README

Doctrine Helper to import from / export to JSON object graphs

Uses Symfony's PropertyAccess to convert objects to arrays or generate objects from arrays. Which classes & properties can be exported/imported (and how) can be controlled with the ExportableProperty and ImportableProperty PHP attributes: Only classes that have at least one ExportableProperty can be converted to array, only classes that have at least one ImportableProperty can be instantiated from array. Uses Doctrines ClassUtils to safely handle proxies.

Usage

Short Example, for more details see ExportEntity / ImportEntity and ExportHelperTest / ImportHelperTest for all features. Allows to export referenced entities (or only their identifiers) and collections.

use Vrok\ImportExport\ExportableProperty;
use Vrok\ImportExport\ExportHelper;
use Vrok\ImportExport\ImportableProperty;
use Vrok\ImportExport\ImportHelper;

class Entity
{
    #[ExportableProperty]
    #[ImportableProperty]
    public int $id = 0;

    #[ExportableProperty]
    #[ImportableProperty]
    public ?\DateTimeImmutable $timestamp = null;
}

$entity = new Entity();
$entity->id = 1;
$entity->timestamp = new \DateTimeImmutable();

$helper = new ExportHelper();
$export = $helper->objectToArray($entity);
$exportList = $helper->collectionToArray([$entity]);

/*
  $export === [
    'id'        => 1,
    'timestamp' => '2022-03-23....',
  ]
*/

$helper = new ImportHelper();
$newInstance = $helper->objectFromArray($export, Entity::class);
$newInstances = $helper->collectionFromArray([$export], Entity::class);

Features

Export

• can output object graphs, if a property pointing to another entity or DTO is marked with ExportableProperty
• can export an identifier, to be later mapped to the actual record, by using the referenceByIdentifier argument of the ExportableProperty attribute, e.g. instead of exporting the whole User, only it's ID could be exported for the createdBy property of another record.
• can export collections of objects (either by using collectionToArray or when a property is a Doctrine Collection or an array and marked with asList), even when they are of different types (e.g. through inheritance). An _entityClass field will contain the actual class.
• can limit exported data to only allowed properties by using the propertyFilter argument of fromArray
• can prevent (otherwise exportable property) from being exported by using the propertyFilter argument of fromArray and setting isExcludeFilter to true

Import

• can reference existing records: if a property (collection or single object) points to an "importable entity" and the dataset contains an int/string the given ObjectManager is used to fetch the specified record from the database
• handle object graphs:

  {
    "name": "base entity",
    "nested": {
      "description": "for a property with type hint",
      "child": {
        "value": "for a property that is e.g. typed as an Interface",
        "_entityClass": "\\My\\DtoClass"
      } 
    }
  }

• import only permitted fields (even when the dataset contains more, potentially importable properties) by using the propertyFilter argument of fromArray
• exclude fields from importing (even when they are in the dataset and potentially importable) by using the propertyFilter argument of fromArray and setting isExcludeFilter to true
• automatically persist generated

Dependencies

• doctrine/common for the ClassUtils (proxy handling) and Collection properties
• doctrine/persistence for the ObjectManager (importing references)
• symfony/property-access for setting/reading (private, protected) properties

Future Improvements

• what could be done with Symfony's serializer?
  • can already transform object (graphs) to array
  • properties can be marked with groups to be exportable
  • how to mark properties to only be exported as identifier? new attribute? how implement that, how is APIP doing this?
  • how to mark array properties to be treated as DTO-List?
  • how to ignore some properties without the need to hardcode groups? (exclude-filter)
  • how to limit to some properties without the need to hardcode groups? (include-filter)
• evaluate Doctrine's ORM collection attributes to check for allowed element class
• Improve union type handling (e.g. multiple base types: int|string)
• not only export to arrays but also directly to files
  • support exporting to multiple files (split to reduce size for large datasets)
• not only import from arrays but also directly from JSON files
  • support importing from multiple files (have been split to reduce size)