Allow using instance of Field

CHANGELOG.md

@@ -3,6 +3,8 @@ CHANGELOG
 
 [Next release](https://github.com/rebing/graphql-laravel/compare/3.1.0...master)
 --------------
+### Added
+- Allow passing through an instance of a `Field` [\#521 / georgeboot](https://github.com/rebing/graphql-laravel/pull/521/files)
 ### Fixed
 - Fix validation rules for non-null list of non-null objects [\#511 / crissi](https://github.com/rebing/graphql-laravel/pull/511/files)
 - Add morph type to returned models [\#503 / crissi](https://github.com/rebing/graphql-laravel/pull/503)

Readme.md

@@ -7,7 +7,7 @@
 [![License](https://poser.pugx.org/rebing/graphql-laravel/license)](https://packagist.org/packages/rebing/graphql-laravel)
 [![Get on Slack](https://img.shields.io/badge/slack-join-orange.svg)](https://join.slack.com/t/rebing-graphql/shared_invite/enQtNTE5NjQzNDI5MzQ4LWVjMTMxNzIyZjBlNTFhZGQ5MDVjZDAwZDNjODA3ODE2NjdiOGJkMjMwMTZkZmNhZjhiYTE1MjEyNDk0MWJmMzk)
 
-### Note: these are the docs for 2.*, [please see the `v1` branch for the 1.* docs](https://github.com/rebing/graphql-laravel/tree/v1#laravel-graphql)
+### Note: these are the docs for the current release, [please see the `v1` branch for the 1.* docs](https://github.com/rebing/graphql-laravel/tree/v1#laravel-graphql)
 
 Uses Facebook GraphQL with Laravel 5.5+. It is based on the PHP implementation [here](https://github.com/webonyx/graphql-php). You can find more information about GraphQL in the [GraphQL Introduction](http://facebook.github.io/react/blog/2015/05/01/graphql-introduction.html) on the [React](http://facebook.github.io/react) blog or you can read the [GraphQL specifications](https://facebook.github.io/graphql/). This is a work in progress.
 
@@ -101,31 +101,44 @@ To work this around:
 
 ## Usage
 
-- [Schemas](#schemas)
-- [Creating a query](#creating-a-query)
-- [Creating a mutation](#creating-a-mutation)
-- [Adding validation to mutation](#adding-validation-to-mutation)
-- [File uploads](#file-uploads)
-- [Authorization](#authorization)
-- [Privacy](#privacy)
-- [Query variables](#query-variables)
-- [Custom field](#custom-field)
-- [Eager loading relationships](#eager-loading-relationships)
-- [Type relationship query](#type-relationship-query)
-- [Pagination](#pagination)
-- [Batching](#batching)
-- [Scalar Types](#scalar-types)
-- [Enums](#enums)
-- [Unions](#unions)
-- [Interfaces](#interfaces)
-- [Input Object](#input-object)
-- [JSON Columns](#json-columns)
-- [Field deprecation](#field-deprecation)
-- [Default Field Resolver](#default-field-resolver)
-- [Upgrading from v1 to v2](#upgrading-from-v1-to-v2)
-- [Migrating from Folklore](#migrating-from-folklore)
-- [Performance considerations](#performance-considerations)
-- [Wrap Types](#wrap-types)
+- [Laravel GraphQL](#laravel-graphql)
+    - [Note: these are the docs for 3.*, please see the `v1` branch for the 1.* docs](#note-these-are-the-docs-for-3-please-see-the-v1-branch-for-the-1-docs)
+  - [Installation](#installation)
+      - [Dependencies:](#dependencies)
+      - [Installation:](#installation)
+        - [Laravel 5.5+](#laravel-55)
+        - [Lumen (experimental!)](#lumen-experimental)
+  - [Usage](#usage)
+    - [Schemas](#schemas)
+    - [Creating a query](#creating-a-query)
+    - [Creating a mutation](#creating-a-mutation)
+      - [Adding validation to a mutation](#adding-validation-to-a-mutation)
+      - [File uploads](#file-uploads)
+    - [Authorization](#authorization)
+    - [Privacy](#privacy)
+    - [Query Variables](#query-variables)
+    - [Custom field](#custom-field)
+      - [Even better reusable fields](#even-better-reusable-fields)
+    - [Eager loading relationships](#eager-loading-relationships)
+    - [Type relationship query](#type-relationship-query)
+    - [Pagination](#pagination)
+    - [Batching](#batching)
+    - [Scalar Types](#scalar-types)
+    - [Enums](#enums)
+    - [Unions](#unions)
+    - [Interfaces](#interfaces)
+      - [Sharing Interface fields](#sharing-interface-fields)
+    - [Input Object](#input-object)
+    - [JSON Columns](#json-columns)
+      - [Field deprecation](#field-deprecation)
+      - [Default Field Resolver](#default-field-resolver)
+  - [Guides](#guides)
+    - [Upgrading from v1 to v2](#upgrading-from-v1-to-v2)
+    - [Migrating from Folklore](#migrating-from-folklore)
+  - [Performance considerations](#performance-considerations)
+    - [Lazy loading of types](#lazy-loading-of-types)
+      - [Example of aliasing **not** supported by lazy loading](#example-of-aliasing-not-supported-by-lazy-loading)
+    - [Wrap Types](#wrap-types)
 
 ### Schemas
 
@@ -810,7 +823,120 @@ class UserType extends GraphQLType
         ];
     }
 }
+```
+
+#### Even better reusable fields
+
+Instead of using the class name, you can also supply an actual instance of the `Field`. This allows you to not only re-use the field, but will also open up the possibility to re-use the resolver.
+
+Let's imagine we want a field type that can output dates formatted in all sorts of ways.
+
+```php
+<?php
+
+namespace App\GraphQL\Fields;
+
+use GraphQL\Type\Definition\Type;
+use Rebing\GraphQL\Support\Field;
+
+class FormattableDate extends Field
+{        
+    protected $attributes = [
+        'description' => 'A field that can output a date in all sorts of ways.',
+    ];
+
+    public function __construct(array $settings = [])
+    {
+        $this->attributes = \array_merge($this->attributes, $settings);
+    }
+
+    public function type(): Type
+    {
+        return Type::string();
+    }
+
+    public function args(): array
+    {
+        return [
+            'format' => [
+                'type' => Type::string(),
+                'defaultValue' => 'Y-m-d H:i',
+                'description' => 'Defaults to Y-m-d H:i',
+            ],
+            'relative' => [
+                'type' => Type::boolean(),
+                'defaultValue' => false,
+            ],
+        ];
+    }
+
+    protected function resolve($root, $args): ?string
+    {
+        $date = $root->{$this->getProperty()};
+
+        if (!$date instanceof Carbon) {
+            return null;
+        }
+
+        if ($args['relative']) {
+            return $date->diffForHumans();
+        }
+
+        return $date->format($args['format']);
+    }
+
+    protected function getProperty(): string
+    {
+        return $this->attributes['alias'] ?? $this->attributes['name'];
+    }
+}
+```
+
+You can use this field in your type as follows:
+
+```php
+<?php
+
+namespace App\GraphQL\Types;
+
+use App\GraphQL\Fields\FormattableDate;
+use App\User;
+use GraphQL\Type\Definition\Type;
+use Rebing\GraphQL\Support\Type as GraphQLType;
+
+class UserType extends GraphQLType
+{
+    protected $attributes = [
+        'name'          => 'User',
+        'description'   => 'A user',
+        'model'         => User::class,
+    ];
+
+    public function fields(): array
+    {
+        return [
+            'id' => [
+                'type' => Type::nonNull(Type::string()),
+                'description' => 'The id of the user'
+            ],
+            'email' => [
+                'type' => Type::string(),
+                'description' => 'The email of user'
+            ],
+
+            // You can simply supply an instance of the class
+            'dateOfBirth' => new FormattableDate,
 
+            // Because the constructor of `FormattableDate` accepts our the array of parameters,
+            // we can override them very easily.
+            // Imagine we want our field to be called `createdAt`, but our database column 
+            // is called `created_at`:
+            'createdAt' => new FormattableDate([
+                'alias' => 'created_at',
+            ])
+        ];
+    }
+}
 ```
 
 ### Eager loading relationships

src/Support/Field.php

@@ -16,6 +16,9 @@
 use Rebing\GraphQL\Error\ValidationError;
 use Validator;
 
+/**
+ * @property string $name
+ */
 abstract class Field
 {
     protected $attributes = [];

src/Support/Type.php

@@ -39,7 +39,7 @@ public function attributes(): array
     }
 
     /**
-     * @return array<string,array|string|FieldDefinition>
+     * @return array<string,array|string|FieldDefinition|Field>
      */
     public function fields(): array
     {
@@ -89,6 +89,9 @@ public function getFields(): array
                 $field = app($field);
                 $field->name = $name;
                 $allFields[$name] = $field->toArray();
+            } elseif ($field instanceof Field) {
+                $field->name = $name;
+                $allFields[$name] = $field->toArray();
             } elseif ($field instanceof FieldDefinition) {
                 $allFields[$field->name] = $field;
             } else {

tests/Unit/InstantiableTypesTest/FormattableDate.php

@@ -0,0 +1,65 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Rebing\GraphQL\Tests\Unit\InstantiableTypesTest;
+
+use Carbon\Carbon;
+use GraphQL\Type\Definition\Type;
+use Rebing\GraphQL\Support\Field;
+
+class FormattableDate extends Field
+{
+    protected $attributes = [
+        'description' => 'A field that can format dates in all sorts of ways.',
+    ];
+
+    protected $defaultFormat;
+
+    public function __construct(array $settings = [], string $defaultFormat = 'Y-m-d H:i')
+    {
+        $this->attributes = \array_merge($this->attributes, $settings);
+
+        $this->defaultFormat = $defaultFormat;
+    }
+
+    public function args(): array
+    {
+        return [
+            'format' => [
+                'type' => Type::string(),
+                'defaultValue' => $this->defaultFormat,
+                'description' => \sprintf('Defaults to %s', $this->defaultFormat),
+            ],
+            'relative' => [
+                'type' => Type::boolean(),
+                'defaultValue' => false,
+            ],
+        ];
+    }
+
+    public function type(): Type
+    {
+        return Type::string();
+    }
+
+    public function resolve($root, array $args): ?string
+    {
+        $date = $root->{$this->getProperty()};
+
+        if (! $date instanceof Carbon) {
+            return null;
+        }
+
+        if ($args['relative']) {
+            return $date->diffForHumans();
+        }
+
+        return $date->format($args['format']);
+    }
+
+    protected function getProperty(): string
+    {
+        return $this->attributes['alias'] ?? $this->attributes['name'];
+    }
+}

tests/Unit/InstantiableTypesTest/InstantiableTypesTest.php

@@ -0,0 +1,56 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Rebing\GraphQL\Tests\Unit\InstantiableTypesTest;
+
+use Carbon\Carbon;
+use Rebing\GraphQL\Tests\TestCase;
+
+class InstantiableTypesTest extends TestCase
+{
+    public function testSomething(): void
+    {
+        $query = <<<'GRAQPHQL'
+{
+    user {
+        default: dateOfBirth,
+        formattedDifferent: dateOfBirth(format: "Y-m-d"),
+        relative: dateOfBirth(relative: true),
+        alias: createdAt
+    }
+}
+GRAQPHQL;
+
+        $result = $this->graphql($query);
+
+        $dateOfBirth = Carbon::now()->addMonth()->startOfDay();
+        $createdAt = Carbon::now()->startOfDay();
+
+        $expectedResult = [
+            'data' => [
+                'user' => [
+                    'default' => $dateOfBirth->format('Y-m-d H:i'),
+                    'formattedDifferent' => $dateOfBirth->format('Y-m-d'),
+                    'relative' => '4 weeks from now',
+                    'alias' => $createdAt->format('Y-m-d H:i'),
+                ],
+            ],
+        ];
+        $this->assertSame($expectedResult, $result);
+    }
+
+    protected function getEnvironmentSetUp($app)
+    {
+        parent::getEnvironmentSetUp($app);
+
+        $app['config']->set('graphql.schemas.default', [
+            'query' => [
+                'user' => UserQuery::class,
+            ],
+        ]);
+        $app['config']->set('graphql.types', [
+            'UserType' => UserType::class,
+        ]);
+    }
+}

tests/Unit/InstantiableTypesTest/UserQuery.php

@@ -0,0 +1,36 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Rebing\GraphQL\Tests\Unit\InstantiableTypesTest;
+
+use Carbon\Carbon;
+use GraphQL\Type\Definition\Type;
+use Rebing\GraphQL\Support\Facades\GraphQL;
+use Rebing\GraphQL\Support\Query;
+
+class UserQuery extends Query
+{
+    protected $attributes = [
+        'name' => 'postMessages',
+    ];
+
+    public function type(): Type
+    {
+        return GraphQL::type('UserType');
+    }
+
+    public function args(): array
+    {
+        return [];
+    }
+
+    public function resolve($root, $args)
+    {
+        return (object) [
+            'id' => 1,
+            'dateOfBirth' => Carbon::now()->addMonth()->startOfDay(),
+            'created_at' => Carbon::now()->startOfDay(),
+        ];
+    }
+}