https://github.com/d12/graphql-remote_loader

Performant remote GraphQL queries from within the resolvers of a Ruby GraphQL API.
https://github.com/d12/graphql-remote_loader

graphql graphql-ruby graphql-server ruby ruby-gem schema-stitching

Last synced: about 2 months ago
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Performant remote GraphQL queries from within the resolvers of a Ruby GraphQL API.

• Host: GitHub
• URL: https://github.com/d12/graphql-remote_loader
• Owner: d12
• Created: 2018-06-09T01:28:36.000Z (over 6 years ago)
• Default Branch: master
• Last Pushed: 2020-09-14T14:55:38.000Z (over 4 years ago)
• Last Synced: 2024-09-23T11:37:57.340Z (3 months ago)
• Topics: graphql, graphql-ruby, graphql-server, ruby, ruby-gem, schema-stitching
• Language: Ruby
• Homepage:
• Size: 86.9 KB
• Stars: 51
• Watchers: 1
• Forks: 1
• Open Issues: 7
• Metadata Files:
  • Readme: README.md

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README

        
# GraphQL Remote Loader

[![Gem Version](https://badge.fury.io/rb/graphql-remote_loader.svg)](https://badge.fury.io/rb/graphql-remote_loader) [![Build Status](https://travis-ci.org/d12/graphql-remote_loader.svg?branch=master)](https://travis-ci.org/d12/graphql-remote_loader)

Performant, batched GraphQL queries from within the resolvers of a [`graphql-ruby`](https://github.com/rmosolgo/graphql-ruby) API.

## Snippet

```ruby

field :login, String, null: false, description: "The currently authenticated GitHub user's login."

def login

  GitHubLoader.load("viewer { login }").then do |results|

    if results["errors"].present?

      ""

    else

      results["data"]["viewer"]["login"].upcase

    end

  end

end

```

## Description

`graphql-remote_loader` allows for querying GraphQL APIs from within resolvers of a [`graphql-ruby`](https://github.com/rmosolgo/graphql-ruby) API. 

This can be used to create GraphQL APIs that depend on data from other GraphQL APIs, either remote or local.

A promise-based resolution strategy from Shopify's [`graphql-batch`](https://github.com/Shopify/graphql-batch) is used to batch all requested data into a single GraphQL query. Promises are fulfilled with only the data they requested.

You can think of it as a lightweight version of schema-stitching.

## Performance

Each `Loader#load` invocation does not send a GraphQL query to the remote. The Gem uses graphql-batch to collect all GraphQL queries together, then combines them and sends a single query to the upstream. The gem splits the response JSON up so that each promise is only resolved with data that it asked for.

## How to use

First, you'll need to install the gem. Either do `gem install graphql-remote_loader` or add this to your Gemfile:

```

gem "graphql-remote_loader"

```

The gem provides a base loader `GraphQL::RemoteLoader::Loader` which does most of the heavy lifting. In order to remain client-agnostic, there's an unimplemented no-op that takes a query string and queries the remote GraphQL API.

To use, create a new class that inherits from `GraphQL::RemoteLoader::Loader` and define `def query(query_string)`. The method takes a query String as input. The expected output is a response `Hash`, or an object that responds to `#to_h`.

Example:

```ruby

require "graphql/remote_loader"

module MyApp

  class GitHubLoader < GraphQL::RemoteLoader::Loader

    def query(query_string)

      parsed_query = GraphQLClient.parse(query_string)

      GraphQLClient.query(parsed_query)

    end

  end

end

```

This example uses [`graphql-client`](https://github.com/github/graphql-client). Any client, or even just plain `cURL`/`HTTP` can be used.

With your loader setup, you can begin using `#load` or `#load_value` in your `graphql-ruby` resolvers.

## Full example

To see a working example of how `graphql-remote_loader` works, see the [complete, working example application](https://github.com/d12/graphql-remote_loader_example).

## Running tests

```

bundle install

bundle exec rspec

```