graphql-wp
A GraphQL endpoint for WordPress that's easy to customize.
This is a WordPress Plugin that exposes a GraphQL endpoint at /graphql.
Uses this excellent graphql-php library.
Supports Relay Connections.
Install
composer require mohiohio/graphql-wp
If your aren't familiar with using composer with WordPress I'd recommend using a setup like bedrock. Otherwise you will at the least need to require autoload.php for this to work.
Using
The best way to explore / develop with this is by visiting /graphiql after installation. This will show you the endpoints and arguments that are available. Note this will only work if you are a logged in admin user.
wp_query
This is designed to follow WordPress' existing WP Query functions. So as a rule you can pass the same parameters as your can to WP Query*.
*In reality there are a lot of params you can pass to WP_Query, and I've only implemented the ones that I've needed so far. But adding more is trivial as the arguments are just passed directly to the get_posts function, so its just a matter of defining them in the schema.
query example {
wp_query {
posts(first: 10) {
edges {
node {
title
name
terms(taxonomy: "category") {
name
slug
}
}
}
}
}
}Will give you
{
"data": {
"wp_query": {
"posts": {
"edges": [
{
"node": {
"title": "Dashboard",
"name": "hello-world",
"terms": [
{
"name": "Uncategorized",
"slug": "uncategorized"
}
]
}
}
]
}
}
}
}Post
And of course you can get an individual post
query example {
wp_post(ID: 9) {
title
content
status
}
}Custom Fields
Any meta fields are available like so
query example {
wp_post(ID: 9) {
title
foo: meta_value(key: "foo")
bar: meta_value(key: "bar")
}
}If you want to define your own resolver / type you can extend the field schema for a post type like so.
// There is a get_{post_type}_schema call available for each post type
add_filter('graphql-wp/get_post_schema', function($schema) {
$schema['fields'] = function() use ($schema) {
// Note call to "parent" function here
return $schema['fields']() + [
'foo' => [
'type' => Type::string(),
'resolve' => function($post) {
return get_post_meta($post->ID, 'foo' ,true);
}
],
'bar' => [
'type' => Type::string(),
'resolve' => function($post) {
return get_post_meta($post->ID, 'bar' ,true);
}
]
];
};
return $schema;
});Custom Post Types
This is how you can add custom post types ( which have custom fields ) to a client specific plugin.
graphql-wp/get_post_types is a good hook for this.
Where $types is a hash of the schema we are working with, so just add new items into this and you are good to go.
use GraphQL\Type\Definition\Type;
use Mohiohio\GraphQLWP\Type\Definition\Post;
use Mohiohio\GraphQLWP\Type\Definition\Attachment;
class Foo extends Post {
static function getDescription() {
return "A custom post type example, for post type `foo`";
}
static function getFieldSchema() {
return parent::getFieldSchema() + [
'website' => [
'type' => Type::string(),
'resolve' => function($post) {
return get_post_meta($post->ID,'website',true);
},
],
'image' => [
'type' => Attachment::getInstance(),
'resolve' => function($post) {
$attachment_id = get_post_meta($post->ID,'image',true);
return $attachment_id ? get_post($attachment_id) : null;
},
]
];
}
}
add_filter('graphql-wp/schema-types', function($types){
return array_merge($types, [
Foo::getInstance()
]);
});