Types

Both GraphQL and Doctrine ORM have their own type systems. Most of the primitive types can be associated one to another. Like Doctrine columns type string can be mapped to GraphQL String type, also Doctrine integer, smallint, and bigint all can be mapped with GraphQL Int type.

In this sense, it is possible to map a Doctrine's entity class as GraphQL ObjectType and its properties having primitive type to GraphQL's ScalarType.

Naming convention

Cool, since we already know that this is possible then we need to make some conventions on how to map the entity class to GraphQL named type. But there's a catch here, since graphql schema doesn't support namespace we need a way to merge all doctrine entity classes into a single collection.

DoctrineGraphQL currently take the easiest way to do that, replace all the \ character from the entity fully qualified class name. For example, supposed that we have an entity Vendor\Package\Enity\User in the generated GraphQL schema the entity type will be named VendorPackageEntityUser.

The primitive type mapping between Doctrine types to GraphQL shown on table below.

Doctrine Type	GraphQL Type
string	String
text	String
integer	Int
smallint	Int
bigint	Int
boolean	Boolean
decimal	float
float	float
guid	String
date	DateTime
time	DateTime
datetime	DateTime
datetimetz	DateTime
object	-
array	-
simple_array	-
json_array	-
blob	-

That's pretty neat, but how about associations of Doctrine entities (one-to-many, many-to-many, many-to-one and one-to-one)? Well, since GraphQL was essentially a collection of 'instructions' on how to fetch data and re-present it as a graph structure. We can map all those associations in two distinct type, list of objects (one-to-many, many-to-many) amd and single object (many-to-one, one-to-one).

The only problem is we first need populate all Doctrine entities as GraphQL named ObjectType and then we add the associations fields on every defined ObjectType based of the entity association configuration. DoctrineGraphQL already handle this for you.

Custom naming strategy

If the default strategy is not suitable, we can always implement our own naming strategy by creating a class that implements LLA\DoctrineGraphQL\EntityTypeNameGenerator interface. Then we can pass the naming generator instance to the factory class constructor.

use LLA\DoctrineGraphQL\EntityTypeNameGenerator;

class MyGraphqlTypeNameGenerator implements EntityTypeNameGenerator
{
    /**
     * {@inheritdoc}
     */
    public function generate(string $classname): string
    {
        // returns a graphql type name for specified $classname
    }
}

use LLA\DoctrineGraphQL\DoctrineGraphQL;

$nameGenerator = MyGraphqlTypeNameGenerator();
$factory = new DoctrineGraphQL($nameGenerator);

Built in types

DoctrineGraphQL also comes with other built-in types.

DateTime

This type is not GraphQL standard type. DateTime time is mapped with Doctrine type date, time, datetime and datetimetz. All those doctrine type will be formatted as as ISO8601 datetime string, and any input using this type must also be ISO8601 formatted.