godoc: hide and block share functionality from specific countries

This will permit us to serve *.golang.org to Chinese users.

Change-Id: I5217753aa67931522c7e6be106477534c99a20b2
Reviewed-on: https://go-review.googlesource.com/14194
Reviewed-by: Andrew Gerrand <adg@golang.org>

godoc/appengine.go

@@ -0,0 +1,13 @@
+// Copyright 2015 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 godoc
+
+import "appengine"
+
+func init() {
+	onAppengine = !appengine.IsDevAppServer()
+}

godoc/godoc.go

@@ -281,6 +281,7 @@ func sanitizeFunc(src string) string {
 type PageInfo struct {
 	Dirname string // directory containing the package
 	Err     error  // error or nil
+	Share   bool   // show share button on examples
 
 	// package info
 	FSet       *token.FileSet         // nil if no package documentation
@@ -490,7 +491,8 @@ func (p *Presentation) example_htmlFunc(info *PageInfo, funcName string) string
 
 		err := p.ExampleHTML.Execute(&buf, struct {
 			Name, Doc, Code, Play, Output string
-		}{eg.Name, eg.Doc, code, play, out})
+			Share                         bool
+		}{eg.Name, eg.Doc, code, play, out, info.Share})
 		if err != nil {
 			log.Print(err)
 		}

godoc/page.go

@@ -16,6 +16,7 @@ type Page struct {
 	Subtitle string
 	Query    string
 	Body     []byte
+	Share    bool
 
 	// filled in by servePage
 	SearchBox  bool
@@ -39,5 +40,19 @@ func (p *Presentation) ServeError(w http.ResponseWriter, r *http.Request, relpat
 		Title:    "File " + relpath,
 		Subtitle: relpath,
 		Body:     applyTemplate(p.ErrorHTML, "errorHTML", err), // err may contain an absolute path!
+		Share:    allowShare(r),
 	})
 }
+
+var onAppengine = false // overriden in appengine.go when on app engine
+
+func allowShare(r *http.Request) bool {
+	if !onAppengine {
+		return true
+	}
+	switch r.Header.Get("X-AppEngine-Country") {
+	case "", "ZZ", "HK", "CN", "RC":
+		return false
+	}
+	return true
+}

godoc/search.go

@@ -126,6 +126,7 @@ func (p *Presentation) HandleSearch(w http.ResponseWriter, r *http.Request) {
 		Tabtitle: query,
 		Query:    query,
 		Body:     body.Bytes(),
+		Share:    allowShare(r),
 	})
 }
 

godoc/server.go

@@ -300,11 +300,13 @@ func (h *handlerServer) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 		info.TypeInfoIndex[ti.Name] = i
 	}
 
+	info.Share = allowShare(r)
 	h.p.ServePage(w, Page{
 		Title:    title,
 		Tabtitle: tabtitle,
 		Subtitle: subtitle,
 		Body:     applyTemplate(h.p.PackageHTML, "packageHTML", info),
+		Share:    info.Share,
 	})
 }
 
@@ -546,6 +548,7 @@ func (p *Presentation) serveTextFile(w http.ResponseWriter, r *http.Request, abs
 		Title:    title + " " + relpath,
 		Tabtitle: relpath,
 		Body:     buf.Bytes(),
+		Share:    allowShare(r),
 	})
 }
 
@@ -606,6 +609,7 @@ func (p *Presentation) serveDirectory(w http.ResponseWriter, r *http.Request, ab
 		Title:    "Directory " + relpath,
 		Tabtitle: relpath,
 		Body:     applyTemplate(p.DirlistHTML, "dirlistHTML", list),
+		Share:    allowShare(r),
 	})
 }
 
@@ -631,6 +635,12 @@ func (p *Presentation) ServeHTMLDoc(w http.ResponseWriter, r *http.Request, absp
 		log.Printf("decoding metadata %s: %v", relpath, err)
 	}
 
+	page := Page{
+		Title:    meta.Title,
+		Subtitle: meta.Subtitle,
+		Share:    allowShare(r),
+	}
+
 	// evaluate as template if indicated
 	if meta.Template {
 		tmpl, err := template.New("main").Funcs(p.TemplateFuncs()).Parse(string(src))
@@ -640,7 +650,7 @@ func (p *Presentation) ServeHTMLDoc(w http.ResponseWriter, r *http.Request, absp
 			return
 		}
 		var buf bytes.Buffer
-		if err := tmpl.Execute(&buf, nil); err != nil {
+		if err := tmpl.Execute(&buf, page); err != nil {
 			log.Printf("executing template %s: %v", relpath, err)
 			p.ServeError(w, r, relpath, err)
 			return
@@ -655,11 +665,8 @@ func (p *Presentation) ServeHTMLDoc(w http.ResponseWriter, r *http.Request, absp
 		src = buf.Bytes()
 	}
 
-	p.ServePage(w, Page{
+	page.Body = src
-		Title:    meta.Title,
+	p.ServePage(w, page)
-		Subtitle: meta.Subtitle,
-		Body:     src,
-	})
 }
 
 func (p *Presentation) ServeFile(w http.ResponseWriter, r *http.Request) {

godoc/static/example.html

@@ -13,7 +13,9 @@
 				<div class="buttons">
 					<a class="run" title="Run this code [shift-enter]">Run</a>
 					<a class="fmt" title="Format this code">Format</a>
+					{{if $.Share}}
 					<a class="share" title="Share this code">Share</a>
+					{{end}}
 				</div>
 			</div>
 		{{else}}

godoc/static/godoc.html

@@ -55,7 +55,9 @@ func main() {
 	<div class="buttons">
 		<a class="run" title="Run this code [shift-enter]">Run</a>
 		<a class="fmt" title="Format this code">Format</a>
+		{{if $.Share}}
 		<a class="share" title="Share this code">Share</a>
+		{{end}}
 	</div>
 </div>
 {{end}}

godoc/static/static.go

@@ -441,7 +441,9 @@ var Files = map[string]string{
 				<div class="buttons">
 					<a class="run" title="Run this code [shift-enter]">Run</a>
 					<a class="fmt" title="Format this code">Format</a>
+					{{if $.Share}}
 					<a class="share" title="Share this code">Share</a>
+					{{end}}
 				</div>
 			</div>
 		{{else}}
@@ -513,7 +515,9 @@ func main() {
 	<div class="buttons">
 		<a class="run" title="Run this code [shift-enter]">Run</a>
 		<a class="fmt" title="Format this code">Format</a>
+		{{if $.Share}}
 		<a class="share" title="Share this code">Share</a>
+		{{end}}
 	</div>
 </div>
 {{end}}