class GraphQL::Schema::Printer

Used to convert your GraphQL::Schema to a GraphQL schema string

Examples

Example: print your schema to standard output (via helper)

puts GraphQL::Schema::Printer.print_schema(MySchema)

Example: print your schema to standard output

puts GraphQL::Schema::Printer.new(MySchema).print_schema

Example: print a single type to standard output

class Types::Query < GraphQL::Schema::Object
  description "The query root of this schema"

  field :post, Types::Post, null: true
end

class Types::Post < GraphQL::Schema::Object
  description "A blog post"

  field :id, ID, null: false
  field :title, String, null: false
  field :body, String, null: false
end

class MySchema < GraphQL::Schema
  query(Types::Query)
end

printer = GraphQL::Schema::Printer.new(MySchema)
puts printer.print_type(Types::Post)

Attributes

schema [R]

warden [R]

Public Class Methods

initialize(GraphQL::Schema schema, Hash context:, bool introspection:)

Source

# File lib/graphql/schema/printer.rb, line 56
def initialize(schema, context: nil, introspection: false)
  @document_from_schema = GraphQL::Language::DocumentFromSchemaDefinition.new(
    schema,
    context: context,
    include_introspection_types: introspection,
  )

  @document = @document_from_schema.document
  @schema = schema
end

Parameters

schema (GraphQL::Schema)
context (Hash)
introspection (Boolean) — Should include the introspection types in the string?

print_introspection_schema ()

Source

# File lib/graphql/schema/printer.rb, line 68
def self.print_introspection_schema
  query_root = Class.new(GraphQL::Schema::Object) do
    graphql_name "Root"
    field :throwaway_field, String
    # Not `def self.visible?`: Sorbet would treat it as a definition of `Printer.visible?`
    define_singleton_method(:visible?) { |ctx| false }
  end
  schema = Class.new(GraphQL::Schema) {
    query(query_root)
    use GraphQL::Schema::Visibility
    def self.visible?(member, _ctx)
      member.graphql_name != "Root"
    end
  }

  introspection_schema_ast = GraphQL::Language::DocumentFromSchemaDefinition.new(
    schema,
    include_introspection_types: true,
    include_built_in_directives: true,
  ).document

  introspection_schema_ast.to_query_string(printer: IntrospectionPrinter.new)
end

Return the GraphQL schema string for the introspection type system

print_schema(GraphQL::Schema schema, **args)

Source

# File lib/graphql/schema/printer.rb, line 103
def self.print_schema(schema, **args)
  printer = new(schema, **args)
  printer.print_schema
end

Return a GraphQL schema string for the defined types in the schema

Parameters

schema (GraphQL::Schema)
context (Hash)
only (<#call(member, ctx)>)
except (<#call(member, ctx)>)

Public Instance Methods

print_schema ()

Source

# File lib/graphql/schema/printer.rb, line 109
def print_schema
  print(@document) + "\n"
end

Return a GraphQL schema string for the defined types in the schema

print_type (type)

Source

# File lib/graphql/schema/printer.rb, line 113
def print_type(type)
  node = @document_from_schema.build_type_definition_node(type)
  print(node)
end