gqlgen golang graphql server 基本試用

gqlgen golang 的graphql server

具體代碼參考https://github.com/rongfengliang/gqlgen-demo

特點

• 模型優先
• 型別安全
• 代碼產生

安裝

go get -u github.com/vektah/gqlgen

建立schema

schema.graphql

type Todo {id: ID!text: String!done: Boolean!user: User!}type User {id: ID!name: String!}type Query {todos: [Todo!]!}input NewTodo {text: String!userId: String!}type Mutation {createTodo(input: NewTodo!): Todo!}

建立model

• User (model/user.go)

package model// User user infotype User struct {    ID string    Name string}

• Todo (model/todo.go)

package model// Todo todo inotype Todo struct {    ID string    Text string    Done bool    UserID string}

產生graphql 運行時代碼

• 配置模型關聯

  gqlgen.yml

schema: schema.graphqlexec:  filename: graph/generated.gomodel:  filename: model/generated.gomodels:  Todo:    model: github.com/rongfengliang/gqlgen-app/model.Todo  User:    model: github.com/rongfengliang/gqlgen-app/model.User

• 產生bingings

gqlgen

• 編寫 resolver

  graph/graph.go

package graphimport (    "context"    "fmt"    "math/rand"    model "github.com/rongfengliang/gqlgen-app/model")type App struct {    todos []model.Todo}func (a *App) Mutation() MutationResolver {    return &mutationResolver{a}}func (a *App) Query() QueryResolver {    return &queryResolver{a}}func (a *App) Todo() TodoResolver {    return &todoResolver{a}}type queryResolver struct{ *App }func (a *queryResolver) Todos(ctx context.Context) ([]model.Todo, error) {    return a.todos, nil}type mutationResolver struct{ *App }func (a *mutationResolver) CreateTodo(ctx context.Context, input model.NewTodo) (model.Todo, error) {    todo := model.Todo{        Text: input.Text,        ID: fmt.Sprintf("T%d", rand.Int()),        UserID: input.UserId,    }    a.todos = append(a.todos, todo)    return todo, nil}type todoResolver struct{ *App }func (a *todoResolver) User(ctx context.Context, it *model.Todo) (model.User, error) {    return model.User{ID: it.UserID, Name: "user " + it.UserID}, nil}

入口代碼編寫

• main.go

package mainimport (    "fmt"    "log"    "net/http"    "github.com/rongfengliang/gqlgen-app/graph"    "github.com/vektah/gqlgen/handler")func main() {    http.Handle("/", handler.Playground("Todo", "/query"))    http.Handle("/query", handler.GraphQL(graph.NewExecutableSchema(&graph.App{})))    fmt.Println("Listening on :8080")    log.Fatal(http.ListenAndServe(":8080", nil))}

運行

go run main.go

效果

整合dep

dep init 

參考資料

https://gqlgen.com/getting-started/
https://github.com/vektah/gqlgen
https://github.com/rongfengliang/gqlgen-demo