jsonenums/server/server.go
Daved c55a706513 Added prefix flag, and updated file name output. Changed parser
package's ParsePackage to take prefix and updated related skip
conditional.  Also updated args in call to ParsePackage within
server. Last paragraph of main package comment was updated, along
with the second to last paragraph of readme.
2015-04-23 09:50:48 -07:00

116 lines
2.7 KiB
Go

// Copyright 2014 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// Server is an http server that provides an alternative way of generating code
// based on int types and the constants defined with it.
//
// Use the http flag to change the address on which the server will listen for
// requests. The default is 127.0.0.1:8080.
package main
import (
"bytes"
"fmt"
"io/ioutil"
"log"
"net/http"
"os"
"path/filepath"
"text/template"
"go/format"
"github.com/campoy/jsonenums/parser"
)
func init() {
http.Handle("/generate", handler(generateHandler))
}
func generateHandler(w http.ResponseWriter, r *http.Request) error {
if r.Method != "GET" {
return codeError{fmt.Errorf("only GET accepted"), http.StatusMethodNotAllowed}
}
code := r.FormValue("code")
if code == "" {
return codeError{fmt.Errorf("no code to be parsed"), http.StatusBadRequest}
}
typ := r.FormValue("type")
if typ == "" {
return codeError{fmt.Errorf("no type to be analyzed"), http.StatusBadRequest}
}
dir, err := createDir(code)
if err != nil {
return err
}
defer os.RemoveAll(dir)
pkg, err := parser.ParsePackage(dir, "", "")
if err != nil {
return fmt.Errorf("parse package: %v", err)
}
values, err := pkg.ValuesOfType(typ)
if err != nil {
return fmt.Errorf("find values: %v", err)
}
t, err := template.New("code").Parse(r.FormValue("template"))
if err != nil {
return codeError{fmt.Errorf("parse template: %v", err), http.StatusBadRequest}
}
var data = struct {
PackageName string
TypeName string
Values []string
}{pkg.Name, typ, values}
var buf bytes.Buffer
if err := t.Execute(&buf, data); err != nil {
return codeError{fmt.Errorf("execute template: %v", err), http.StatusBadRequest}
}
src, err := format.Source(buf.Bytes())
if err != nil {
return codeError{fmt.Errorf("code generated is not valid: %v\n%v", err, buf.String()), http.StatusBadRequest}
}
w.Write(src)
return nil
}
func createDir(content string) (string, error) {
dir, err := ioutil.TempDir("", "jsonenums")
if err != nil {
return "", fmt.Errorf("create tmp dir: %v", err)
}
f, err := os.Create(filepath.Join(dir, "main.go"))
if err != nil {
os.RemoveAll(dir)
return "", fmt.Errorf("create tmp file: %v", err)
}
f.WriteString(content)
f.Close()
return dir, err
}
type handler func(http.ResponseWriter, *http.Request) error
func (h handler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
err := h(w, r)
if err != nil {
code := http.StatusInternalServerError
if cErr, ok := err.(codeError); ok {
code = cErr.code
} else {
log.Printf("%v: %v", r.URL, code)
}
http.Error(w, err.Error(), code)
}
}
type codeError struct {
error
code int
}