Overview

Query execution is a complex process involving multiple steps, including query parsing, validating and finally executing against your schema.

graphql-php provides convenient facade for this process in class GraphQL\GraphQL:

use GraphQL\GraphQL;

$result = GraphQL::execute(
    $schema, 
    $queryString, 
    $rootValue = null, 
    $contextValue = null, 
    $variableValues = null, 
    $operationName = null
);

Method returns array with data and errors keys, as described by GraphQL specs. This array is suitable for further serialization (e.g. using json_encode). See also section on error handling.

Description of method arguments:

Argument	Type	Notes
schema	GraphQL\Schema	Required. Instance of your application Schema
queryString	string or GraphQL\Language\AST\Document	Required. Actual GraphQL query string to be parsed, validated and executed. If you parse query elsewhere before executing - pass corresponding ast document here to avoid new parsing.
rootValue	mixed	Any value that represents a root of your data graph. It is passed as 1st argument to field resolvers of Query type. Can be omitted or set to null if actual root values are fetched by Query type itself.
contextValue	mixed	Any value that holds information shared between all field resolvers. Most often they use it to pass currently logged in user, locale details, etc. It will be available as 3rd argument in all field resolvers. (see section on Field Definitions for reference) graphql-php never modifies this value and passes it as is to all underlying resolvers.
variableValues	array	Map of variable values passed along with query string. See section on query variables on official GraphQL website
operationName	string	Allows the caller to specify which operation in queryString will be run, in cases where queryString contains multiple top-level operations.

Parsing

Following reading describes implementation details of query execution process. It may clarify some internals of GraphQL but is not required in order to use it. Feel free to skip to next section on Error Handling for essentials.

TODOC

Validating

TODOC

Executing

TODOC