Unions

A Union is an abstract type that holds other object types. When passed as type to a field, it means that the field can return any of the types held by the union.

php-graphql represents unions as instances of the class GraphQLUnion, which accepts several parameters in the constructor for configuring the union.

use GraphQL\Types\GraphQLUnion;

$SearchResultType = new GraphQLUnion(
    "SearchResult", 
    "Type of data being returned by a search query", 
    [
        &$bookType, 
        &$authorType
    ]
);

GraphQLUnion Constructor

Parameters used for the GraphQLUnion constructors are (in the following order):