In short, this is a GraphQL request JSON body builder for Kotlin. It will generate the JSON string for request body that work with GraphQL Server. For example, we have the GraphQL query for list all the notes.

    query {
        notes {
            id
            createdDate
            content
            author {
                name
                avatarUrl(size: 100)
            }
        }
    }

And here is how we write it in Kotlin using Kraph.

    Kraph {
        query {
            fieldObject("notes") {
                field("id")
                field("createdDate")
                field("content")
                fieldObject("author") {
                    field("name")
                    field("avatarUrl", mapOf("size" to 100))
                }
            }
        }
    }

As you can see, we can achieve our goal with just a few tweaks from the original query.

NOTE: Kraph is still in an early stage. The usage may change in further development.

• DSL builder style. Make it easier to read and use.
• Support CursorConnection field and Input object for mutation in Relay.

Adding Kraph to build.gradle

    repositories {
        jcenter()
    }
    
    dependencies {
        compile "com.taskworld.kraph:kraph:x.y.z"
    }

If you are not familiar with GraphQL syntax, We recommended to read on this specification to have an overview of how to write Graphql. Usually, you should be able to use the query from other tools(e.g. GraphiQL) with a few tweaks. First, let's see what Kraph provided for you.

• query represents QUERY operation in GraphQL. It can be named by passing String as a parameter. The query block can only contains field or fieldObject.

    /*
    * query GetUsers {
    *   ...
    * }
    */
    Kraph {
        query("GetUsers") {
            ...
        }
    }

• field and fieldObject represents FIELD in SELECTION SET. The different is that fieldObject allow you to have it owns SELECTION SET, which represent data object in GraphQL. Both of them have a parameter named args for arguments in paritcular field.

    /*
    * query {
    *   users {
    *       name
    *       email
    *       avatarUrl(size: 100)
    *   }
    * }
    */
    Kraph {
        query {
            fieldObject("users") {
                field("name")
                field("email")
                field("avatarUrl", args = mapOf("size" to 100))
            }
        }
    }

• mutation represents MUTATION operation in GraphQL. The mutation block can have only contains func.

    /*
    * mutation updateUserProfile {
    *   ...
    * }
    */
    Kraph {
        mutation("UpdateUserProfile") {
            ... 
        }
    }

• func represents as FIELD inside MUTATION block. The reason we did not used fieldObject

We use Github issues for tracking bugs and requests. Any feedback and/or PRs is welcome.