
    {
        $identifier = $this->propertyAccessor->getValue($object, $this->options['identifier']);

        return new Document($identifier);
    }
}

ObjectSerializerPersister utilizes transformToElasticaDocument($object) to call transform method above.

// Persister/ObjectSerializerPersister.php
public function transformToElasticaDocument($object)
    {
        $document = $this->transformer->transform($object, array());

        $data = call_user_func($this->serializer, $object);
        $document->setData($data);

        return $document;
    }

This is why PRE_TRANSFORM and POST_TRANSFORM are not triggered while using serializer. I can make a PR to solve the issue. Waiting for feedback.

[giovannialbero1992]

You can see this #1146

[rahit]

@giovannialbero1992 , I have seen this issue when I was searching for the problem. It does solve the issue with POST_TRANSFORM. What about PRE_TRANSFORM?

[giovannialbero1992]

@rahit I've not added the PRE_TRANSFORM event, but it's possible to add it.

[rahit]

@giovannialbero1992 do you have plan to work on PRE_TRANSFORM?

[giovannialbero1992]

@rahit can it be useful have a PRE_TRANSFORM event? I can try to implement the event in the next weeks or you can do a PR on my fork to add the new event. Let me know.

[XWB]

Closing as no proper fix seems possible.