Class: GraphQL::Sources::ActiveRecordCollection

Inherits:
ActiveRecordBase
  • Object
show all
Defined in:
lib/graphql/sources/active_record_collection.rb

Overview

A class for loading ‘has_many` style associations.

class User
  has_many :comments
end

class Comment
  belongs_to :user
end

class UserType < GraphQL::Schema::Object
  field :comments, [CommentType], null: false

  def comments
    dataloader
      .with(GraphQL::Sources::ActiveRecordCollection, ::Comment, key: :user_id)
      .load(object.id)
  end
end

The resulting SQL query is:

SELECT "comments".*
FROM "comments"
WHERE "comments"."user_id" IN (...)
ORDER BY "comments"."id"

Instance Method Summary collapse

Methods inherited from ActiveRecordBase

batch_key_for, #initialize

Constructor Details

This class inherits a constructor from GraphQL::Sources::ActiveRecordBase

Instance Method Details

#fetch(keys) ⇒ Array

Returns grouped records mirroring the keys.

Parameters:

  • keys (Array) —

    an array of keys

Returns:

  • (Array) —

    grouped records mirroring the keys



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# File 'lib/graphql/sources/active_record_collection.rb', line 34

def fetch(keys)
  models = models(keys: keys).order(:id).load_async
  dataloader.yield

  map = models.group_by { |model| model[@key] }
  keys.map { |key| map[key] || [] }
end