graphql-dataloader-activerecord

This gem provides proxy objects in place of ActiveRecord objects where the proxy handles relationship loading through GraphQL::Dataloader. This is an experimental approach which should theoretically allow authors to write GraphQL code that relies on ActiveRecord using regular ActiveRecord relationship methods without generating N+1 query situations.

By including DataloaderRelationProxy::Lazy, your ActiveRecord-based type classes can transparently use efficient Dataloaders. For example, in the following example, N stories, and their authors can be authorized and loaded in a constant number of queries without changing the implementation of the types:

class Query < GraphQL::Schema::Object
  field :stories, ['Types::Story']

  def stories
    ::Story.all
  end
end

class Story < GraphQL::Schema::Object
  include DataloaderRelationProxy::Lazy

  field :author, Types::User
  field :text, String

  def self.authorized?(object, context)
    # Even though it looks like we're loading the author here, object.author is
    # actually spawning a new fiber and yielding back to the GraphQL engine.
    # The return value is also chainable so we can continue to efficiently follow
    # ActiveRecord relationships as shown:
    return false unless object.author.plan.name == 'paid'

    # Arbitrary rule to force publication to load to demonstrate this
    # functionality
    return object.publication.present?
  end

  # There is no need to define an `author` method here since @object responds
  # to `author` already, but if we did, it would be:
  def author
    @object.author
  end
end

After checking out the repo, run bin/setup to install dependencies. Then, run rake spec to run the tests. You can also run bin/console for an interactive prompt that will allow you to experiment.

To install this gem onto your local machine, run bundle exec rake install. To release a new version, update the version number in version.rb, and then run bundle exec rake release, which will create a git tag for the version, push git commits and the created tag, and push the .gem file to rubygems.org.

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Then create a new pull request through the github interface

Copyright (c) 2022 Dropbox, Inc.

Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at

http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.