Provides a DSL for the graphql
gem that allows ActiveRecord associations to be preloaded in field definitions. Based on a gist by @theorygeek.
Add this line to your application's Gemfile:
gem 'graphql-preload'
And then execute:
$ bundle
Or install it yourself as:
$ gem install graphql-preload
First, enable preloading in your GraphQL::Schema
:
Schema = GraphQL::Schema.define do
use GraphQL::Batch
enable_preloading
end
Call preload
when defining your field:
PostType = GraphQL::ObjectType.define do
name 'Post'
field :comments, !types[!CommentType] do
# Post.includes(:comments)
preload :comments
# Post.includes(:comments, :authors)
preload [:comments, :authors]
# Post.includes(:comments, authors: [:followers, :posts])
preload [:comments, { authors: [:followers, :posts] }]
resolve ->(obj, args, ctx) { obj.comments }
end
end
Starting with Rails 4.1, you can scope your preloaded records by passing a valid scope to ActiveRecord::Associations::Preloader
. Scoping can improve performance by reducing the number of models to be instantiated and can help with certain business goals (e.g., only returning records that have not been soft deleted).
This functionality is surfaced through the preload_scope
option:
PostType = GraphQL::ObjectType.define do
name 'Post'
field :comments, !types[!CommentType] do
preload :comments
preload_scope ->(args, ctx) { Comment.where(deleted_at: nil) }
# Resolves with records returned from the following query:
# SELECT "comments".*
# FROM "comments"
# WHERE "comments"."deleted_at" IS NULL
# AND "comments"."post_id" IN (1, 2, 3)
resolve ->(obj, args, ctx) { obj.comments }
end
end
After checking out the repo, run bin/setup
to install dependencies. Then, run rake test
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 tags, and push the .gem
file to rubygems.org.
Bug reports and pull requests are welcome on GitHub at https://github.com/ConsultingMD/graphql-preload.
The gem is available as open source under the terms of the MIT License.
Releases happen in CircleCI when a tag is pushed to the repository.
To create a release, you will need to do the following:
- Change the version in
lib/graphql/preload/version.rb
to the new version and create a PR with the change. - Once the PR is merged, switch to the master branch and
git pull
. git tag <version from version.rb>
git push origin --tags
CircleCI will see the tag push, build, and release a new version of the library.