Dataloader

.gitignore

@@ -1,3 +1,4 @@
+.env
 composer.phar
 composer.lock
 vendor

config/config.php

@@ -17,11 +17,12 @@
         'types'       => 'App\\Http\\GraphQL\\Types',
         'fields'      => 'App\\Http\\GraphQL\\Fields',
         'connections' => 'App\\Http\\GraphQL\\Connections',
+        'dataloaders' => 'App\\Http\\GraphQL\\DataLoaders',
     ],
 
     'cache' => storage_path('lighthouse/cache'),
     'controller' => 'Nuwave\Lighthouse\Support\Http\Controllers\LaravelController@query',
-    'pagination_macro' => 'paginate',
+    'pagination_macro' => 'toConnection',
     'route' => [],
     'model_path' => 'App\\Models',
     'camel_case' => false,

phpunit.xml

@@ -19,6 +19,6 @@
     <php>
         <!-- Strong Password Generator (https://strongpasswordgenerator.com/) -->
         <env name="APP_KEY" value="O4JYm19Y7qXbllmw5zng88a4MlUmW0uq" />
-        <env name="DB_CONNECTION" value="sqlite" />
+        <!-- <env name="DB_CONNECTION" value="sqlite" /> -->
     </php>
 </phpunit>

src/GraphQL.php

@@ -12,6 +12,7 @@
 use Nuwave\Lighthouse\Support\Cache\FileStore;
 use Nuwave\Lighthouse\Schema\Field;
 use Nuwave\Lighthouse\Schema\QueryParser;
+use Nuwave\Lighthouse\Schema\FieldParser;
 use Nuwave\Lighthouse\Schema\SchemaBuilder;
 
 class GraphQL
@@ -158,6 +159,17 @@ public function edge($name, ObjectType $type = null, $fresh = false)
         return $this->schema()->edgeInstance($name, $type, $fresh);
     }
 
+    /**
+     * Extract Data Loader from IoC container.
+     *
+     * @param  string $name
+     * @return \Nuwave\Lighthouse\Support\DataLoader\GraphQLDataLoader
+     */
+    public function dataLoader($name)
+    {
+        return $this->schema()->dataLoaderInstance($name);
+    }
+
     /**
      * Get cursor encoder for connection edge.
      *
@@ -293,4 +305,14 @@ public function parser()
     {
         return new QueryParser($this->schema(), $this->query);
     }
+
+    /**
+     * Resolve instance of field parser.
+     *
+     * @return \Nuwave\Lighthouse\Schema\FieldParser
+     */
+    public function fieldParser()
+    {
+        return app(FieldParser::class);
+    }
 }

src/LaravelServiceProvider.php

@@ -6,6 +6,7 @@
 use Illuminate\Support\ServiceProvider;
 use Illuminate\Pagination\LengthAwarePaginator;
 use Nuwave\Lighthouse\Support\Traits\GlobalIdTrait;
+use Nuwave\Lighthouse\Support\DataLoader\QueryBuilder;
 
 class LaravelServiceProvider extends ServiceProvider
 {
@@ -90,7 +91,7 @@ protected function registerSchema()
      */
     protected function registerMacro()
     {
-        $name = $this->app['config']->get('lighthouse.pagination_macro') ?: 'paginate';
+        $name = $this->app['config']->get('lighthouse.pagination_macro') ?: 'toConnection';
 
         $decodeCursor = function (array $args) {
             return $this->decodeCursor($args);
@@ -108,5 +109,17 @@ protected function registerMacro()
                 $currentPage
             );
         });
+
+        Collection::macro('fetch', function ($relations) {
+            if (count($this->items) > 0) {
+                if (is_string($relations)) {
+                    $relations = [$relations];
+                }
+
+                $query = $this->first()->newQuery()->with($relations);
+                $this->items = app(QueryBuilder::class)->eagerLoadRelations($query, $this->items);
+            }
+            return $this;
+        });
     }
 }

src/Schema/FieldParser.php

@@ -0,0 +1,81 @@
+<?php
+
+namespace Nuwave\Lighthouse\Schema;
+
+use GraphQL\Language\AST\SelectionSet;
+use GraphQL\Type\Definition\ResolveInfo;
+use GraphQL\Language\AST\Field as GraphQLField;
+use GraphQL\Language\AST\FragmentDefinition;
+use GraphQL\Language\AST\FragmentSpread;
+
+class FieldParser
+{
+    /**
+     * Prefetch data.
+     *
+     * @param  ResolveInfo $info
+     * @param  int $depth
+     * @return void
+     */
+    public function fetch(ResolveInfo $info, $depth = 999999)
+    {
+        $fields = [];
+
+        /** @var GraphQLField $fieldAST */
+        foreach ($info->fieldASTs as $fieldAST) {
+            $fields = array_merge_recursive($fields, $this->foldSelectionSet($fieldAST->selectionSet, $depth));
+        }
+
+        return $fields;
+    }
+
+    /**
+     * Fold field selection set.
+     *
+     * @param  SelectionSet $selectionSet
+     * @param  int          $descend
+     * @return array
+     */
+    protected function foldSelectionSet(SelectionSet $selectionSet, $descend)
+    {
+        $fields = [];
+
+        foreach ($selectionSet->selections as $selectionAST) {
+            if ($selectionAST instanceof GraphQLField) {
+                $fields[$selectionAST->name->value] = $descend > 0 && !empty($selectionAST->selectionSet)
+                    ? $this->buildField($selectionAST, ['children' => $this->foldSelectionSet($selectionAST->selectionSet, $descend - 1)])
+                    : $this->buildField($selectionAST);
+            } else if ($selectionAST instanceof FragmentSpread) {
+                $spreadName = $selectionAST->name->value;
+                if (isset($this->fragments[$spreadName])) {
+                    /** @var FragmentDefinition $fragment */
+                    $fragment = $this->fragments[$spreadName];
+                    $fields += $this->foldSelectionSet($fragment->selectionSet, $descend);
+                }
+            }
+        }
+
+        return $fields;
+    }
+
+    /**
+     * Build field output.
+     *
+     * @param  GraphQLField  $field
+     * @param  array $data
+     * @return array
+     */
+    protected function buildField(GraphQLField $field, $data = [])
+    {
+        $args = [];
+
+        foreach ($field->arguments as $argument) {
+            $args[$argument->name->value] = $argument->value->value;
+        }
+
+        return array_merge([
+            'parent' => isset($data['children']),
+            'args' => $args,
+        ], $data);
+    }
+}

src/Schema/Generators/ConnectionResolveGenerator.php

@@ -31,7 +31,7 @@ public function resolve($root, array $args, $context, ResolveInfo $info, $name)
             return $items;
         }
 
-        return $items->paginate($args);
+        return $items->toConnection($args);
     }
 
     /**

src/Schema/Registrars/DataLoaderRegistrar.php

@@ -0,0 +1,49 @@
+<?php
+
+namespace Nuwave\Lighthouse\Schema\Registrars;
+
+class DataLoaderRegistrar
+{
+    /**
+     * Add Data Loader to registrar.
+     *
+     * @param  string            $name
+     * @param  string $loader
+     * @return bool
+     */
+    public function register($name, $loader)
+    {
+        app()->singleton($loader);
+        app()->alias($loader, $this->alias($name));
+
+        $instance = app($this->alias($name));
+
+        if (empty($instance->getName())) {
+            $instance->setName($name);
+        }
+
+        return true;
+    }
+
+    /**
+     * Extract Data Loader from IoC Container.
+     *
+     * @param  string $name
+     * @return \Nuwave\Lighthouse\Support\DataLoader\GraphQLDataLoader
+     */
+    public function instance($name)
+    {
+        return app($this->alias($name));
+    }
+
+    /**
+     * Get alias of Data Loader.
+     *
+     * @param  string $name
+     * @return string
+     */
+    protected function alias($name)
+    {
+        return 'graphql.dataloader.'.$name;
+    }
+}

src/Schema/SchemaBuilder.php

@@ -156,6 +156,18 @@ public function cursor($name, Closure $encoder, Closure $decoder = null)
         return $this->getCursorRegistrar()->register($name, $encoder, $decoder);
     }
 
+    /**
+     * Add Data Loader to registrar.
+     *
+     * @param  string $name
+     * @param  string $loader
+     * @return bool
+     */
+    public function dataLoader($name, $loader)
+    {
+        return $this->getDataLoaderRegistrar()->register($name, $loader);
+    }
+
     /**
      * Get type field from registrar.
      *
@@ -205,6 +217,17 @@ public function edgeInstance($name, $type = null, $fresh = false)
         return $this->getEdgeRegistrar()->instance($name, $fresh, $type);
     }
 
+    /**
+     * Add Data Loader to registrar.
+     *
+     * @param  string $name
+     * @return \Nuwave\Lighthouse\Support\DataLoader\GraphQLDataLoader
+     */
+    public function dataLoaderInstance($name)
+    {
+        return $this->getDataLoaderRegistrar()->instance($name);
+    }
+
     /**
      * Get encoder for connection edge.
      *

src/Support/Console/Commands/DataLoaderMakeCommand.php

@@ -0,0 +1,75 @@
+<?php
+
+namespace Nuwave\Lighthouse\Support\Console\Commands;
+
+use Illuminate\Console\GeneratorCommand;
+use Symfony\Component\Console\Input\InputOption;
+
+class MutationMakeCommand extends GeneratorCommand
+{
+    /**
+     * The name and signature of the console command.
+     *
+     * @var string
+     */
+    protected $name = 'lighthouse:dataloader';
+
+    /**
+     * The console command description.
+     *
+     * @var string
+     */
+    protected $description = 'Generate a GraphQL DataLoader.';
+
+    /**
+     * The type of class being generated.
+     *
+     * @var string
+     */
+    protected $type = 'DataLoader';
+
+    /**
+     * Get the stub file for the generator.
+     *
+     * @return string
+     */
+    protected function getStub()
+    {
+        return __DIR__.'/stubs/dataloader.stub';
+    }
+
+    /**
+     * Get the default namespace for the class.
+     *
+     * @param  string  $rootNamespace
+     * @return string
+     */
+    protected function getDefaultNamespace($rootNamespace)
+    {
+        return config('lighthouse.namespaces.dataloaders');
+    }
+
+    /**
+     * Get the console command options.
+     *
+     * @return array
+     */
+    protected function getOptions()
+    {
+        return [];
+    }
+
+    /**
+     * Replace the class name for the given stub.
+     *
+     * @param  string  $stub
+     * @param  string  $name
+     * @return string
+     */
+    protected function replaceClass($stub, $name)
+    {
+        $class = str_replace($this->getNamespace($name).'\\', '', $name);
+
+        return str_replace('DummyClass', $class, $stub);
+    }
+}

src/Support/Console/Commands/stubs/dataloader.stub

@@ -0,0 +1,25 @@
+<?php
+
+namespace DummyNamespace;
+
+use Nuwave\Lighthouse\Support\DataLoader\GraphQLDataLoader;
+
+class DummyClass extends GraphQLDataLoader
+{
+    /**
+     * Available fields and associated DataLoaders.
+     *
+     * @var array
+     */
+    protected $children = [];
+
+    /**
+     * Create new instance of DataLoader.
+     *
+     * @return void
+     */
+    public function __construct()
+    {
+        // ...
+    }
+}