GraphQL 10% Project

Dustin McCraw

6/6/18

Api's and Client's

Written code for:

Apiv3

McFeely

Dozer

League Frontend

NextJenn

Rosetta

Erlond

I have seen all the challenges of writing both backend and clients

REST Api

Representational state transfer

Define "resources" with CRUD actions

Disadvantages with multiple clients:

• Overfetching
• Multiple calls for associated resources
• Create custom endpoints for different client needs

GraphQL

• GraphQL is a query language created at Facebook in 2012
• Open source way to define an API
• Standard way to provide the description of the data of your api and it lets clients request exactly what they need
• Came from the conflict between users' wanting to get all the information in one query vs the requirement to isolated REST calls

GraphQL

Advantages

• Retrieve only the data you need on consumer side
• Reduce the data volume returned by the server because you retrieve only what you need
• Reduce the number of calls to retrieve data by linking resources and aggregating queries
• Discover the schema you are querying

GraphQL

https://githubengineering.com/the-github-graphql-api/

Title Text

• Defines a data shape
• Hierarchical/Graph
• Strongly typed
• Protocol
• Introspective

Define Shape

Queries mirror their response.

The clients determine what data they need.

Hierarchical/Graph/Relational

GraphQL defines the relationships between the objects.

Clients can choose what relationships they need for their specific use case.

Strongly Typed

Each level of a query corresponds to a type. Each type has a set of available fields.

Define a Schema using scalar types

A Character has a non null name and a non null list of Episodes.

Schema takes care of all validation

Protocol

Open source standard between server and clients

Can be written in any backend language using any datastore.

Introspective

Query for the types it supports

10% Project: Olympus

An Elixir Umbrella project

• Zeus: Phoenix Server using Absinthe

• Hades: Ecto App (database)

• Hermes: Rabbit consumer

Olympus

Why Elixir?

• BEAM
• Immutability
• Concurrency

Why Phoenix/Absinthe?

• Open Source/Standards
• Books
• Best Practices
• Slack channels

Client Libraries

• Apollo (js/mobile)
• Neuron (elixir)
• graphql-client (ruby)

Want to learn more?

• #graphql channel

• https://github.com/teamsnap/olympus

• https://github.com/teamsnap/olympus-clients

• Friday 10% time meeting

• I am always free to talk graphql!

Thank you!