README
¶
autohandler
This is a go:generate program that wraps your functions so you can use them in callers expecting a net/http HandlerFunc.
I don't expect this to be useful to anyone out of the box but as a go:generate example or a skeleton on which to build other wrapper generation, it may be helpful.
It expects something like this:
//go:generate autohandler -pkg myserver -out wrappers.go
package myserver
import "net/http"
type Json string //mimetype application/json
type Html string //mimetype text/html
type Server struct {}
func (self *Server) ApiMethod(name string, flag bool) (Json, int) {
// ...
return `{"success":"maybe"}`, http.StatusOK
}
// note: *http.Request gets passed through from wrapper
func (self *server) OtherApiMethod(req *http.Request) (Html, int) {
return "<html><body>hello</body></html>", http.StatusOK
}
and produces something like this:
package myserver
import (
"io"
"net/http"
"encoding/json"
)
func (self *Server) HandleApiMethod(w http.ResponseWriter, req *http.Request){
w.Header().Set("Content-Type", "application/json")
raw := make([]byte, 0, 0)
if _, err := req.Body.Read(raw); err != nil {panic(err)}
var parsed map[string]interface{}
if err := json.Unmarshal(raw, &parsed); err != nil {panic(err)}
body, retcode := self.ApiMethod(parsed["name"].(string), parsed["flag"].(bool))
w.WriteHeader(retcode)
io.WriteString(w, string(body))
}
// todo: show wrapper for OtherApiMethod too
translation rules
- the parser will try to translate any function that returns (MimeString, int). MimeString is any string override marked with a comment like
type T string //mimetype a/b - if any argument has type
*http.Request, it gets passed through to the wrapped function - if any argument has type
http.ResponseWriter, it gets passed through and the response of the wrapped function is ignored (i.e. it's assumed the function writes its own output). Warning: both the response and status code are returned. This is pretty confusing because the function looks like it's returning that stuff. (todo: ResponseWriter functions shouldn't have a return) - for other arguments, the wrapper will try to cast them out of a json request body and crash if it can't. (This is subideal. We should fail more gently and interpolate zero values for missing keys)
- interface args aren't cast
- json parsing of the body only happens if necessary -- if your function has 0 args or just an *http.Request arg, the json code isn't emitted in the wrapper
getting started
go get github.com/abe-winter/autohandlerto install the command- use a //go:generate comment in your source code (see example above)
- run
go generate && go buildin your package dir
Documentation
¶
There is no documentation for this package.
Source Files
Click to show internal directories.
Click to hide internal directories.