handler

handler

-- Handler builds typed golang http handlers.

Given a func F :

func F(x X) (status int, resp interface{}) )

and a format pkg like encoding/json.

handler will create an http handler :

func FHandlerFORMAT(w http.ResponseWriter, r *http.Request)
// decode
// call F()

The file is created in the same package and directory as the package that defines F.

ex:

//go:generate handler -func=PutJob -format=json
package jober

type job struct { A string }

func PutJob(j job) (int, interface{}) {
  return nil, 200
}

running

go generate pkg.go/foo/jober

will create generated_handlers.go:

import "encoding/json"

func PutJobHandlerJSON(w http.ResponseWriter, r *http.Request) {
    x := job{}
    err := json.NewDecoder(r.Body).Decode(&x)
    if err != nil {
        w.WriteHeader(http.StatusBadRequest)
        return
    }
    s, resp := PutJob(x)
    w.WriteHeader(s)
    json.NewEncoder(w).Encode(resp)
}

so now you can just worry about what PutJob does.

pkg existence will be checked. The pkg needs to have funcs :

func NewDecoder(r io.Reader) *Decoder
func NewEncoder(w io.Writer) *Encoder

and types

type Encoder interface {
    Encode(v interface{}) error
}
type Decoder interface {
    Decode(v interface{}) error
}

Typically this process would be run using go generate, by writing:

//go:generate handler -encoding encoding/json -func PutJob

at the beginning of your .go file

The -encoding and the -func flags accepts a comma-separated list of strings. So you can have n handler working in m encoding

Name of the created file can be overridden with the -output flag.

Support of contexts is comming soon.