如何在另一个函数中使用已连接到我的 mongodb 和集合的句柄?
How do I use the handles that I have connected to my mongodb and collections in another function?
我有一个在 mongo 上设置的数据库,其中包含一些我需要通过端点的 url 参数查询的数据。为了使用该库,我定义了一些句柄,并在单独的 setup()
函数中完成了数据库连接的整个设置,但我无法在它之外使用我需要的句柄。
package main
import (
"context"
"encoding/json"
"fmt"
"log"
"net/http"
"time"
"github.com/gorilla/mux"
"go.mongodb.org/mongo-driver/mongo"
"go.mongodb.org/mongo-driver/mongo/options"
"go.mongodb.org/mongo-driver/mongo/readpref"
)
func setup() {
clientOptions := options.Client().
ApplyURI("mongodb+srv://<username>:<password>@cluster0.um5qb.mongodb.net/<db>?retryWrites=true&w=majority")
ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
defer cancel()
client, err := mongo.Connect(ctx, clientOptions)
if err != nil {
log.Fatal(err)
}
err = client.Ping(ctx, readpref.Primary())
if err != nil {
log.Fatal(err)
}
defer client.Disconnect(ctx)
// DB := client.Database("cities-nighthack")
// Cities := DB.Collection("city")
}
// model for user endpoint
type User struct {
Email string `json:"email"`
}
// fake db to temp store users
var users []User
// checks if json is empty or not
func (u *User) IsEmpty() bool {
return u.Email == ""
}
type App struct {
Mongo *mongo.Client
}
func main() {
setup()
r := mux.NewRouter()
r.HandleFunc("/user", createUser).Methods("POST")
// r.HandleFunc("/suggest?city_name={city}", searchCity).Methods("GET")
fmt.Println("Server running at port 8080")
log.Fatal(http.ListenAndServe(":8080", r))
}
func createUser(w http.ResponseWriter, r *http.Request) {
w.Header().Set("Content-Type", "application/json")
if r.Body == nil {
json.NewEncoder(w).Encode("Must send data")
}
var user User
err := json.NewDecoder(r.Body).Decode(&user)
if err != nil {
log.Fatal(err)
}
if user.IsEmpty() {
json.NewEncoder(w).Encode("Invalid! Enter user email.")
return
}
users = append(users, user)
json.NewEncoder(w).Encode(user)
}
func (a *App) searchCity(w http.ResponseWriter, r *http.Request) {
vars := mux.Vars(r)
city := vars["city"]
}
我想我可以像这样简单地传递处理程序:
func searchCity(city *mongo.Collection) (w http.ResponseWriter, r *http.Request) {
...
}
但是,gmux 不允许您这样做,因为它隐含地传递了 http.ResponseWriter
和 *http.Request
。因此,任何输入都不能在参数中。我尝试在全球范围内声明它们,但这没有用,建议不要这样做。有人告诉我可以尝试使用闭包或结构来传递它,但我也不太明白我将如何去做。
一种方法是这样的,首先添加一个服务器类型
type server struct {
router *mux.Router
cities *mongo.Collection
}
向服务器添加路由包装器
func (s *server) routes() {
s.router.HandleFunc("/base", s.handleIndex()).Methods("GET")
}
处理函数
func (s *server) handleIndex() http.HandlerFunc {
return func(w http.ResponseWriter, r *http.Request) {
cities := s.cities.Find(...) // something like that
// write your response, etc
}
}
然后在主
func main() {
sr := &server{
router: mux.NewRouter(),
cities: getMongoDBCollection('cities') // implement this one :) should return a *mongo.Collection...
}
sr.routes()
...
}
我有一个在 mongo 上设置的数据库,其中包含一些我需要通过端点的 url 参数查询的数据。为了使用该库,我定义了一些句柄,并在单独的 setup()
函数中完成了数据库连接的整个设置,但我无法在它之外使用我需要的句柄。
package main
import (
"context"
"encoding/json"
"fmt"
"log"
"net/http"
"time"
"github.com/gorilla/mux"
"go.mongodb.org/mongo-driver/mongo"
"go.mongodb.org/mongo-driver/mongo/options"
"go.mongodb.org/mongo-driver/mongo/readpref"
)
func setup() {
clientOptions := options.Client().
ApplyURI("mongodb+srv://<username>:<password>@cluster0.um5qb.mongodb.net/<db>?retryWrites=true&w=majority")
ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
defer cancel()
client, err := mongo.Connect(ctx, clientOptions)
if err != nil {
log.Fatal(err)
}
err = client.Ping(ctx, readpref.Primary())
if err != nil {
log.Fatal(err)
}
defer client.Disconnect(ctx)
// DB := client.Database("cities-nighthack")
// Cities := DB.Collection("city")
}
// model for user endpoint
type User struct {
Email string `json:"email"`
}
// fake db to temp store users
var users []User
// checks if json is empty or not
func (u *User) IsEmpty() bool {
return u.Email == ""
}
type App struct {
Mongo *mongo.Client
}
func main() {
setup()
r := mux.NewRouter()
r.HandleFunc("/user", createUser).Methods("POST")
// r.HandleFunc("/suggest?city_name={city}", searchCity).Methods("GET")
fmt.Println("Server running at port 8080")
log.Fatal(http.ListenAndServe(":8080", r))
}
func createUser(w http.ResponseWriter, r *http.Request) {
w.Header().Set("Content-Type", "application/json")
if r.Body == nil {
json.NewEncoder(w).Encode("Must send data")
}
var user User
err := json.NewDecoder(r.Body).Decode(&user)
if err != nil {
log.Fatal(err)
}
if user.IsEmpty() {
json.NewEncoder(w).Encode("Invalid! Enter user email.")
return
}
users = append(users, user)
json.NewEncoder(w).Encode(user)
}
func (a *App) searchCity(w http.ResponseWriter, r *http.Request) {
vars := mux.Vars(r)
city := vars["city"]
}
我想我可以像这样简单地传递处理程序:
func searchCity(city *mongo.Collection) (w http.ResponseWriter, r *http.Request) {
...
}
但是,gmux 不允许您这样做,因为它隐含地传递了 http.ResponseWriter
和 *http.Request
。因此,任何输入都不能在参数中。我尝试在全球范围内声明它们,但这没有用,建议不要这样做。有人告诉我可以尝试使用闭包或结构来传递它,但我也不太明白我将如何去做。
一种方法是这样的,首先添加一个服务器类型
type server struct {
router *mux.Router
cities *mongo.Collection
}
向服务器添加路由包装器
func (s *server) routes() {
s.router.HandleFunc("/base", s.handleIndex()).Methods("GET")
}
处理函数
func (s *server) handleIndex() http.HandlerFunc {
return func(w http.ResponseWriter, r *http.Request) {
cities := s.cities.Find(...) // something like that
// write your response, etc
}
}
然后在主
func main() {
sr := &server{
router: mux.NewRouter(),
cities: getMongoDBCollection('cities') // implement this one :) should return a *mongo.Collection...
}
sr.routes()
...
}