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

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 24

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

Instance Method Details

#add(nodes_class, implementation) ⇒ Object 



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# File 'lib/graphql/pagination/connections.rb', line 30

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

#all_wrappers ⇒ Object 



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# File 'lib/graphql/pagination/connections.rb', line 38

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 34

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 88

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 != Pagination::Connection::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 61

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,
      default_page_size: field.has_default_page_size? ? field.default_page_size : context.schema.default_page_size,
      first: arguments[:first],
      after: arguments[:after],
      last: arguments[:last],
      before: arguments[:before],
      arguments: arguments,
      edge_class: edge_class_for_field(field),
    )
  else
    raise ImplementationMissingError, "Couldn't find a connection wrapper for #{items.class} during #{field.path} (#{items.inspect})"
  end
end

#wrapper_for(items, wrappers: all_wrappers) ⇒ Object 



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# File 'lib/graphql/pagination/connections.rb', line 48

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

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

  impl
end