doc/articles/wiki: fix path handling and clean up test process

Fixes #6525.

R=r
CC=golang-dev
https://golang.org/cl/14383043

doc/articles/wiki/Makefile

@@ -4,17 +4,7 @@
 
 all: index.html
 
-CLEANFILES:=srcextract.bin htmlify.bin get.bin
-
-index.html: wiki.html srcextract.bin htmlify.bin
-	PATH=.:$$PATH awk '/^!/{system(substr($$0,2)); next} {print}' < wiki.html | tr -d '\r' > index.html
-
-test: get.bin
-	bash ./test.sh
-	rm -f get.6 get.bin
-
-%.bin: %.go
-	go build -o $@ $^
+CLEANFILES:=get.bin final-test.bin a.out
 
 clean:
 	rm -f $(CLEANFILES)

doc/articles/wiki/final-noclosure.go

@@ -83,17 +83,15 @@ func renderTemplate(w http.ResponseWriter, tmpl string, p *Page) {
 	}
 }
 
-const lenPath = len("/view/")
+var validPath = regexp.MustCompile("^/(edit|save|view)/([a-zA-Z0-9]+)$")
 
-var titleValidator = regexp.MustCompile("^[a-zA-Z0-9]+$")
-
-func getTitle(w http.ResponseWriter, r *http.Request) (title string, err error) {
-	title = r.URL.Path[lenPath:]
-	if !titleValidator.MatchString(title) {
+func getTitle(w http.ResponseWriter, r *http.Request) (string, error) {
+	m := validPath.FindStringSubmatch(r.URL.Path)
+	if m == nil {
 		http.NotFound(w, r)
-		err = errors.New("Invalid Page Title")
+		return "", errors.New("Invalid Page Title")
 	}
-	return
+	return m[2], nil // The title is the second subexpression.
 }
 
 func main() {

doc/articles/wiki/final-noerror.go

@@ -29,10 +29,8 @@ func loadPage(title string) (*Page, error) {
 	return &Page{Title: title, Body: body}, nil
 }
 
-const lenPath = len("/view/")
-
 func editHandler(w http.ResponseWriter, r *http.Request) {
-	title := r.URL.Path[lenPath:]
+	title := r.URL.Path[len("/edit/"):]
 	p, err := loadPage(title)
 	if err != nil {
 		p = &Page{Title: title}
@@ -42,7 +40,7 @@ func editHandler(w http.ResponseWriter, r *http.Request) {
 }
 
 func viewHandler(w http.ResponseWriter, r *http.Request) {
-	title := r.URL.Path[lenPath:]
+	title := r.URL.Path[len("/view/"):]
 	p, _ := loadPage(title)
 	t, _ := template.ParseFiles("view.html")
 	t.Execute(w, p)

doc/articles/wiki/final-parsetemplate.go

@@ -70,18 +70,16 @@ func renderTemplate(w http.ResponseWriter, tmpl string, p *Page) {
 	}
 }
 
-const lenPath = len("/view/")
-
-var titleValidator = regexp.MustCompile("^[a-zA-Z0-9]+$")
+var validPath = regexp.MustCompile("^/(edit|save|view)/([a-zA-Z0-9]+)$")
 
 func makeHandler(fn func(http.ResponseWriter, *http.Request, string)) http.HandlerFunc {
 	return func(w http.ResponseWriter, r *http.Request) {
-		title := r.URL.Path[lenPath:]
-		if !titleValidator.MatchString(title) {
+		m := validPath.FindStringSubmatch(r.URL.Path)
+		if m == nil {
 			http.NotFound(w, r)
 			return
 		}
-		fn(w, r, title)
+		fn(w, r, m[2])
 	}
 }
 

doc/articles/wiki/final-template.go

@@ -29,10 +29,8 @@ func loadPage(title string) (*Page, error) {
 	return &Page{Title: title, Body: body}, nil
 }
 
-const lenPath = len("/view/")
-
 func editHandler(w http.ResponseWriter, r *http.Request) {
-	title := r.URL.Path[lenPath:]
+	title := r.URL.Path[len("/edit/"):]
 	p, err := loadPage(title)
 	if err != nil {
 		p = &Page{Title: title}
@@ -41,13 +39,13 @@ func editHandler(w http.ResponseWriter, r *http.Request) {
 }
 
 func viewHandler(w http.ResponseWriter, r *http.Request) {
-	title := r.URL.Path[lenPath:]
+	title := r.URL.Path[len("/view/"):]
 	p, _ := loadPage(title)
 	renderTemplate(w, "view", p)
 }
 
 func saveHandler(w http.ResponseWriter, r *http.Request) {
-	title := r.URL.Path[lenPath:]
+	title := r.URL.Path[len("/save/"):]
 	body := r.FormValue("body")
 	p := &Page{Title: title, Body: []byte(body)}
 	p.save()

doc/articles/wiki/final.go

@@ -67,18 +67,16 @@ func renderTemplate(w http.ResponseWriter, tmpl string, p *Page) {
 	}
 }
 
-const lenPath = len("/view/")
-
-var titleValidator = regexp.MustCompile("^[a-zA-Z0-9]+$")
+var validPath = regexp.MustCompile("^/(edit|save|view)/([a-zA-Z0-9]+)$")
 
 func makeHandler(fn func(http.ResponseWriter, *http.Request, string)) http.HandlerFunc {
 	return func(w http.ResponseWriter, r *http.Request) {
-		title := r.URL.Path[lenPath:]
-		if !titleValidator.MatchString(title) {
+		m := validPath.FindStringSubmatch(r.URL.Path)
+		if m == nil {
 			http.NotFound(w, r)
 			return
 		}
-		fn(w, r, title)
+		fn(w, r, m[2])
 	}
 }
 

doc/articles/wiki/htmlify.go

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

doc/articles/wiki/index.html

@@ -260,18 +260,15 @@ Let's create a handler, <code>viewHandler</code> that will allow users to
 view a wiki page. It will handle URLs prefixed with "/view/".
 </p>
 
-{{code "doc/articles/wiki/part2.go" `/^const lenPath/`}}
-
 {{code "doc/articles/wiki/part2.go" `/^func viewHandler/` `/^}/`}}
 
 <p>
 First, this function extracts the page title from <code>r.URL.Path</code>,
-the path component of the request URL. The global constant
-<code>lenPath</code> is the length of the leading <code>"/view/"</code>
-component of the request path.
-The <code>Path</code> is re-sliced with <code>[lenPath:]</code> to drop the
-first 6 characters of the string. This is because the path will invariably
-begin with <code>"/view/"</code>, which is not part of the page's title.
+the path component of the request URL.
+The <code>Path</code> is re-sliced with <code>[len("/view/"):]</code> to drop
+the leading <code>"/view/"</code> component of the request path.
+This is because the path will invariably begin with <code>"/view/"</code>,
+which is not part of the page's title.
 </p>
 
 <p>
@@ -431,6 +428,11 @@ to its own function:
 </p>
 
 {{code "doc/articles/wiki/final-template.go" `/^func renderTemplate/` `/^}/`}}
+
+<p>
+And modify the handlers to use that function:
+</p>
+
 {{code "doc/articles/wiki/final-template.go" `/^func viewHandler/` `/^}/`}}
 {{code "doc/articles/wiki/final-template.go" `/^func editHandler/` `/^}/`}}
 
@@ -573,10 +575,11 @@ this, we can write a function to validate the title with a regular expression.
 
 <p>
 First, add <code>"regexp"</code> to the <code>import</code> list.
-Then we can create a global variable to store our validation regexp:
+Then we can create a global variable to store our validation 
+expression:
 </p>
 
-{{code "doc/articles/wiki/final-noclosure.go" `/^var titleValidator/`}}
+{{code "doc/articles/wiki/final-noclosure.go" `/^var validPath/`}}
 
 <p>
 The function <code>regexp.MustCompile</code> will parse and compile the
@@ -587,9 +590,8 @@ an <code>error</code> as a second parameter.
 </p>
 
 <p>
-Now, let's write a function, <code>getTitle</code>, that extracts the title
-string from the request URL, and tests it against our
-<code>TitleValidator</code> expression:
+Now, let's write a function that uses the <code>validPath</code>
+expression to validate path and extract the page title:
 </p>
 
 {{code "doc/articles/wiki/final-noclosure.go" `/func getTitle/` `/^}/`}}

doc/articles/wiki/notemplate.go

@@ -29,16 +29,14 @@ func loadPage(title string) (*Page, error) {
 	return &Page{Title: title, Body: body}, nil
 }
 
-const lenPath = len("/view/")
-
 func viewHandler(w http.ResponseWriter, r *http.Request) {
-	title := r.URL.Path[lenPath:]
+	title := r.URL.Path[len("/view/"):]
 	p, _ := loadPage(title)
 	fmt.Fprintf(w, "<h1>%s</h1><div>%s</div>", p.Title, p.Body)
 }
 
 func editHandler(w http.ResponseWriter, r *http.Request) {
-	title := r.URL.Path[lenPath:]
+	title := r.URL.Path[len("/edit/"):]
 	p, err := loadPage(title)
 	if err != nil {
 		p = &Page{Title: title}

doc/articles/wiki/part2.go

@@ -29,10 +29,8 @@ func loadPage(title string) (*Page, error) {
 	return &Page{Title: title, Body: body}, nil
 }
 
-const lenPath = len("/view/")
-
 func viewHandler(w http.ResponseWriter, r *http.Request) {
-	title := r.URL.Path[lenPath:]
+	title := r.URL.Path[len("/view/"):]
 	p, _ := loadPage(title)
 	fmt.Fprintf(w, "<h1>%s</h1><div>%s</div>", p.Title, p.Body)
 }

doc/articles/wiki/part3-errorhandling.go

@@ -29,15 +29,13 @@ func loadPage(title string) (*Page, error) {
 	return &Page{Title: title, Body: body}, nil
 }
 
-const lenPath = len("/view/")
-
 func renderTemplate(w http.ResponseWriter, tmpl string, p *Page) {
 	t, _ := template.ParseFiles(tmpl + ".html")
 	t.Execute(w, p)
 }
 
 func viewHandler(w http.ResponseWriter, r *http.Request) {
-	title := r.URL.Path[lenPath:]
+	title := r.URL.Path[len("/view/"):]
 	p, err := loadPage(title)
 	if err != nil {
 		http.Redirect(w, r, "/edit/"+title, http.StatusFound)
@@ -47,7 +45,7 @@ func viewHandler(w http.ResponseWriter, r *http.Request) {
 }
 
 func editHandler(w http.ResponseWriter, r *http.Request) {
-	title := r.URL.Path[lenPath:]
+	title := r.URL.Path[len("/edit/"):]
 	p, err := loadPage(title)
 	if err != nil {
 		p = &Page{Title: title}
@@ -56,7 +54,7 @@ func editHandler(w http.ResponseWriter, r *http.Request) {
 }
 
 func saveHandler(w http.ResponseWriter, r *http.Request) {
-	title := r.URL.Path[lenPath:]
+	title := r.URL.Path[len("/save/"):]
 	body := r.FormValue("body")
 	p := &Page{Title: title, Body: []byte(body)}
 	err := p.save()

doc/articles/wiki/part3.go

@@ -29,21 +29,19 @@ func loadPage(title string) (*Page, error) {
 	return &Page{Title: title, Body: body}, nil
 }
 
-const lenPath = len("/view/")
-
 func renderTemplate(w http.ResponseWriter, tmpl string, p *Page) {
 	t, _ := template.ParseFiles(tmpl + ".html")
 	t.Execute(w, p)
 }
 
 func viewHandler(w http.ResponseWriter, r *http.Request) {
-	title := r.URL.Path[lenPath:]
+	title := r.URL.Path[len("/view/"):]
 	p, _ := loadPage(title)
 	renderTemplate(w, "view", p)
 }
 
 func editHandler(w http.ResponseWriter, r *http.Request) {
-	title := r.URL.Path[lenPath:]
+	title := r.URL.Path[len("/edit/"):]
 	p, err := loadPage(title)
 	if err != nil {
 		p = &Page{Title: title}

doc/articles/wiki/srcextract.go

-// 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.
-
-package main
-
-import (
-	"bytes"
-	"flag"
-	"go/ast"
-	"go/parser"
-	"go/printer"
-	"go/token"
-	"log"
-	"os"
-	"text/template"
-)
-
-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
-	fs := token.NewFileSet()
-	file, err := parser.ParseFile(fs, *srcFn, nil, 0)
-	if err != nil {
-		log.Fatal(err)
-	}
-	// create filter
-	filter := func(name string) bool {
-		return name == *getName
-	}
-	// filter
-	if !ast.FilterFile(file, filter) {
-		os.Exit(1)
-	}
-	// print the AST
-	var b bytes.Buffer
-	printer.Fprint(&b, fs, 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
-	if *html {
-		template.HTMLEscape(os.Stdout, b.Bytes())
-	} else {
-		b.WriteTo(os.Stdout)
-	}
-}

doc/articles/wiki/test.bash

@@ -7,10 +7,17 @@ set -e
 wiki_pid=
 cleanup() {
 	kill $wiki_pid
-	rm -f test_*.out Test.txt final-test.bin final-test.go
+	rm -f test_*.out Test.txt final-test.bin final-test.go a.out get.bin
 }
 trap cleanup 0 INT
 
+# If called with -all, check that all code snippets compile.
+if [ "$1" == "-all" ]; then
+	for fn in *.go; do
+		go build -o a.out $fn
+	done
+fi
+
 go build -o get.bin get.go
 addr=$(./get.bin -addr)
 sed s/:8080/$addr/ < final.go > final-test.go