Type mapping

As explained in the queries section, the job of GraphQLite is to create GraphQL types from PHP types.

Scalar mapping

Scalar PHP types can be type-hinted to the corresponding GraphQL types:

• string
• int
• bool
• float

For instance:

namespace App\Controller;

use TheCodingMachine\GraphQLite\Annotations\Query;

class MyController
{
    /**
     * @Query
     */
    public function hello(string $name): string
    {
        return 'Hello ' . $name;
    }
}

Class mapping

When returning a PHP class in a query, you must annotate this class using @Type and @Field annotations:

namespace App\Entities;

use TheCodingMachine\GraphQLite\Annotations\Field;
use TheCodingMachine\GraphQLite\Annotations\Type;

/**
 * @Type()
 */
class Product
{
    // ...

    /**
     * @Field()
     */
    public function getName(): string
    {
        return $this->name;
    }

    /**
     * @Field()
     */
    public function getPrice(): ?float
    {
        return $this->price;
    }
}

Array mapping

You can type-hint against arrays (or iterators) as long as you add a detailed @return statement in the PHPDoc.

/**
 * @Query
 * @return User[] <=== we specify that the array is an array of User objects.
 */
public function users(int $limit, int $offset): array
{
    // Some code that returns an array of "users".
}

ID mapping

GraphQL comes with a native ID type. PHP has no such type.

There are two ways with GraphQLite to handle such type.

Force the outputType

/**
 * @Field(outputType="ID")
 */
public function getId(): string
{
    // ...
}

Using the outputType attribute of the @Field annotation, you can force the output type to ID.

You can learn more about forcing output types in the custom output types section.

ID class

use TheCodingMachine\GraphQLite\Types\ID;

/**
 * @Field
 */
public function getId(): ID
{
    // ...
}

Note that you can also use the ID class as an input type:

use TheCodingMachine\GraphQLite\Types\ID;

/**
 * @Mutation
 */
public function save(ID $id, string $name): Product
{
    // ...
}

Date mapping

Out of the box, GraphQL does not have a DateTime type, but we took the liberty to add one, with sensible defaults.

When used as an output type, DateTimeImmutable or DateTimeInterface PHP classes are automatically mapped to this DateTime GraphQL type.

/**
 * @Field
 */
public function getDate(): \DateTimeInterface
{
    return $this->date;
}

The date field will be of type DateTime. In the returned JSON response to a query, the date is formatted as a string in the ISO8601 format (aka ATOM format).

PHP DateTime type is not supported.

Union types

You can create a GraphQL union type on the fly using the pipe | operator in the PHPDoc:

/**
 * @Query
 * @return Company|Contact <== can return a company OR a contact.
 */
public function companyOrContact(int $id)
{
    // Some code that returns a company or a contact.
}