Wiki codelab, complete with tests.

R=r, rsc, gri
CC=golang-dev
https://golang.org/cl/887045

doc/codelab/wiki/Makefile

+# Copyright 2010 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.
+
+include ../../../src/Make.$(GOARCH)
+
+all: index.html
+
+# ugly hack to deal with whitespaces in $GOROOT
+nullstring :=
+space := $(nullstring) # a space at the end
+QUOTED_GOROOT:=$(subst $(space),\ ,$(GOROOT))
+
+include $(QUOTED_GOROOT)/src/Make.common
+
+CLEANFILES+=index.html srcextract.bin htmlify.bin
+
+index.html: srcextract.bin htmlify.bin
+	awk '/^!/{system(substr($$0,2)); next} {print}' "$$@" < wiki.html > index.html
+
+test: final.bin
+	./test.sh
+	rm -f final.6 final.bin
+
+%.bin: %.$O
+	$(QUOTED_GOBIN)/$(LD) -o $@ $<
+%.$O: 
+	$(QUOTED_GOBIN)/$(GC) $*.go
+

doc/codelab/wiki/edit.html

+<h1>Editing {title}</h1>
+
+<form action="/save/{title}" method="POST">
+<div><textarea name="body" rows="20" cols="80">{body|html}</textarea></div>
+<div><input type="submit" value="Save"></div>
+</form>

doc/codelab/wiki/final-noclosure.go

+package main
+
+import (
+	"http"
+	"io/ioutil"
+	"os"
+	"regexp"
+	"template"
+)
+
+type page struct {
+	title string
+	body  []byte
+}
+
+func (p *page) save() os.Error {
+	filename := p.title + ".txt"
+	return ioutil.WriteFile(filename, p.body, 0600)
+}
+
+func loadPage(title string) (*page, os.Error) {
+	filename := title + ".txt"
+	body, err := ioutil.ReadFile(filename)
+	if err != nil {
+		return nil, err
+	}
+	return &page{title: title, body: body}, nil
+}
+
+func viewHandler(c *http.Conn, r *http.Request) {
+	title, err := getTitle(c, r)
+	if err != nil {
+		return
+	}
+	p, err := loadPage(title)
+	if err != nil {
+		http.Redirect(c, "/edit/"+title, http.StatusFound)
+		return
+	}
+	renderTemplate(c, "view", p)
+}
+
+func editHandler(c *http.Conn, r *http.Request) {
+	title, err := getTitle(c, r)
+	if err != nil {
+		return
+	}
+	p, err := loadPage(title)
+	if err != nil {
+		p = &page{title: title}
+	}
+	renderTemplate(c, "edit", p)
+}
+
+func saveHandler(c *http.Conn, r *http.Request) {
+	title, err := getTitle(c, r)
+	if err != nil {
+		return
+	}
+	body := r.FormValue("body")
+	p := &page{title: title, body: []byte(body)}
+	err = p.save()
+	if err != nil {
+		http.Error(c, err.String(), http.StatusInternalServerError)
+		return
+	}
+	http.Redirect(c, "/view/"+title, http.StatusFound)
+}
+
+func renderTemplate(c *http.Conn, tmpl string, p *page) {
+	t, err := template.ParseFile(tmpl+".html", nil)
+	if err != nil {
+		http.Error(c, err.String(), http.StatusInternalServerError)
+		return
+	}
+	err = t.Execute(p, c)
+	if err != nil {
+		http.Error(c, err.String(), http.StatusInternalServerError)
+	}
+}
+
+const lenPath = len("/view/")
+
+var titleValidator = regexp.MustCompile("^[a-zA-Z0-9]+$")
+
+func getTitle(c *http.Conn, r *http.Request) (title string, err os.Error) {
+	title = r.URL.Path[lenPath:]
+	if !titleValidator.MatchString(title) {
+		http.NotFound(c, r)
+		err = os.NewError("Invalid Page Title")
+	}
+	return
+}
+
+func main() {
+	http.HandleFunc("/view/", viewHandler)
+	http.HandleFunc("/edit/", editHandler)
+	http.HandleFunc("/save/", saveHandler)
+	http.ListenAndServe(":8080", nil)
+}

doc/codelab/wiki/final-noerror.go

+package main
+
+import (
+	"http"
+	"io/ioutil"
+	"os"
+	"template"
+)
+
+type page struct {
+	title string
+	body  []byte
+}
+
+func (p *page) save() os.Error {
+	filename := p.title + ".txt"
+	return ioutil.WriteFile(filename, p.body, 0600)
+}
+
+func loadPage(title string) (*page, os.Error) {
+	filename := title + ".txt"
+	body, err := ioutil.ReadFile(filename)
+	if err != nil {
+		return nil, err
+	}
+	return &page{title: title, body: body}, nil
+}
+
+const lenPath = len("/view/")
+
+func editHandler(c *http.Conn, r *http.Request) {
+	title := r.URL.Path[lenPath:]
+	p, err := loadPage(title)
+	if err != nil {
+		p = &page{title: title}
+	}
+	t, _ := template.ParseFile("edit.html", nil)
+	t.Execute(p, c)
+}
+
+func viewHandler(c *http.Conn, r *http.Request) {
+	title := r.URL.Path[lenPath:]
+	p, _ := loadPage(title)
+	t, _ := template.ParseFile("view.html", nil)
+	t.Execute(p, c)
+}
+
+func main() {
+	http.HandleFunc("/view/", viewHandler)
+	http.HandleFunc("/edit/", editHandler)
+	http.ListenAndServe(":8080", nil)
+}

doc/codelab/wiki/final-parsetemplate.go

+package main
+
+import (
+	"http"
+	"io/ioutil"
+	"os"
+	"regexp"
+	"template"
+)
+
+type page struct {
+	title string
+	body  []byte
+}
+
+func (p *page) save() os.Error {
+	filename := p.title + ".txt"
+	return ioutil.WriteFile(filename, p.body, 0600)
+}
+
+func loadPage(title string) (*page, os.Error) {
+	filename := title + ".txt"
+	body, err := ioutil.ReadFile(filename)
+	if err != nil {
+		return nil, err
+	}
+	return &page{title: title, body: body}, nil
+}
+
+func viewHandler(c *http.Conn, r *http.Request, title string) {
+	p, err := loadPage(title)
+	if err != nil {
+		http.Redirect(c, "/edit/"+title, http.StatusFound)
+		return
+	}
+	renderTemplate(c, "view", p)
+}
+
+func editHandler(c *http.Conn, r *http.Request, title string) {
+	p, err := loadPage(title)
+	if err != nil {
+		p = &page{title: title}
+	}
+	renderTemplate(c, "edit", p)
+}
+
+func saveHandler(c *http.Conn, r *http.Request, title string) {
+	body := r.FormValue("body")
+	p := &page{title: title, body: []byte(body)}
+	err := p.save()
+	if err != nil {
+		http.Error(c, err.String(), http.StatusInternalServerError)
+		return
+	}
+	http.Redirect(c, "/view/"+title, http.StatusFound)
+}
+
+func renderTemplate(c *http.Conn, tmpl string, p *page) {
+	t, err := template.ParseFile(tmpl+".html", nil)
+	if err != nil {
+		http.Error(c, err.String(), http.StatusInternalServerError)
+		return
+	}
+	err = t.Execute(p, c)
+	if err != nil {
+		http.Error(c, err.String(), http.StatusInternalServerError)
+	}
+}
+
+const lenPath = len("/view/")
+
+var titleValidator = regexp.MustCompile("^[a-zA-Z0-9]+$")
+
+func makeHandler(fn func(*http.Conn, *http.Request, string)) http.HandlerFunc {
+	return func(c *http.Conn, r *http.Request) {
+		title := r.URL.Path[lenPath:]
+		if !titleValidator.MatchString(title) {
+			http.NotFound(c, r)
+			return
+		}
+		fn(c, r, title)
+	}
+}
+
+func main() {
+	http.HandleFunc("/view/", makeHandler(viewHandler))
+	http.HandleFunc("/edit/", makeHandler(editHandler))
+	http.HandleFunc("/save/", makeHandler(saveHandler))
+	http.ListenAndServe(":8080", nil)
+}

doc/codelab/wiki/final-template.go

+package main
+
+import (
+	"http"
+	"io/ioutil"
+	"os"
+	"template"
+)
+
+type page struct {
+	title string
+	body  []byte
+}
+
+func (p *page) save() os.Error {
+	filename := p.title + ".txt"
+	return ioutil.WriteFile(filename, p.body, 0600)
+}
+
+func loadPage(title string) (*page, os.Error) {
+	filename := title + ".txt"
+	body, err := ioutil.ReadFile(filename)
+	if err != nil {
+		return nil, err
+	}
+	return &page{title: title, body: body}, nil
+}
+
+const lenPath = len("/view/")
+
+func editHandler(c *http.Conn, r *http.Request) {
+	title := r.URL.Path[lenPath:]
+	p, err := loadPage(title)
+	if err != nil {
+		p = &page{title: title}
+	}
+	renderTemplate(c, "view", p)
+}
+
+func viewHandler(c *http.Conn, r *http.Request) {
+	title := r.URL.Path[lenPath:]
+	p, _ := loadPage(title)
+	renderTemplate(c, "edit", p)
+}
+
+func saveHandler(c *http.Conn, r *http.Request) {
+	title := r.URL.Path[lenPath:]
+	body := r.FormValue("body")
+	p := &page{title: title, body: []byte(body)}
+	p.save()
+	http.Redirect(c, "/view/"+title, http.StatusFound)
+}
+
+func renderTemplate(c *http.Conn, tmpl string, p *page) {
+	t, _ := template.ParseFile(tmpl+".html", nil)
+	t.Execute(p, c)
+}
+
+func main() {
+	http.HandleFunc("/view/", viewHandler)
+	http.HandleFunc("/edit/", editHandler)
+	http.HandleFunc("/save/", saveHandler)
+	http.ListenAndServe(":8080", nil)
+}

doc/codelab/wiki/final.go

+package main
+
+import (
+	"http"
+	"io/ioutil"
+	"os"
+	"regexp"
+	"template"
+)
+
+type page struct {
+	title string
+	body  []byte
+}
+
+func (p *page) save() os.Error {
+	filename := p.title + ".txt"
+	return ioutil.WriteFile(filename, p.body, 0600)
+}
+
+func loadPage(title string) (*page, os.Error) {
+	filename := title + ".txt"
+	body, err := ioutil.ReadFile(filename)
+	if err != nil {
+		return nil, err
+	}
+	return &page{title: title, body: body}, nil
+}
+
+func viewHandler(c *http.Conn, r *http.Request, title string) {
+	p, err := loadPage(title)
+	if err != nil {
+		http.Redirect(c, "/edit/"+title, http.StatusFound)
+		return
+	}
+	renderTemplate(c, "view", p)
+}
+
+func editHandler(c *http.Conn, r *http.Request, title string) {
+	p, err := loadPage(title)
+	if err != nil {
+		p = &page{title: title}
+	}
+	renderTemplate(c, "edit", p)
+}
+
+func saveHandler(c *http.Conn, r *http.Request, title string) {
+	body := r.FormValue("body")
+	p := &page{title: title, body: []byte(body)}
+	err := p.save()
+	if err != nil {
+		http.Error(c, err.String(), http.StatusInternalServerError)
+		return
+	}
+	http.Redirect(c, "/view/"+title, http.StatusFound)
+}
+
+var templates = make(map[string]*template.Template)
+
+func init() {
+	for _, tmpl := range []string{"edit", "view"} {
+		templates[tmpl] = template.MustParseFile(tmpl+".html", nil)
+	}
+}
+
+func renderTemplate(c *http.Conn, tmpl string, p *page) {
+	err := templates[tmpl].Execute(p, c)
+	if err != nil {
+		http.Error(c, err.String(), http.StatusInternalServerError)
+	}
+}
+
+const lenPath = len("/view/")
+
+var titleValidator = regexp.MustCompile("^[a-zA-Z0-9]+$")
+
+func makeHandler(fn func(*http.Conn, *http.Request, string)) http.HandlerFunc {
+	return func(c *http.Conn, r *http.Request) {
+		title := r.URL.Path[lenPath:]
+		if !titleValidator.MatchString(title) {
+			http.NotFound(c, r)
+			return
+		}
+		fn(c, r, title)
+	}
+}
+
+func main() {
+	http.HandleFunc("/view/", makeHandler(viewHandler))
+	http.HandleFunc("/edit/", makeHandler(editHandler))
+	http.HandleFunc("/save/", makeHandler(saveHandler))
+	http.ListenAndServe(":8080", nil)
+}

doc/codelab/wiki/htmlify.go

+package main
+
+import (
+	"os"
+	"template"
+	"io/ioutil"
+)
+
+func main() {
+	b, _ := ioutil.ReadAll(os.Stdin)
+	template.HTMLFormatter(os.Stdout, b, "")
+}

doc/codelab/wiki/http-sample.go

+package main
+
+import (
+	"fmt"
+	"http"
+)
+
+func handler(c *http.Conn, r *http.Request) {
+	fmt.Fprintf(c, "Hi there, I love %s!", r.URL.Path[1:])
+}
+
+func main() {
+	http.HandleFunc("/", handler)
+	http.ListenAndServe(":8080", nil)
+}

doc/codelab/wiki/notemplate.go

+package main
+
+import (
+	"fmt"
+	"http"
+	"io/ioutil"
+	"os"
+)
+
+type page struct {
+	title string
+	body  []byte
+}
+
+func (p *page) save() os.Error {
+	filename := p.title + ".txt"
+	return ioutil.WriteFile(filename, p.body, 0600)
+}
+
+func loadPage(title string) (*page, os.Error) {
+	filename := title + ".txt"
+	body, err := ioutil.ReadFile(filename)
+	if err != nil {
+		return nil, err
+	}
+	return &page{title: title, body: body}, nil
+}
+
+const lenPath = len("/view/")
+
+func viewHandler(c *http.Conn, r *http.Request) {
+	title := r.URL.Path[lenPath:]
+	p, _ := loadPage(title)
+	fmt.Fprintf(c, "<h1>%s</h1><div>%s</div>", p.title, p.body)
+}
+
+func editHandler(c *http.Conn, r *http.Request) {
+	title := r.URL.Path[lenPath:]
+	p, err := loadPage(title)
+	if err != nil {
+		p = &page{title: title}
+	}
+	fmt.Fprintf(c, "<h1>Editing %s</h1>"+
+		"<form action=\"/save/%s\" method=\"POST\">"+
+		"<textarea name=\"body\">%s</textarea><br>"+
+		"<input type=\"submit\" value=\"Save\">"+
+		"</form>",
+		p.title, p.title, p.body)
+}
+
+func main() {
+	http.HandleFunc("/view/", viewHandler)
+	http.HandleFunc("/edit/", editHandler)
+	http.ListenAndServe(":8080", nil)
+}

doc/codelab/wiki/part1-noerror.go

+package main
+
+import (
+	"fmt"
+	"io/ioutil"
+	"os"
+)
+
+type page struct {
+	title string
+	body  []byte
+}
+
+func (p *page) save() os.Error {
+	filename := p.title + ".txt"
+	return ioutil.WriteFile(filename, p.body, 0600)
+}
+
+func loadPage(title string) *page {
+	filename := title + ".txt"
+	body, _ := ioutil.ReadFile(filename)
+	return &page{title: title, body: body}
+}
+
+func main() {
+	p1 := &page{title: "TestPage", body: []byte("This is a sample page.")}
+	p1.save()
+	p2 := loadPage("TestPage")
+	fmt.Println(string(p2.body))
+}

doc/codelab/wiki/part1.go

+package main
+
+import (
+	"fmt"
+	"io/ioutil"
+	"os"
+)
+
+type page struct {
+	title string
+	body  []byte
+}
+
+func (p *page) save() os.Error {
+	filename := p.title + ".txt"
+	return ioutil.WriteFile(filename, p.body, 0600)
+}
+
+func loadPage(title string) (*page, os.Error) {
+	filename := title + ".txt"
+	body, err := ioutil.ReadFile(filename)
+	if err != nil {
+		return nil, err
+	}
+	return &page{title: title, body: body}, nil
+}
+
+func main() {
+	p1 := &page{title: "TestPage", body: []byte("This is a sample page.")}
+	p1.save()
+	p2, _ := loadPage("TestPage")
+	fmt.Println(string(p2.body))
+}

doc/codelab/wiki/part2.go

+package main
+
+import (
+	"fmt"
+	"http"
+	"io/ioutil"
+	"os"
+)
+
+type page struct {
+	title string
+	body  []byte
+}
+
+func (p *page) save() os.Error {
+	filename := p.title + ".txt"
+	return ioutil.WriteFile(filename, p.body, 0600)
+}
+
+func loadPage(title string) (*page, os.Error) {
+	filename := title + ".txt"
+	body, err := ioutil.ReadFile(filename)
+	if err != nil {
+		return nil, err
+	}
+	return &page{title: title, body: body}, nil
+}
+
+const lenPath = len("/view/")
+
+func viewHandler(c *http.Conn, r *http.Request) {
+	title := r.URL.Path[lenPath:]
+	p, _ := loadPage(title)
+	fmt.Fprintf(c, "<h1>%s</h1><div>%s</div>", p.title, p.body)
+}
+
+func main() {
+	http.HandleFunc("/view/", viewHandler)
+	http.ListenAndServe(":8080", nil)
+}

doc/codelab/wiki/srcextract.go

+package main
+
+import (
+	"bytes"
+	"flag"
+	"go/parser"
+	"go/printer"
+	"go/ast"
+	"log"
+	"os"
+)
+
+var (
+	srcFn   = flag.String("src", "", "source filename")
+	getName = flag.String("name", "", "func/type name to output")
+	html    = flag.Bool("html", true, "output HTML")
+	showPkg = flag.Bool("pkg", false, "show package in output")
+)
+
+func main() {
+	// handle input
+	flag.Parse()
+	if *srcFn == "" || *getName == "" {
+		flag.Usage()
+		os.Exit(2)
+	}
+	// load file
+	file, err := parser.ParseFile(*srcFn, nil, nil, 0)
+	if err != nil {
+		log.Exit(err)
+	}
+	// create printer
+	p := &printer.Config{
+		Mode:     0,
+		Tabwidth: 8,
+		Styler:   nil,
+	}
+	if *html {
+		p.Mode = printer.GenHTML
+	}
+	// create filter
+	filter := func(name string) bool {
+		return name == *getName
+	}
+	// filter
+	if !ast.FilterFile(file, filter) {
+		os.Exit(1)
+	}
+	b := new(bytes.Buffer)
+	p.Fprint(b, file)
+	// drop package declaration
+	if !*showPkg {
+		for {
+			c, err := b.ReadByte()
+			if c == '\n' || err != nil {
+				break
+			}
+		}
+	}
+	// drop leading newlines
+	for {
+		b, err := b.ReadByte()
+		if err != nil {
+			break
+		}
+		if b != '\n' {
+			os.Stdout.Write([]byte{b})
+			break
+		}
+	}
+	// output
+	b.WriteTo(os.Stdout)
+}

doc/codelab/wiki/test.sh

+#1/bin/bash
+
+./final.bin &
+wiki_pid=$!
+
+cleanup() {
+	kill $wiki_pid
+	rm -f test_*.out Test.txt
+	exit ${1:-1}
+}
+trap cleanup INT
+
+sleep 1
+
+curl -s -o test_edit.out http://localhost:8080/edit/Test 
+cmp test_edit.out test_edit.good || cleanup 1
+curl -s -o /dev/null -d body=some%20content http://localhost:8080/save/Test
+cmp Test.txt test_Test.txt.good || cleanup 1
+curl -s -o test_view.out http://localhost:8080/view/Test
+cmp test_view.out test_view.good || cleanup 1
+
+echo "Passed"
+cleanup 0
+

doc/codelab/wiki/test_Test.txt.good

+some content
\ No newline at end of file

doc/codelab/wiki/test_edit.good

+<h1>Editing Test</h1>
+
+<form action="/save/Test" method="POST">
+<div><textarea name="body" rows="20" cols="80"></textarea></div>
+<div><input type="submit" value="Save"></div>
+</form>

doc/codelab/wiki/test_view.good

+<h1>Test</h1>
+
+<p>[<a href="/edit/Test">edit</a>]</p>
+
+<div>some content</div>

doc/codelab/wiki/view.html

+<h1>{title}</h1>
+
+<p>[<a href="/edit/{title}">edit</a>]</p>
+
+<div>{body}</div>