Mastering GraphQL Mutations with the graphql-client Ruby Gem

GraphQL has become a popular choice for building APIs due to its flexibility and efficiency. When working with GraphQL APIs in Ruby, the graphql-client gem proves to be a powerful tool. In this article, we will delve into the intricacies of using mutations with the graphql-client gem to modify data on the server side.

Introduction to GraphQL Mutations

In GraphQL, mutations are operations used to modify data on the server. While queries are used to fetch data, mutations enable us to create, update, or delete data. This distinction aligns with the principles of the GraphQL schema, where mutations are defined to perform write operations.

Setting Up the graphql-client Gem

Before diving into mutations, it’s crucial to have the graphql-client gem set up in your Ruby project. The gem facilitates easy communication with GraphQL APIs. Here is a basic setup snippet:

require 'graphql/client'
require 'graphql/client/http'

module Api
  HTTP = GraphQL::Client::HTTP.new(ENV['GRAPHQL_API_URL'])
  Schema = GraphQL::Client.load_schema(HTTP)
  Client = GraphQL::Client.new(schema: Schema, execute: HTTP)
end

Make sure to replace 'GRAPHQL_API_URL' it with the actual URL of your GraphQL endpoint.

Executing a Mutation

Executing a mutation with the graphql-client gem is similar to querying data. Let's take an example of a mutation that creates a country. In this case, we have a mutation called CreateCountryMutation:

CreateCountryMutation = Api::Client.parse(<<~'GRAPHQL')   
  mutation($name: String) {
    createCountry(name: $name) {
      id
    }
  }
GRAPHQL

This mutation expects a parameter name of type String and returns the ID of the created city.

To execute this mutation, you can use the following code snippet:

variables = { name: 'United States' }
result = Api::Client.query(CreateCountryMutation, variables: variables)


puts result.data.create_country.id

Replace 'United States' with the desired country name. The result object will contain the response from the server, and you can access the created country's ID using result.data.create_country.id.

Conclusion

The graphql-client gem simplifies the process of working with GraphQL APIs in Ruby, and mutations play a crucial role in modifying data. By understanding how to structure mutations and execute them using the graphql-client gem, you can seamlessly integrate write operations into your Ruby applications.

Explore more about GraphQL mutations, handle errors, and optimize your mutations for efficient data manipulation. The combination of GraphQL and the graphql-client gem opens up a world of possibilities for building robust and flexible APIs. Happy coding!