Class: GraphitiGraphQL::Federation::SchemaDecorator

Inherits:
Object
  • Object
show all
Defined in:
lib/graphiti_graphql/federation/schema_decorator.rb

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(schema) ⇒ SchemaDecorator

Returns a new instance of SchemaDecorator.



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# File 'lib/graphiti_graphql/federation/schema_decorator.rb', line 8

def initialize(schema)
  @schema = schema
end

Class Method Details

.decorate(schema) ⇒ Object 



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# File 'lib/graphiti_graphql/federation/schema_decorator.rb', line 4

def self.decorate(schema)
  new(schema).decorate
end

Instance Method Details

#add_federated_resource_interface(federated_resource) ⇒ Object 



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# File 'lib/graphiti_graphql/federation/schema_decorator.rb', line 79

def add_federated_resource_interface(federated_resource)
  interface = define_polymorphic_federated_resource_interface(federated_resource.klass_name)
  federated_resource.type_name.values.each do |name|
    add_federated_resource_type(name, interface: interface)
  end
  interface
end

#add_federated_resource_type(klass_name, interface: nil) ⇒ Object 



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# File 'lib/graphiti_graphql/federation/schema_decorator.rb', line 96

def add_federated_resource_type(klass_name, interface: nil)
  federated_type = Class.new(@schema.class.base_object)
  federated_type.graphql_name klass_name
  federated_type.key(fields: "id")
  federated_type.extend_type
  federated_type.implements(interface) if interface
  federated_type.field :id, String, null: false, external: true
  federated_type.class_eval do
    def self.resolve_reference(reference, _context, _lookup)
      reference
    end
  end
  # NB must be registered before processing relationships
  type_registry[klass_name] = {type: federated_type}
  federated_type
end

#add_federated_resources ⇒ Object 



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# File 'lib/graphiti_graphql/federation/schema_decorator.rb', line 51

def add_federated_resources
  each_federated_resource do |type_class, federated_resource|
    federated_resource.relationships.each_pair do |name, relationship|
      if relationship.has_many?
        define_federated_has_many(type_class, relationship)
      elsif relationship.belongs_to?
        define_federated_belongs_to(federated_resource, relationship)
      end
    end
  end
end

#add_resolve_reference ⇒ Object

Add to all local resource types This is if a remote federated resource belongs_to a local resource



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# File 'lib/graphiti_graphql/federation/schema_decorator.rb', line 22

def add_resolve_reference
  @schema.type_registry.each_pair do |name, config|
    if config[:resource]
      local_type = config[:type]
      local_type.key(fields: "id") if local_type.respond_to?(:key)
      local_resource = Graphiti.resources
        .find { |r| r.name == config[:resource] }
      # TODO: maybe turn off the graphiti debug for these?
      local_type.define_singleton_method :resolve_reference do |reference, context, lookahead|
        Federation::Loaders::BelongsTo
          .for(local_resource, lookahead.selections.map(&:name))
          .load(reference[:id])
      end
    end
  end
end

#decorate ⇒ Object 



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# File 'lib/graphiti_graphql/federation/schema_decorator.rb', line 12

def decorate
  @schema.schema.send(:include, ApolloFederation::Schema)
  # NB if we add mutation support, make sure this is applied after
  @schema.schema.use(GraphQL::Batch)
  add_resolve_reference
  add_federated_resources
end

#define_connection_type(name, type_class) ⇒ Object 



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# File 'lib/graphiti_graphql/federation/schema_decorator.rb', line 113

def define_connection_type(name, type_class)
  name = "#{name}FederatedConnection"
  if (registered = type_registry[name])
    return registered[:type]
  end

  klass = Class.new(@schema.class.base_object)
  klass.graphql_name(name)
  klass.field :nodes,
    [type_class],
    null: false,
    extras: [:lookahead]
  @schema.send :register, name, klass
  klass
end

#define_federated_belongs_to(federated_resource, relationship) ⇒ Object 



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# File 'lib/graphiti_graphql/federation/schema_decorator.rb', line 169

def define_federated_belongs_to(federated_resource, relationship)
  type_name = GraphitiSchema::Resource.gql_name(relationship.local_resource_class.name)
  local_type = type_registry[type_name][:type]

  # Todo maybe better way here
  interface = type_registry["I#{type_name}"]

  local_type = interface[:type] if interface
  local_types = [local_type]
  if interface
    local_types |= interface[:implementers]
  end

  local_types.each do |local|
    local.field relationship.name,
      type_registry[federated_resource.klass_name][:type],
      null: true
  end
end

#define_federated_has_many(type_class, relationship) ⇒ Object 



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# File 'lib/graphiti_graphql/federation/schema_decorator.rb', line 129

def define_federated_has_many(type_class, relationship)
  local_name = GraphitiGraphQL::GraphitiSchema::Resource
    .gql_name(relationship.local_resource_class.name)
  local_type = type_registry[local_name][:type]
  local_resource_name = type_registry[local_name][:resource]
  local_resource = Graphiti.resources.find { |r| r.name == local_resource_name }

  local_interface = type_registry["I#{local_name}"]
  best_type = local_interface ? local_interface[:type] : local_type

  connection_type = define_connection_type(local_name, best_type)

  field = type_class.field relationship.name,
    connection_type,
    null: false,
    connection: false
  @schema.send :define_arguments_for_sideload_field,
    field, @schema.graphiti_schema.get_resource(local_resource_name)

  type_class.define_method relationship.name do |**arguments|
    {data: object, arguments: arguments}
  end
  connection_type.define_method :nodes do |lookahead:, **arguments|
    params = object[:arguments].as_json
      .deep_transform_keys { |key| key.to_s.underscore.to_sym }
    selections = lookahead.selections.map(&:name)
    selections << relationship.foreign_key
    selections << :_type # polymorphism
    params[:fields] = {local_resource.type => selections.join(",")}

    if (sort = Util.parse_sort(params[:sort]))
      params[:sort] = sort
    end

    Federation::Loaders::HasMany
      .for(relationship, params)
      .load(object[:data][:id])
  end
end

#define_polymorphic_federated_resource_interface(klass_name) ⇒ Object 



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# File 'lib/graphiti_graphql/federation/schema_decorator.rb', line 87

def define_polymorphic_federated_resource_interface(klass_name)
  interface = Module.new
  interface.send(:include, @schema.class.base_interface)
  interface.graphql_name(klass_name)
  interface.field :id, String, null: false, external: true
  type_registry[klass_name] = {type: interface, interface: true}
  interface
end

#each_federated_resource ⇒ Object

NB: test already registered bc 2 things have same relationship



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# File 'lib/graphiti_graphql/federation/schema_decorator.rb', line 64

def each_federated_resource
  federated_resources.each do |federated_resource|
    pre_registered = !!type_registry[federated_resource.type_name]
    type_class = if pre_registered
      type_registry[federated_resource.type_name][:type]
    elsif federated_resource.polymorphic?
      add_federated_resource_interface(federated_resource)
    else
      add_federated_resource_type(federated_resource.klass_name)
    end

    yield type_class, federated_resource
  end
end

#federated_resources ⇒ Object 



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# File 'lib/graphiti_graphql/federation/schema_decorator.rb', line 39

def federated_resources
  federated = []
  Graphiti.resources.each do |r|
    federated |= (r.config[:federated_resources] || [])
  end
  federated
end

#type_registry ⇒ Object 



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# File 'lib/graphiti_graphql/federation/schema_decorator.rb', line 47

def type_registry
  @schema.type_registry
end