Go chi 渲染器具有难以处理绑定列表的困难

Question

转到此处。试图让 chi 渲染器返回Order结构实例的列表，并得到我不明白的编译器错误：

package myapp
import (
"net/http"
"github.com/go-chi/render"
)
type Order struct {
OrderId    string
Status     string
}
func (*Order) Bind(r *http.Request) error {
return nil
}
func GetAllOrderByCustomerId(dbClient DbClient, customerId string) http.HandlerFunc {
return func(w http.ResponseWriter, r *http.Request) {
// fetch all customer orders from the DB
orders,err := dbClient.FetchAllOrdersByCustomerId(customerId)
if err != nil {
log.Error("unable to fetch orders for customer", err)
render.Render(w, r, NewInternalServerError(err))
return
}
render.Bind(r, &orders)
return
}
}

当我去编译这段代码时，我得到：

fizz/buzz/myapp/order_fetcher.go:136:20: cannot use &orders (type *[]Order) as type render.Binder in argument to render.Bind:
*[]Order does not implement render.Binder (missing Bind method)

因此，即使我已经为Order定义了Bind，它似乎也不会自动将该Bind应用于Orders的集合/列表。

谁能看到我错过了什么？一些端点将只返回一个Order，而其他端点(如这个端点(需要能够返回Orders的集合/列表。

Answer 1

与存储库中的示例chi一样，您必须创建一个帮助程序方法来呈现某些内容的列表，在您的例子中是订单列表。

首先，您必须实现render.Renderer方法，然后创建一个帮助程序方法来构建render.Renderer列表。

我从这里的例子中改编了你的代码：

type Order struct {
OrderId string
Status  string
}
// Render implement render.Renderer
func (*Order) Render(w http.ResponseWriter, r *http.Request) error {
// do something
return nil
}
// newOrderList is a helper method to make list of render.Renderer
func newOrderList(orders []*Order) []render.Renderer {
list := []render.Renderer{}
for _, order := range orders {
list = append(list, order)
}
return list
}
func GetAllOrderByCustomerId(dbClient DbClient, customerId string) http.HandlerFunc {
return func(w http.ResponseWriter, r *http.Request) {
// fetch all customer orders from the DB
orders, err := dbClient.FetchAllOrdersByCustomerId(customerId)
if err != nil {
log.Error("unable to fetch orders for customer", err)
render.Render(w, r, NewInternalServerError(err))
return
}
// render list of orders
render.RenderList(w, r, newOrderList(orders))
return
}
}