golang rest api helper

A set of small data structure that help to write rest API response.

OK response format

  {
      "status": "ok",
      "data":
      {
          "firstName": "Jon",
          "lastName": "Snow"
      }
  }

Error response format

  {
      "status": "error",
      "code": some_error_code,
      "msg": "some error message"
  }

Example

    package main

    import (
        "encoding/json"
        "github.com/hongjundu/go-rest-api-helper.v1"
        "log"
        "net/http"
    )

    func main() {
        log.Printf("server starts...")

        http.HandleFunc("/ok", wrapHandler(handlerReturnsOK))
        http.HandleFunc("/error", wrapHandler(handlerReturnsError))

        log.Fatal(http.ListenAndServe(":8080", nil))

        log.Printf("server exists")
    }

    func handlerReturnsOK(r *http.Request) (response interface{}, err error) {
        type Resp struct {
            FirstName string `json:"firstName"`
            LastName  string `json:"lastName"`
        }
        response = apihelper.NewOKResponse(Resp{FirstName: "Jon", LastName: "Snow"})
        return
    }

    func handlerReturnsError(r *http.Request) (response interface{}, err error) {
        err = apihelper.NewError(http.StatusBadRequest, "bad request")
        return
    }

    func wrapHandler(handler func(r *http.Request) (interface{}, error)) func(w http.ResponseWriter, r *http.Request) {
        return func(w http.ResponseWriter, r *http.Request) {
            var err error
            var response interface{}
            var responseBody []byte

            if response, err = handler(r); err == nil {
                responseBody, err = json.Marshal(response)
            }

            if err != nil {
                if apiErr, ok := err.(apihelper.ApiError); ok {
                    w.WriteHeader(apiErr.Code())
                }

                responseBody, _ = json.Marshal(apihelper.NewErrorResponse(err))
            }

            w.Write(responseBody)
        }
    }