graphql-go define field type as object

Question

Using graphql-go how do we handle nested objects as in given api returns the following in resolver

{ id:"34", name:"something", region:{ id:34, name: "San jose" } }

how do we implement for region: "region": &graphql.Field{ Type: graphql.??, },

Answer 1

Here is an example using github.com/graphql-go/graphql v0.7.9 :

package main

import (
    "encoding/json"
    "fmt"
    "net/http"

    "github.com/graphql-go/graphql"
)

type region struct {
    ID   int    `json:"id"`
    Name string `json:"name"`
}

type user struct {
    ID     string `json:"id"`
    Name   string `json:"name"`
    Region region `json:"region"`
}

var aRegion = region{ID: 34, Name: "San jose"}
var aUser = user{ID: "34", Name: "something", Region: aRegion}

var regionType = graphql.NewObject(graphql.ObjectConfig{
    Name: "Region",
    Fields: graphql.Fields{
        "id":   &graphql.Field{Type: graphql.Int},
        "name": &graphql.Field{Type: graphql.String},
    },
})

var userType = graphql.NewObject(graphql.ObjectConfig{
    Name: "User",
    Fields: graphql.Fields{
        "id":   &graphql.Field{Type: graphql.String},
        "name": &graphql.Field{Type: graphql.String},
        "region": &graphql.Field{
            Type: regionType,
            Resolve: func(p graphql.ResolveParams) (interface{}, error) {
                source, ok := p.Source.(user)
                fmt.Printf("%#v\n", source)
                fmt.Println("ok:", ok)
                return source.Region, nil
            },
        },
    },
})

var queryType = graphql.NewObject(graphql.ObjectConfig{
    Name: "Query",
    Fields: graphql.Fields{
        "user": &graphql.Field{
            Type: userType,
            Resolve: func(p graphql.ResolveParams) (interface{}, error) {
                return aUser, nil
            },
        },
    },
})

func executeQuery(query string, schema graphql.Schema) *graphql.Result {
    result := graphql.Do(graphql.Params{
        Schema:        schema,
        RequestString: query,
    })
    if len(result.Errors) > 0 {
        fmt.Printf("wrong result, unexpected errors: %v", result.Errors)
    }
    return result
}

func main() {
    var schema, _ = graphql.NewSchema(graphql.SchemaConfig{
        Query: queryType,
    })
    http.HandleFunc("/graphql", func(w http.ResponseWriter, r *http.Request) {
        result := executeQuery(r.URL.Query().Get("query"), schema)
        json.NewEncoder(w).Encode(result)
    })
    fmt.Println("Now server is running on port 8080")
    fmt.Println("Access the web app via browser at 'http://localhost:8080'")
    http.ListenAndServe(":8080", nil)
}

Send GraphQL request using curl :

~ curl -g 'http://localhost:8080/graphql?query={user{id,name,region{id,name}}}'
{"data":{"user":{"id":"34","name":"something","region":{"id":34,"name":"San jose"}}}}

Logs of server:

~ go run main.go
Now server is running on port 8080
Access the web app via browser at 'http://localhost:8080'
main.user{ID:"34", Name:"something", Region:main.region{ID:34, Name:"San jose"}}
ok: true
main.user{ID:"34", Name:"something", Region:main.region{ID:34, Name:"San jose"}}
ok: true