Up And Running With GraphQL

A hands-on introduction to GraphQL.

By Phillip Kigenyi - Software Engineer (Sellio) at Developer Circle Kampala

Transcript

1. Graphql Kigenyi Phillip | codephillip@gmail.com
2. Flow What is Graphql Why Graphql Graphql vs REST Graphql concepts Demo Useful Links Q & A http://bit.ly/gqslides http://bit.ly/gqproject
3. What is Graphql • GraphQL is a query language for your API, and a server-side runtime for executing queries by using a type system you define for your data • Declarative data fetching. The query is shaped just like the data it returns • Single endpoint. Multiple queries • GraphQL APIs are organized in terms of types and fields, not endpoints
4. Why Graphql • Get all app data in single request • Reduce over fetching and under fetching • Send a GraphQL query to your API and get exactly what you need • Evolve your API without versions • Self documenting. Introspection tool • Efficient data loading and usage
5. Graphql vs REST
6. REST
7. GRAPHQL
8. • GraphQL Schema Definition Language. Define the schema of an API. Contract between the client and server Graphql concepts
9. Graphql concepts • Relation in GraphQL Schema Definition Language
10. Graphql concepts • Fields. Specify the fields you need
11. Graphql concepts • Aliases. Query for the same field with different arguments
12. Graphql concepts • Arguments. Pass arguments to fields
13. Graphql concepts • Fragments. Get different results without repeating yourself
14. Graphql concepts • Introspection. Clients and tools query the type system. Self documenting • __Schema, __Type, __TypeKind, __Field, __InputValue, __EnumValue, __Directive - These all are preceded with a double underscore,
15. Graphql concepts • Hierarchical. The query is shaped just like the data it returns • Strong-typing. Syntactically correct and valid within the GraphQL type system before execution • Types. ◦ Default scalar types. Float, Boolean, Float, Int ◦ User defined types. Enums, Interfaces, Union types ◦ Root types. Query, Mutation and subscription. By default exists on the root • Query. Client‐specified queries, client defines how result should appear • Mutations. Creating, Updating and deleting • Subscriptions. Connect to the server and wait for response. Similar to webhooks
16. Demo
17. Useful Links • https://graphql.org • https://www.howtographql.com • https://www.howtographql.com/graphql-python/0-introduction/ • https://dev-blog.apollodata.com/the-basics-of-graphql-in-5-links-9e1dc4cac055 • https://reactjs.org/blog/2015/05/01/graphql-introduction.html • https://github.com/howtographql/graphql-python • https://www.youtube.com/watch?v=BG1H6IrNbAk • https://www.youtube.com/watch?v=HebnYlIaK_0
18. Thank You Q & A