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https://github.com/pgutkowski/KGraphQL
Pure Kotlin GraphQL implementation
https://github.com/pgutkowski/KGraphQL
graphql kotlin
Last synced: 2 months ago
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Pure Kotlin GraphQL implementation
- Host: GitHub
- URL: https://github.com/pgutkowski/KGraphQL
- Owner: pgutkowski
- License: mit
- Archived: true
- Created: 2017-05-29T21:34:47.000Z (over 7 years ago)
- Default Branch: master
- Last Pushed: 2019-05-17T06:42:09.000Z (over 5 years ago)
- Last Synced: 2024-08-01T13:34:53.948Z (5 months ago)
- Topics: graphql, kotlin
- Language: Kotlin
- Homepage:
- Size: 590 KB
- Stars: 285
- Watchers: 12
- Forks: 81
- Open Issues: 26
-
Metadata Files:
- Readme: README.MD
- License: LICENSE.md
Awesome Lists containing this project
- awesome-ccamel - pgutkowski/KGraphQL - Pure Kotlin GraphQL implementation (Kotlin)
README
# KGraphQL
[](https://travis-ci.org/pgutkowski/KGraphQL)
[](https://codebeat.co/projects/github-com-pgutkowski-kgraphql-master)
[](https://coveralls.io/github/pgutkowski/KGraphQL?branch=master)
[ ](https://bintray.com/pgutkowski/Maven/KGraphQL/_latestVersion)
[](https://github.com/KotlinBy/awesome-kotlin)
# Disclaimer
I am no longer able to maintain this project. Please go to https://github.com/aPureBase/KGraphQL, where KGraphQL is still developed.
KGraphQL is [Kotlin](https://kotlinlang.org/) implementation of [GraphQL](http://graphql.org/). It provides rich DSL to setup GraphQL schema.
## Introduction
As example, let's partially reproduce part of Star Wars schema from [official GraphQL tutorial](http://graphql.org/learn/queries/). First, we need to define our domain model, by plain kotlin classes:
```kotlin
enum class Episode {
NEWHOPE, EMPIRE, JEDI
}
interface Character {
val id : String
val name : String?
val friends: List
val appearsIn: Set
}
data class Human (
override val id: String,
override val name: String?,
override val friends: List,
override val appearsIn: Set,
val homePlanet: String,
val height: Double
) : Character
data class Droid (
override val id: String,
override val name: String?,
override val friends: List,
override val appearsIn: Set,
val primaryFunction : String
) : Character
```
Next, we define our data
``` kotlin
val luke = Human("2000", "Luke Skywalker", emptyList(), Episode.values().toSet(), "Tatooine", 1.72)
val r2d2 = Droid("2001", "R2-D2", emptyList(), Episode.values().toSet(), "Astromech")
```
Then, we can create schema:
``` kotlin
//KGraphQL#schema { } is entry point to create KGraphQL schema
val schema = KGraphQL.schema {
//configure method allows you customize schema behaviour
configure {
useDefaultPrettyPrinter = true
}
//create query "hero" which returns instance of Character
query("hero") {
resolver {episode: Episode -> when(episode){
Episode.NEWHOPE, Episode.JEDI -> r2d2
Episode.EMPIRE -> luke
}}
}
//create query "heroes" which returns list of luke and r2d2
query("heroes") {
resolver{ -> listOf(luke, r2d2)}
}
//kotlin classes need to be registered with "type" method
//to be included in created schema type system
//class Character is automatically included,
//as it is return type of both created queries
type()
type()
enum()
}
```
Now, we can query our schema:
```kotlin
//query for hero from episode JEDI and take id, name for any Character, and primaryFunction for Droid or height for Human
schema.execute("{hero(episode: JEDI){
id
name
... on Droid{primaryFunction}
... on Human{height}
}
}")
```
Returns:
```json
{
"data" : {
"hero" : {
"id" : "2001",
"name" : "R2-D2",
"primaryFunction" : "Astromech"
}
}
}
```
Query for all heroes:
```kotlin
//query for all heroes and take id, name for any Character, and primaryFunction for Droid or height for Human
schema.execute("{heroes {
id
name
... on Droid{primaryFunction}
... on Human{height}
}
}")
```
Returns:
```json
{
"data" : {
"heroes" : [ {
"id" : "2000",
"name" : "Luke Skywalker",
"height" : 1.72
}, {
"id" : "2001",
"name" : "R2-D2",
"primaryFunction" : "Astromech"
} ]
}
}
```
As stated by GraphQL specification, client receives only what is requested. No more, no less.
Detailed documentation can be found in [wiki](https://github.com/pgutkowski/KGraphQL/wiki). For more examples, see KGraphQL demo application: [KGraphQL-NBA2012](https://github.com/pgutkowski/KGraphQL-NBA2012)
## Building
To build KGraphQL you only need to have JDK8 installed. invoke
``` bash
./gradlew build
```
To perform local build.
## Versioning
The versioning is following [Semantic Versioning](http://semver.org/)
## Links
Specification : http://facebook.github.io/graphql/
## License
KGraphQL is Open Source software released under the [MIT license](https://opensource.org/licenses/MIT)