GraphQL Type System Definition to a config yaml

[mcg-web]

Add a feature that convert GraphQL Type System Definition:

interface Character {
  id: String!
  name: String
  friends: [Character]
  appearsIn: [Episode]
}

to config yaml file:

Character:
    type: interface
    config:
        fields:
            id:
                type: "String!"
            name:
                type: "String"
            friends:
                type: "[Character]"
            appearsIn:
                type: "[Episode]"

[akomm]

Do you want it as an alternative to yml config, or separate - lets say command - to generate the yml out of schema definition?

[mcg-web]

hi @akomm,
the need has change since... Now that webonyx/graphql-php supports Type System Definition to schema natively, graphql definition we be an easy way to write the schema. This solution will be more reusable than yaml, xml or php definition...

[enumag]

I think I might have found a work-around...

First define a SchemaFactory:

<?php declare(strict_types = 1);

namespace App\GraphQL;

use GraphQL\Type\Schema;
use GraphQL\Utils\BuildSchema;

class SchemaFactory
{
	public static function create(string $rootDir): Schema
	{
		// TODO: Add caching according to http://webonyx.github.io/graphql-php/type-system/type-language/#performance-considerations
		$contents = file_get_contents($rootDir . '/config/graphql/types/schema.graphql');

		return BuildSchema::build($contents);
	}
}

Then register the schema in services.yml:

    overblog_graphql.schema_default:
        factory: 'App\GraphQL\SchemaFactory:create'
        arguments:
            - %kernel.project_dir%

And add the schema.graphql file:

schema {
    query: Query
}

type Query {
    greetings(input: HelloInput!): String!
}

input HelloInput {
    firstName: String!
    lastName: String
}

What I don't understand however is how to define the resolver needed for the greetings query to work. Currently it throws this error:

Cannot return null for non-nullable field Query.greetings.

I know why, I didn't define anywhere how the greetings query should respond after all so it returns null. But how do I fix it?

[mcg-web]

That all the difficulty of using graphQL schema language because it is a backend and frontend language so it is not allowing any server information like resolvers. Executor.RootValue variable can help you inject resolvers like callable. But doing so, you loose all the benefits of using this bundle, I highly recommends you using yaml and dump command to generate the schema for frontends... Or just directly using the webonyx lib.