go-tour: fix app engine version, restoring online-specific content

R=minux.ma, campoy, campoy
CC=golang-dev
https://codereview.appspot.com/7195043

appengine/app.yaml → app.yaml

@@ -4,15 +4,14 @@ runtime: go
 api_version: go1
 
 handlers:
-- url: /
-  static_files: static/index.html
-  upload: static/index.html
 - url: /favicon.ico
   static_files: static/favicon.ico
   upload: static/favicon.ico
 - url: /static
   static_dir: static
 - url: /talks
   static_dir: talks
-- url: /(compile|fmt)
+- url: /(|compile|fmt)
   script: _go_app
+
+nobuild_files: (solutions|prog)/.*

gotour/appengine.go

@@ -0,0 +1,92 @@
+// 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.
+
+// +build appengine
+
+package main
+
+import (
+	"bufio"
+	"bytes"
+	"fmt"
+	"io"
+	"net/http"
+
+	"appengine"
+	"appengine/urlfetch"
+)
+
+const runUrl = "http://golang.org/compile"
+
+func init() {
+	http.HandleFunc("/", rootHandler)
+	http.HandleFunc("/compile", compileHandler)
+}
+
+func rootHandler(w http.ResponseWriter, r *http.Request) {
+	c := appengine.NewContext(r)
+	if err := renderTour(w, "."); err != nil {
+		c.Criticalf("template render: %v", err)
+	}
+}
+
+func compileHandler(w http.ResponseWriter, r *http.Request) {
+	if err := passThru(w, r); err != nil {
+		w.WriteHeader(http.StatusInternalServerError)
+		fmt.Fprintln(w, "Compile server error.")
+	}
+}
+
+func passThru(w io.Writer, req *http.Request) error {
+	c := appengine.NewContext(req)
+	client := urlfetch.Client(c)
+	defer req.Body.Close()
+	r, err := client.Post(runUrl, req.Header.Get("Content-type"), req.Body)
+	if err != nil {
+		c.Errorf("making POST request:", err)
+		return err
+	}
+	defer r.Body.Close()
+	if _, err := io.Copy(w, r.Body); err != nil {
+		c.Errorf("copying response Body:", err)
+		return err
+	}
+	return nil
+}
+
+// prepContent returns a Reader that produces the content from the given
+// Reader, but strips the prefix "#appengine: " from each line. It also drops
+// any non-blank like that follows a series of 1 or more lines with the prefix.
+func prepContent(in io.Reader) io.Reader {
+	var prefix = []byte("#appengine: ")
+	out, w := io.Pipe()
+	go func() {
+		r := bufio.NewReader(in)
+		drop := false
+		for {
+			b, err := r.ReadBytes('\n')
+			if err != nil && err != io.EOF {
+				w.CloseWithError(err)
+				return
+			}
+			if bytes.HasPrefix(b, prefix) {
+				b = b[len(prefix):]
+				drop = true
+			} else if drop {
+				if len(b) > 1 {
+					b = nil
+				}
+				drop = false
+			}
+			if len(b) > 0 {
+				w.Write(b)
+			}
+			if err == io.EOF {
+				w.Close()
+				return
+			}
+		}
+	}()
+	return out
+}

gotour/local.go

@@ -2,13 +2,17 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+// +build !appengine
+
 package main
 
 import (
 	"bytes"
+	"encoding/json"
 	"flag"
 	"fmt"
 	"go/build"
+	"io"
 	"io/ioutil"
 	"log"
 	"net"
@@ -41,7 +45,7 @@ var (
 	// a source of numbers, for naming temporary files
 	uniq = make(chan int)
 
-	// GOPATH containing the tour packages 
+	// GOPATH containing the tour packages
 	gopath = os.Getenv("GOPATH")
 )
 
@@ -83,23 +87,23 @@ func main() {
 	}
 
 	log.Println("Serving content from", root)
+
+	fs := http.FileServer(http.Dir(root))
+	http.Handle("/favicon.ico", fs)
+	http.Handle("/static/", fs)
+	http.Handle("/talks/", fs)
+
+	http.HandleFunc("/compile", compileHandler)
+	http.HandleFunc("/kill", killHandler)
 	http.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
-		if r.URL.Path == "/favicon.ico" {
-			fn := filepath.Join(root, "static", r.URL.Path[1:])
-			http.ServeFile(w, r, fn)
-			return
-		} else if r.URL.Path == "/" {
-			err := renderTour(w, root)
-			if err != nil {
+		if r.URL.Path == "/" {
+			if err := renderTour(w, root); err != nil {
 				log.Println(err)
 			}
 			return
 		}
 		http.Error(w, "not found", 404)
 	})
-	http.Handle("/static/", http.FileServer(http.Dir(root)))
-	http.Handle("/talks/", http.FileServer(http.Dir(root)))
-	http.HandleFunc("/kill", kill)
 
 	host, port, err := net.SplitHostPort(*httpListen)
 	if err != nil {
@@ -136,6 +140,28 @@ If you don't understand this message, hit Control-C to terminate this process.
 WARNING!  WARNING!  WARNING!
 `
 
+type response struct {
+	Output string `json:"output"`
+	Errors string `json:"compile_errors"`
+}
+
+func compileHandler(w http.ResponseWriter, req *http.Request) {
+	resp := new(response)
+	out, err := compile(req)
+	if err != nil {
+		if len(out) > 0 {
+			resp.Errors = string(out) + "\n" + err.Error()
+		} else {
+			resp.Errors = err.Error()
+		}
+	} else {
+		resp.Output = string(out)
+	}
+	if err := json.NewEncoder(w).Encode(resp); err != nil {
+		log.Println(err)
+	}
+}
+
 var running struct {
 	sync.Mutex
 	cmd *exec.Cmd
@@ -150,7 +176,7 @@ func stopRun() {
 	running.Unlock()
 }
 
-func kill(w http.ResponseWriter, r *http.Request) {
+func killHandler(w http.ResponseWriter, r *http.Request) {
 	stopRun()
 }
 
@@ -286,3 +312,6 @@ func startBrowser(url string) bool {
 	cmd := exec.Command(args[0], append(args[1:], url)...)
 	return cmd.Start() == nil
 }
+
+// prepContent for the local tour simply returns the content as-is.
+func prepContent(r io.Reader) io.Reader { return r }

gotour/tour.go

@@ -27,7 +27,7 @@ func renderTour(w io.Writer, root string) error {
 		return err
 	}
 	defer f.Close()
-	doc, err := present.Parse(f, source, 0)
+	doc, err := present.Parse(prepContent(f), source, 0)
 	if err != nil {
 		return err
 	}