Arguments.md

Arguments

This example serves as a simple tutorial on how to declare and use arguments on fields.

Introduction

In this example, we define a simple schema with a few arguments and execute one request on it. You should be familiar with our previous HelloWorld example to understand the basics.

Define our types

Here we define one Query object type with few arguments on fields.

<?php

declare(strict_types = 1);

namespace Example;

final class Query extends \Graphpinator\Typesystem\Type
{
    protected const NAME = 'Query';
    protected const DESCRIPTION = 'Graphpinator Arguments: Query type';

    public function validateNonNullValue($rawValue) : bool
    {
        return true;
    }

    protected function getFieldDefinition() : \Graphpinator\Typesystem\Field\ResolvableFieldSet
    {
        return new \Graphpinator\Typesystem\Field\ResolvableFieldSet([
            \Graphpinator\Typesystem\Field\ResolvableField::create(
                'print',
                \Graphpinator\Typesystem\Container::String()->notNull(),
                function ($parent, string $arg) : string {
                    return $arg;
                },
            )->setArguments(
                new \Graphpinator\Typesystem\Argument\ArgumentSet([
                    \Graphpinator\Typesystem\Argument\Argument::create(
                        'arg',
                        \Graphpinator\Typesystem\Container::String()->notNull(),
                    ),            
                ])
            ),
            \Graphpinator\Typesystem\Field\ResolvableField::create(
                'sum',
                \Graphpinator\Typesystem\Container::Int()->notNull(),
                function ($parent, int $arg1, int $arg2) : int {
                    return $arg1 + $arg2;
                },
            )->setArguments(
                new \Graphpinator\Typesystem\Argument\ArgumentSet([
                    \Graphpinator\Typesystem\Argument\Argument::create(
                        'arg1',
                        \Graphpinator\Typesystem\Container::Int()->notNull(),
                    ),
                    \Graphpinator\Typesystem\Argument\Argument::create(
                        'arg2',
                        \Graphpinator\Typesystem\Container::Int()->notNull(),
                    )->setDefaultValue(0),              
                ])
            ),
        ]);
    }
}

As you can see, declaring arguments is really simple - it is the fourth parameter in ResolvableField and third in Field, which is used in interfaces.

Optional step - print schema definition

Visualise our GraphQL schema in type language.

Declaration of Container, Schema and Graphpinator classes is skipped in this example. Visit our HelloWorld example for more information.

Printing the schema using infinityloop-dev/graphpinator-printer produces following schema.

schema {
  query: Query
  mutation: null
  subscription: null
}

"""
Graphpinator Arguments: Query type
"""
type Query {
  print(
    arg: String!
  ): String!
  sum(
    arg1: Int!
    arg2: Int! = 0
  ): Int!
}

Execute Request

$json = \Infinityloop\Utils\Json::fromString(
    '{"query":"query { print(arg: "Hello world!") }"}'
);
$requestFactory = new \Graphpinator\Request\JsonRequestFactory($json);
$response = $graphpinator->run($requestFactory);

This is it, we have our response in $response variable. The query above will produce:

{"data":{"print": "Hello world!"}}

Example using the sum endpoint:

$json = \Infinityloop\Utils\Json::fromString(
    '{"query":"query { sum(arg1: 10) }"}'
);
$requestFactory = new \Graphpinator\Request\JsonRequestFactory($json);
$response = $graphpinator->run($requestFactory);

will produce

{"data":{"sum": 10}}

Congratulations

This is the end of the Arguments example, thank you for reading this far.

• For more information visit the complete Docs.
• For more examples visit the examples folder.