mirror of
https://github.com/golang/go
synced 2024-11-23 23:20:08 -07:00
77 lines
1.6 KiB
Go
77 lines
1.6 KiB
Go
// compile
|
|
|
|
// Copyright 2011 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.
|
|
|
|
// This file contains the code snippets included in "Error Handling and Go."
|
|
|
|
package main
|
|
|
|
import (
|
|
"net/http"
|
|
"text/template"
|
|
)
|
|
|
|
type appError struct {
|
|
Error error
|
|
Message string
|
|
Code int
|
|
}
|
|
|
|
// STOP OMIT
|
|
|
|
type appHandler func(http.ResponseWriter, *http.Request) *appError
|
|
|
|
func (fn appHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
|
|
if e := fn(w, r); e != nil { // e is *appError, not error.
|
|
c := appengine.NewContext(r)
|
|
c.Errorf("%v", e.Error)
|
|
http.Error(w, e.Message, e.Code)
|
|
}
|
|
}
|
|
|
|
// STOP OMIT
|
|
|
|
func viewRecord(w http.ResponseWriter, r *http.Request) *appError {
|
|
c := appengine.NewContext(r)
|
|
key := datastore.NewKey(c, "Record", r.FormValue("id"), 0, nil)
|
|
record := new(Record)
|
|
if err := datastore.Get(c, key, record); err != nil {
|
|
return &appError{err, "Record not found", 404}
|
|
}
|
|
if err := viewTemplate.Execute(w, record); err != nil {
|
|
return &appError{err, "Can't display record", 500}
|
|
}
|
|
return nil
|
|
}
|
|
|
|
// STOP OMIT
|
|
|
|
func init() {
|
|
http.Handle("/view", appHandler(viewRecord))
|
|
}
|
|
|
|
type ap struct{}
|
|
|
|
func (ap) NewContext(*http.Request) *ctx { return nil }
|
|
|
|
type ctx struct{}
|
|
|
|
func (*ctx) Errorf(string, ...interface{}) {}
|
|
|
|
var appengine ap
|
|
|
|
type ds struct{}
|
|
|
|
func (ds) NewKey(*ctx, string, string, int, *int) string { return "" }
|
|
func (ds) Get(*ctx, string, *Record) error { return nil }
|
|
|
|
var datastore ds
|
|
|
|
type Record struct{}
|
|
|
|
var viewTemplate *template.Template
|
|
|
|
func main() {}
|