Class: GraphQL::Pagination::Connections

Inherits:
Object
  • Object
show all
Defined in:
lib/graphql/pagination/connections.rb

Overview

A schema-level connection wrapper manager.

Attach as a plugin.

Examples:

Adding a custom wrapper

class MySchema < GraphQL::Schema
  connections.add(MyApp::SearchResults, MyApp::SearchResultsConnection)
end

Removing default connection support for arrays (they can still be manually wrapped)

class MySchema < GraphQL::Schema
  connections.delete(Array)
end

See Also:

  • {Schema{Schema.connections}

Defined Under Namespace

Classes: ImplementationMissingError

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(schema:) ⇒ Connections

Returns a new instance of Connections.


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# File 'lib/graphql/pagination/connections.rb', line 31

def initialize(schema:)
  @schema = schema
  @wrappers = {}
  add_default
end

Class Method Details

.use(schema_defn) ⇒ Object


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# File 'lib/graphql/pagination/connections.rb', line 24

def self.use(schema_defn)
  if schema_defn.plugins.any? { |(plugin, args)| plugin == self }
    GraphQL::Deprecation.warn("#{self} is now the default, remove `use #{self}` from #{caller(2,1).first}")
  end
  schema_defn.connections = self.new(schema: schema_defn)
end

Instance Method Details

#add(nodes_class, implementation) ⇒ Object


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# File 'lib/graphql/pagination/connections.rb', line 37

def add(nodes_class, implementation)
  @wrappers[nodes_class] = implementation
end

#all_wrappersObject


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# File 'lib/graphql/pagination/connections.rb', line 45

def all_wrappers
  all_wrappers = {}
  @schema.ancestors.reverse_each do |schema_class|
    if schema_class.respond_to?(:connections) && (c = schema_class.connections)
      all_wrappers.merge!(c.wrappers)
    end
  end
  all_wrappers
end

#delete(nodes_class) ⇒ Object


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# File 'lib/graphql/pagination/connections.rb', line 41

def delete(nodes_class)
  @wrappers.delete(nodes_class)
end

#edge_class_for_field(field) ⇒ Object

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

use an override if there is one


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# File 'lib/graphql/pagination/connections.rb', line 113

def edge_class_for_field(field)
  conn_type = field.type.unwrap
  conn_type_edge_type = conn_type.respond_to?(:edge_class) && conn_type.edge_class
  if conn_type_edge_type && conn_type_edge_type != Relay::Edge
    conn_type_edge_type
  else
    nil
  end
end

#wrap(field, parent, items, arguments, context) ⇒ Object

Used by the runtime to wrap values in connection wrappers.


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# File 'lib/graphql/pagination/connections.rb', line 68

def wrap(field, parent, items, arguments, context)
  return items if GraphQL::Execution::Interpreter::RawValue === items
  wrappers = context ? context.namespace(:connections)[:all_wrappers] : all_wrappers
  impl = wrapper_for(items, wrappers: wrappers)

  if impl
    impl.new(
      items,
      context: context,
      parent: parent,
      field: field,
      max_page_size: field.has_max_page_size? ? field.max_page_size : context.schema.default_max_page_size,
      first: arguments[:first],
      after: arguments[:after],
      last: arguments[:last],
      before: arguments[:before],
      arguments: arguments,
      edge_class: edge_class_for_field(field),
    )
  else
    begin
      connection_class = GraphQL::Relay::BaseConnection.connection_for_nodes(items)
      if parent.is_a?(GraphQL::Schema::Object)
        parent = parent.object
      end
      connection_class.new(
        items,
        arguments,
        field: field,
        max_page_size: field.max_page_size,
        parent: parent,
        context: context,
      )
    rescue RuntimeError => err
      if err.message.include?("No connection implementation to wrap")
        raise ImplementationMissingError, "Couldn't find a connection wrapper for #{items.class} during #{field.path} (#{items.inspect})"
      else
        raise err
      end
    end
  end
end

#wrapper_for(items, wrappers: all_wrappers) ⇒ Object


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# File 'lib/graphql/pagination/connections.rb', line 55

def wrapper_for(items, wrappers: all_wrappers)
  impl = nil

  items.class.ancestors.each { |cls|
    impl = wrappers[cls]
    break if impl
  }

  impl
end