GraphQL is a query language for APIs and a runtime for fulfilling those queries with your existing data. GraphQL provides a complete and understandable description of the data in your API, gives clients the power to ask for exactly what they need and nothing more, makes it easier to evolve APIs over time, and enables powerful developer tools.

1. GraphQL
PRAVEEN SINGH BORA

2. What GraphQL is not?
What is GraphQL?
2

3. Traditional Client - Server relationship
3
App
Server
iOS
View1
Droid
View1
Web
View2
Data(id: 10)
Data(id: 10)
Data(id: 10)
Model
Model
Model

4. Traditional Client - Server relationship
4
App
Server
iOS
Complex View
Data1(id: 10)
Data 2(id: 10)
Data 3(id: 10)
Model 1
Model 2
Model 3
Sad Server Slow App
N + 1 Query Problem

5. GraphQL Client - Server relationship
5
App
Server
iOS
Complex View
Capabilities (Type System)
Requirements (data queries)
Type System

6. GraphQL Client - Server relationship
6
App
Server
iOS
Complex View
Data Shape
Client Specific Data
Type System
Slow App

7. GRAPH QL
Graph QL Query
query GetNames {
users {
firstName
lastName
}
}
type Character {
name: String!
appearsIn: [Episode]!
}
7
GraphQL Response
{
‘users’ :
[
{
firstName: ‘John’,
lastName: ‘Smith’
}
]
}

8. TYPE SYSTEM
Type System
Object Types and Fields
Arguments
The Query and Mutation Types
Scalar Types
Enumeration Types
Lists and Non-Null
Interfaces 8

9. APPLICATION DATA GRAPH - MENTAL MODEL
9

10. GRAPH QL
10

11. GRAPH QL
11

12. GRAPHQL QUERY
12
Parse Validate Execute

13. GRAPHQL SUBSCRIPTION
EVENT STREAM, RESPONSE STREAM, SOURCE STREAM, EVENT COMPLETION, SUBSCRIPTION CANCELLATION, ERROR N COMPLETION, MAPPER,
13
Parse Validate Subscribe

14. GRAPHQL SUBSCRIPTION
14
Parse
(AST)
Validate
Create
Source
Mapper
Execute

15. GRAPHQL SUBSCRIPTION
15
Create
Source
Subscribe to the pub sub service
Watch for database writes / listen for triggers
Process the Kafka Stream
Listen to incoming http calls
Incoming stock prices per tick
or anything which could create an event stream

16. GRAPHQL SUBSCRIPTION
16
P
a
r
s
e
V
a
li
d
a
t
e
Create
Source
Mapper
Execute
Client
Internet

17. 17
TransportGraphQL Client
Http
Graph QL Query

18. GRAPHQL SUBSCRIPTION
18
I/OGraphQL
Client
I/O

19. GRAPHQL SUBSCRIPTION
19
I/O I/O
Web Sockets
MQTT or RabbitMQ
Post to Web hooks
Send an email etc

20. MULTIPLE SUBSCRIPTION ?
20
I/OGraphQL
Client
I/O

21. MULTIPLEXING
SCALING?
21
I/OGraphQL
Client
I/O

22. 22
P
a
r
s
e
V
a
li
d
a
t
e
Create
Source
Mapper
Execute
Client
ExecuteExecuteExecute

23. 23
P
a
r
s
e
V
a
li
d
a
t
e
Create
Source
Mapper
Execute
Client
ExecuteExecuteExecuteThrottling ???

24. THANKS
Constructive feedbacks