Union Type Definition
A Union is an abstract type that simply enumerates other Object Types. Value of Union Type is actually a value of one of included Object Types.
In graphql-php union type is an instance of GraphQL\Type\Definition\UnionType
(or one of it subclasses) which accepts configuration array in constructor:
$searchResultType = new UnionType([
'name' => 'SearchResult',
'types' => [
MyTypes::story(),
MyTypes::user()
];
'resolveType' => function($value) {
if ($value->type === 'story') {
return MyTypes::story();
} else {
return MyTypes::user();
}
}
]);
This example uses inline style for Union definition, but you can also use
inheritance.
Configuration options
Constructor of UnionType accepts an array. Below is a full list of allowed options:
Option | Type | Notes |
---|---|---|
name | string |
Required. Unique name of this interface type within Schema |
types | array |
Required. List of Object Types included in this Union. Note that you can't create a Union type out of Interfaces or other Unions. |
description | string |
Plain-text description of this type for clients (e.g. used by GraphiQL for auto-generated documentation) |
resolveType | callback returning instance of ObjectType |
function($value, $context, GraphQL\Type\Definition\ResolveInfo $info) Any callable that receives $value from resolver of the parent field and returns Object Type for that $value . |