Class: GraphQL::Stitching::Client

Inherits:
Object
  • Object
show all
Defined in:
lib/graphql/stitching/client.rb

Overview

Client is an out-of-the-box helper that assembles all stitching components into a workflow that executes requests.

Defined Under Namespace

Classes: ClientError

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(locations: nil, supergraph: nil, composer: nil) ⇒ Client

Builds a new client instance. Either supergraph or locations configuration is required.

Parameters:

  • supergraph (Supergraph) (defaults to: nil) —

    optional, a pre-composed supergraph that bypasses composer setup.

  • locations (Hash<Symbol, Hash<Symbol, untyped>>) (defaults to: nil) —

    optional, composer configurations for each graph location.

  • composer (Composer) (defaults to: nil) —

    optional, a pre-configured composer instance for use with locations configuration.



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# File 'lib/graphql/stitching/client.rb', line 19

def initialize(locations: nil, supergraph: nil, composer: nil)
  @supergraph = if locations && supergraph
    raise ClientError, "Cannot provide both locations and a supergraph."
  elsif supergraph && !supergraph.is_a?(Supergraph)
    raise ClientError, "Provided supergraph must be a GraphQL::Stitching::Supergraph instance."
  elsif supergraph
    supergraph
  else
    composer ||= Composer.new
    composer.perform(locations)
  end

  @on_cache_read = nil
  @on_cache_write = nil
  @on_error = nil
end

Instance Attribute Details

#supergraph ⇒ Supergraph (readonly)

Returns composed supergraph that services incoming requests.

Returns:

  • (Supergraph) —

    composed supergraph that services incoming requests.



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# File 'lib/graphql/stitching/client.rb', line 13

def supergraph
  @supergraph
end

Instance Method Details

#execute(raw_query = nil, query: nil, variables: nil, operation_name: nil, context: nil, validate: true) ⇒ Object 



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# File 'lib/graphql/stitching/client.rb', line 36

def execute(raw_query = nil, query: nil, variables: nil, operation_name: nil, context: nil, validate: true)
  request = Request.new(
    @supergraph,
    raw_query || query, # << for parity with GraphQL Ruby Schema.execute
    operation_name: operation_name,
    variables: variables,
    context: context,
  )

  if validate
    validation_errors = request.validate
    return error_result(request, validation_errors) if validation_errors.any?
  end

  request.prepare!
  load_plan(request)
  request.execute
rescue GraphQL::ParseError, GraphQL::ExecutionError => e
  error_result(request, [e])
rescue StandardError => e
  custom_message = @on_error.call(request, e) if @on_error
  error_result(request, [{ "message" => custom_message || "An unexpected error occured." }])
end

#on_cache_read(&block) ⇒ Object

Raises:



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# File 'lib/graphql/stitching/client.rb', line 60

def on_cache_read(&block)
  raise ClientError, "A cache read block is required." unless block_given?
  @on_cache_read = block
end

#on_cache_write(&block) ⇒ Object

Raises:



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# File 'lib/graphql/stitching/client.rb', line 65

def on_cache_write(&block)
  raise ClientError, "A cache write block is required." unless block_given?
  @on_cache_write = block
end

#on_error(&block) ⇒ Object

Raises:



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# File 'lib/graphql/stitching/client.rb', line 70

def on_error(&block)
  raise ClientError, "An error handler block is required." unless block_given?
  @on_error = block
end