graphql-functions

Ruby gem made to simplify the standard query creation of the graphql gem in your Active Record models with predefined functions.

Using the provided functions your graphql types will gain standard and generic query arguments to limit the amount of rows, use an offset, or filter by an specific id among others; supporting queries like the following:

{
  people(limit: 2) {
    id,
    first_name
  }  
}

{
  people(ids: [1, 4, 9]) {
    id,
    age
  }
}

{
  person(id: 3) {
    id,
    last_name
  }
}

The full list of features is shown here.

Add this line to your application's Gemfile:

gem 'graphql-functions'

And then execute:

$ bundle

Or install it yourself as:

$ gem install graphql-functions

Please note that you should also have installed the base graphql gem.

First of all you have to honor the following files structure convention:

app\
--controllers\
--models\
----person.rb
--graphql\
----types\
------query_type.rb
------person_type.rb
----mutations\
----functions\
------person.rb
------people.rb
----schema.rb

To help getting started is useful to use the graphql generator.

Then you should create a class inside the functions folder subclassing of the two provided functions to the query type definition:

# app/graphql/functions/people.rb
module Functions
  class People < GraphQL::Functions::Array
    model ::Person
    argument :country_code, types.String

    # optional custom logic code.
    # 'relation' represent the data filtered by the built-in array arguments (limit, offset, etc)
    def query(relation, obj, args, ctx)
      relation.where(country_code: args[:countryCode]) if args[:countryCode]
    end
  end
end

# app/graphql/functions/person.rb

module Functions
  class Person < GraphQL::Functions::Element
    model ::Person
  end
end

# app/graphql/types/query_type.rb
module Types
  QueryType = GraphQL::ObjectType.define do
    name "Query"

    field :person, function: Functions::Person.create
    field :people, function: Functions::People.create
  end
end

Above changes will in addition to the base query capabilities from graphql-functions allow the query to filter by countryCode in the people field like:

{
  people(countryCode: 'us', limit: 2, offset: 5) {
    id,
    first_name,
    last_name
  }
}

Element function is intended to be used with a query with a single field output like person in the example: The only available argument is id:

• id: Int Filter by the specified id.

If id is not specified or if the subclass implements its own query method which does not return a single element, the first element of the model is returned.

Array function add filters-like arguments to the query:

• offset: Int Skip the specified argument of records.
• limit: Int Do not return more rows than the argument.
• ids: [Int] Filter by the specified ids.
• order_by: String Order by the specified argument.
• desc: Boolean Flag to order descending.

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 tags, and push the .gem file to rubygems.org.

Bug reports and pull requests are welcome on GitHub at https://github.com/comparaonline/graphql-functions.

The gem is available as open source under the terms of the MIT License.