GraphQl - One endpoint to rule your application - Open-Source Kerala 2017

Transcript

1. GRAPHQL - ONE ENDPOINT TO RULE YOUR APPLICATION Shaiju E
2. { name: 'Shaiju E', email: 'eshaiju@gmail.com', tech_blog: 'tech.eshaiju.in', github: 'eshaiju', twitter: 'eshaiju', facebook: 'eshaiju', linkedin: 'eshaiju' }
4. Agenda Modern API technologies & challenges What it is, what it’s not and what GraphQL aims to solves? Supported languages Who’s using GraphQL?
5. API Technologies REST SOAP gRPC OData And many more ...
6. REST Architectural style of the web Resources a single resource e.g. /api/posts Verbs GET, PUT, DELETE & POST
7. So why are we looking at GraphQL?
8. Modern API considerations Efficiency Predictability Versioning Caching Tooling Documentation
9. Lets look at an example...
10. Comment Post User What kind of data is needed? ​
11. GET /comments/post_id=1 GET /comments/post_id=2 GET /comments/post_id=5 GET /posts GET /users/1 GET /users/2 GET /users/5 Multiple round trips! (Under-fetching) Client Server
12. GET /comments/post_id=1 GET /comments/post_id=2 GET /comments/post_id=5 GET /posts GET /users/1 GET /users/2 GET /users/5 Client Server Includes /api/posts?include=users,comments
13. "post": { "id": 1, "title": "A GraphQL Server Implementation", "url": "http://tech.eshaiju.in/blog/2017/05/ "body": null, "votes": 100, "published_at": "11 Jul 2017 00 00 AM", "auther_name": "Shaiju E", "created_at": "2017-07-11 12:57:20 UTC", "updated_at": "2017-07-11 13:15:50 UTC" } "post": { "id": 1, "title": "A GraphQL Server Implementation", "url": "http://tech.eshaiju.in/blog/2017/05/06/a-graphql-server-implementation-ruby-on-rails/" } What I get What I care about Over-fetching of data
14. Custom Endpoints ​ /posts_with_everything_i_need /posts_with_everything_i_need_with_author_v2 /posts_with_everything_i_need_with_author_and_images /posts_with_everything_i_need_with_author_and_images_for_mobile /posts_with_everything_i_need_with_author_and_images_for_tab_v2
15. GraphQL
16. What GraphQL is NOT It's not about graph databases and graph search It's not about data storage it's not language specific it's not a library
17. What GraphQL IS GraphQL is a query language for APIs is a new API standard that provides an alternative to REST Declarative data fetching - The client specifies what data shapes, and the server returns that data in exact same shape. GraphQL server only exposes a single endpoint and responds with precisely the data a client asked for GraphQL
18. query { post(id: 1){ title url published_at } } Query
19. query { post(id: 1){ title url published_at } } { "data": { "post": { "title": "A GraphQL Server Implementa "url": "http://tech.eshaiju.in/blog/2 "published_at": "2017-07-11 00:00:00 } } }
20. query { users{ id name } post(id: 1){ title url published_at author{ name } comments{ body author{ name } } } } { "data": { "users": [ { "id": 1, "name": "Shaiju E" }, { "id": 2, "name": "Awin" } ], "post": { "title": "A GraphQL Server Implementation", "url": "http://tech.eshaiju.in/blog/2017/05/06/a-graphql-se "published_at": "11 Jul 2017 00 00 AM", "author": { "name": "Shaiju E" }, "comments": [ { "body": "Good post", "author": { "name": "Awin" } } ] } } }
21. POST /api curl -XPOST -d 'query { post(id: 1) { title url } }' http://localhost:3000/api
22. mutation addComment{ addComment(input: { comment: "New comment", post_id: 1, author_id: 1}) { post{ id title comments{ body user{ name } } } } } Mutations are used to change your data Mutations are the equivalent to the POST, PUT, PATCH and DELETE in HTTP/REST. Mutation
23. PostType = GraphQL::ObjectType.define do name "Post" description "Post and details" field :id, types.Int field :title, types.String do resolve -> (post, args, ctx) { post.title } end field :body, types.String field :url, types.String field :votes, types.Int field :published_at, types.String do resolve -> (post, args, ctx) { post.published_at.strftime('%d %b %Y %H %M %p') } deprecation_reason 'This field is deprecated' end field :comments, types[CommentType] field :author, UserType end Implementation - Type System
24. What problems does it help us solve?
25. query { post(id: 1){ title url published_at } } Efficiency { "data": { "post": { "title": "A GraphQL Server Implementa "url": "http://tech.eshaiju.in/blog/2 "published_at": "2017-07-11 00:00:00 } } }
26. Efficiency query { users{ id name } post(id: 1){ title url published_at author{ name } comments{ body author{ name } } } } { "data": { "users": [ { "id": 1, "name": "Shaiju E" }, { "id": 2, "name": "Awin" } ], "post": { "title": "A GraphQL Server Implementation", "url": "http://tech.eshaiju.in/blog/2017/05/06/a-graphql-server-impl "published_at": "11 Jul 2017 00 00 AM", "author": { "name": "Shaiju E" }, "comments": [ { "body": "Good post", "author": { "name": "Awin" } } ] } } }
27. Tooling & Documentation
28. Tooling & Documentation
29. Versioning Evolve your API without versions GraphQL only returns the data that's explicitly requested New capabilities can be added via new types and new fields on those types without creating a breaking change. Deprecate older fields
30. Server Libraries Ruby C# / .NET Elixir Erlang Go Groovy Java JavaScript PHP Python Scala Clojure
31. Who’s using GraphQL?
32. Advantages Efficient ​ Predictable Flexible Auto Documentation
33. References http://graphql-ruby.org/ http://tech.eshaiju.in/blog/categories/graphql/ https://www.howtographql.com/​ https://www.youtube.com/watch?v=eD7kLFGOgVw
34. Thank you!