shish/gqla

A set of annotations for generating graphql APIs

v1.0.0 2024-02-25 14:48 UTC

This package is auto-updated.

Last update: 2024-04-26 21:36:38 UTC


README

A GraphQL schema generator based on PHP Attributes

Because when your webapp already has objects for internal use, you shoudn't need to rewrite or duplicate everything in order to query those objects via graphql :)

The schemas generated here are based on https://github.com/webonyx/graphql-php, so once you've generated a schema, look at the docs over there for how to make use of it

Example:

use GQLA\Type;
use GQLA\Field;
use GQLA\Query;
use GQLA\Mutation;

// To create a new GraphQL Type, expose a PHP class
#[Type]
class Post {
    // To add fields to that type, expose PHP class properties
    #[Field]
    public string $title;
    #[Field]
    public string $body;

    // If you don't want the field to be part of your API,
    // don't expose it
    public int $author_id;

    // If your field is more complicated than a property,
    // expose a PHP function and it will be called as needed
    #[Field(name: "author")]
    public function get_author(): User {
        return User::by_id($this->author_id);
    }

    // To add a new query or mutation, you can extend
    // the base Query or Mutation types
    #[Query(name: "posts", type: "[Post!]!")]
    public static function search_posts(string $text): array {
        // SELECT * FROM posts WHERE text LIKE "%{$text}%";
    }
}

#[Type]
class User {
    #[Field]
    public string $name;
}

#[Type]
class Comment {
    #[Field]
    public string $text;
    public int $post_id;
    public int $author_id;
    #[Field]
    public function author(): User {
        return User::by_id($this->author_id);
    }
    #[Field(deprecationReason: "Use author subfield")]
    public function author_name(): string {
        return User::by_id($this->author_id)->name;
    }

    // Note that even if the Comment class comes from a third-party
    // plugin, it can still add a new "comments" field onto the
    // first-party "Post" object type.
    #[Field(extends: "Post", type: "[Comment!]!")]
    public function comments(Post $post): array {
        // SELECT * FROM comments WHERE post_id = {$post->id}
    }
}

Then new \GQLA\Schema(); will search for all annotated objects and return a graphql schema like:

type Post {
    title: String!
    body: String!
    author: User!
    comments: [Comment!]!
}

type User {
    name: String!
}

type Comment {
    text: String!
    author: User!
    author_name: String @deprecated(reason: "Use author subfield")
}

type Query {
    search_posts(text: String!): [Post!]!
}

So you can send a query like

{
    search_posts(text: "Hello") {
        title
        body
        author {
            name
        }
        comments {
            text
        }
    }
}

And get a response like

{
    "data": {
        "posts": [
            {
                "title": "Hello world!",
                "body": "This is the first post in my blog",
                "author": {
                    "name": "Shish",
                },
                "comments": [
                    { "text": "Nice first post!" },
                    { "text": "It works :D" },
                ],
            }
        ]
    }
}

API

These annotations have several common parameters:

  • name: Give a specific name to this type / field (default: Use the class / property / function name)
  • type: Give a specific type to the field (default: infer this from the PHP-types-to-GraphQL-types map)
    • Note that if your PHP type is array, then you must specify type with something more specific for GraphQL, for example:
      #[Field(type: "[String!]!")]
      function get_tags(): array {
          return ["foo", "bar"];
      }
  • args: Override the inferred types for any function arguments
    • As with type, note that this is required whenever a PHP function accepts an array as input, for example:
      #[Field(args: ["tags" => "[String!]!"])]
      function get_first_post_with_tags(array $tags): Post {
          return ...;
      }
  • extends: By default, an exposed field on an exposed object will be added as a field of that object. You can also extend your other objects (eg, a "likes" plugin could add a number_of_likes field onto your BlogPost object)
  • description: Add a description to your GraphQL schema for anybody who wants to develop client apps
  • deprecationReason: Mark this field as deprecated