created relay middleware trait

Author: chrissm79

src/Context.php

@@ -0,0 +1,143 @@
+<?php
+
+namespace Nuwave\Relay;
+
+use GraphQL\Executor\Executor;
+use GraphQL\Error;
+use GraphQL\Language\AST\Document;
+use GraphQL\Language\AST\Field;
+use GraphQL\Language\AST\FragmentDefinition;
+use GraphQL\Language\AST\Node;
+use GraphQL\Language\AST\OperationDefinition;
+use GraphQL\Language\AST\SelectionSet;
+use GraphQL\Schema;
+use GraphQL\Type\Definition\AbstractType;
+use GraphQL\Type\Definition\Directive;
+use GraphQL\Type\Definition\EnumType;
+use GraphQL\Type\Definition\FieldDefinition;
+use GraphQL\Type\Definition\InterfaceType;
+use GraphQL\Type\Definition\ListOfType;
+use GraphQL\Type\Definition\NonNull;
+use GraphQL\Type\Definition\ObjectType;
+use GraphQL\Type\Definition\ResolveInfo;
+use GraphQL\Type\Definition\ScalarType;
+use GraphQL\Type\Definition\Type;
+use GraphQL\Type\Definition\UnionType;
+use GraphQL\Type\Introspection;
+use GraphQL\Utils;
+use GraphQL\Language\Parser;
+use GraphQL\Language\Source;
+use GraphQL\Validator\DocumentValidator;
+use GraphQL\Executor\ExecutionResult;
+use GraphQL\Executor\Values;
+use GraphQL\Executor\ExecutionContext;
+
+class Context extends Executor
+{
+    private static $UNDEFINED;
+
+    /**
+     * Constructs a ExecutionContext object from the arguments passed to
+     * execute.
+     *
+     * (https://github.com/webonyx/graphql-php/blob/master/src/Executor/Executor.php)
+     *
+     * @param  Schema $schema         [description]
+     * @param  $requestString
+     * @param  $rootValue
+     * @param  $variableValues
+     * @param  $operationName
+     * @return ExecutionContext
+     */
+    public static function get(Schema $schema, $requestString, $rootValue = null, $variableValues = null, $operationName = null)
+    {
+        try {
+            $source = new Source($requestString ?: '', 'GraphQL request');
+            $documentAST = Parser::parse($source);
+            $validationErrors = DocumentValidator::validate($schema, $documentAST);
+
+            if (!empty($validationErrors)) {
+                return null;
+            } else {
+                return self::generate($schema, $documentAST, $rootValue, $variableValues, $operationName);
+            }
+        } catch (Error $e) {
+            return null;
+        }
+    }
+
+    /**
+     * @param  Schema   $schema
+     * @param  Document $ast
+     * @param  $rootValue
+     * @param  $variableValues
+     * @param  $operationName
+     * @return ExecutionContext
+     */
+    protected static function generate(Schema $schema, Document $ast, $rootValue = null, $variableValues = null, $operationName = null)
+    {
+        if (!self::$UNDEFINED) {
+            self::$UNDEFINED = new \stdClass();
+        }
+
+        if (null !== $variableValues) {
+            Utils::invariant(
+                is_array($variableValues) || $variableValues instanceof \ArrayAccess,
+                "Variable values are expected to be array or instance of ArrayAccess, got " . Utils::getVariableType($variableValues)
+            );
+        }
+
+        if (null !== $operationName) {
+            Utils::invariant(
+                is_string($operationName),
+                "Operation name is supposed to be string, got " . Utils::getVariableType($operationName)
+            );
+        }
+
+        return self::buildExecutionContext($schema, $ast, $rootValue, $variableValues, $operationName);
+    }
+
+    /**
+     * @param  Schema   $schema
+     * @param  Document $documentAst
+     * @param  $rootValue
+     * @param  $rawVariableValues
+     * @param  $operationName
+     * @return ExecutionContext
+     */
+    protected static function buildExecutionContext(Schema $schema, Document $documentAst, $rootValue, $rawVariableValues, $operationName = null)
+    {
+        $errors = [];
+        $operations = [];
+        $fragments = [];
+
+        foreach ($documentAst->definitions as $statement) {
+            switch ($statement->kind) {
+                case Node::OPERATION_DEFINITION:
+                    $operations[$statement->name ? $statement->name->value : ''] = $statement;
+                    break;
+                case Node::FRAGMENT_DEFINITION:
+                    $fragments[$statement->name->value] = $statement;
+                    break;
+            }
+        }
+
+        if (!$operationName && count($operations) !== 1) {
+            throw new Error(
+                'Must provide operation name if query contains multiple operations.'
+            );
+        }
+
+        $opName = $operationName ?: key($operations);
+
+        if (empty($operations[$opName])) {
+            throw new Error('Unknown operation named ' . $opName);
+        }
+
+        $operation = $operations[$opName];
+        $variableValues = Values::getVariableValues($schema, $operation->variableDefinitions ?: [], $rawVariableValues ?: []);
+        $exeContext = new ExecutionContext($schema, $fragments, $rootValue, $operation, $variableValues, $errors);
+
+        return $exeContext;
+    }
+}

src/Traits/RelayMiddleware.php

@@ -0,0 +1,57 @@
+<?php
+
+namespace Nuwave\Relay\Traits;
+
+use Illuminate\Http\Request;
+use Nuwave\Relay\Context;
+
+trait RelayMiddleware
+{
+    /**
+     * Middleware to be attached to GraphQL query.
+     *
+     * @var array
+     */
+    protected $relayMiddleware = [];
+
+    /**
+     * Genarate middleware to be run on query.
+     *
+     * @param  Request $request
+     * @return array
+     */
+    public function queryMiddleware(Request $request)
+    {
+        $relay  = app('relay');
+        $schema = app('graphql')->schema();
+        $query  = $request->get('query');
+        $params = $request->get('variables');
+
+        if (is_string($params)) {
+            $params = json_decode($params, true);
+        }
+
+        $context      = Context::get($schema, $query, null, $params);
+        $operation    = $context->operation->operation;
+        $selectionSet = $context->operation->selectionSet->selections;
+
+        foreach ($selectionSet as $selection) {
+            if (is_object($selection) && $selection instanceof \GraphQL\Language\AST\Field) {
+                try {
+                    $schema = $relay->find(
+                        $selection->name->value,
+                        $context->operation->operation
+                    );
+
+                    if (isset($schema['middleware']) && !empty($schema['middleware'])) {
+                        $this->relayMiddleware = array_merge($this->relayMiddleware, $schema['middleware']);
+                    }
+                } catch (\Exception $e) {
+                    continue;
+                }
+            }
+        }
+
+        return array_unique($this->relayMiddleware);
+    }
+}