claat, render: support of an "offline" out format

The offline output creates a set of files, each per step,
to support a codelab consumption directly from an offline storage, such
as a USB thumbdrive.

claat/Makefile

@@ -38,7 +38,7 @@ $(OUTDIR)/claat-%: GOARCH=$(subst .exe,,$(word 2,$(subst -, ,$*)))
 $(OUTDIR)/claat-%: $(SRCS) VERSION
 	GOOS=$(GOOS) GOARCH=$(GOARCH) go build -o $@ $(LDFLAGS)
 
-%/tmpldata.go: %/gen-tmpldata.go %/template.html %/template.md
+%/tmpldata.go: %/gen-tmpldata.go %/template.html %/template.md %/template-offline.html
 	cd $* && go generate
 
 release: $(RELEASES)

claat/VERSION

@@ -1 +1 @@
-0.5.1
+0.6.0

claat/export.go

@@ -15,7 +15,6 @@
 package main
 
 import (
-	"bytes"
 	"encoding/json"
 	"flag"
 	"fmt"
@@ -106,23 +105,7 @@ func exportCodelab(src string) (*types.Meta, error) {
 // writeCodelab stores codelab main content in ctx.Format and its metadata
 // in JSON format on disk.
 func writeCodelab(dir string, clab *types.Codelab, ctx *types.Context) error {
-	// render main codelab content to a tmp buffer,
-	// which will also verify output format is valid,
-	// and avoid creating empty files in case this goes wrong
-	data := &render.Context{
-		Env:      ctx.Env,
-		Prefix:   ctx.Prefix,
-		GlobalGA: ctx.MainGA,
-		Meta:     &clab.Meta,
-		Steps:    clab.Steps,
-		Extra:    extraVars,
-	}
-	var buf bytes.Buffer
-	if err := render.Execute(&buf, ctx.Format, data); err != nil {
-		return err
-	}
 	// output to stdout does not include metadata
-	w := os.Stdout
 	if !isStdout(dir) {
 		// make sure codelab dir exists
 		if err := os.MkdirAll(dir, 0755); err != nil {
@@ -134,16 +117,58 @@ func writeCodelab(dir string, clab *types.Codelab, ctx *types.Context) error {
 		if err := writeMeta(f, cm); err != nil {
 			return err
 		}
-		// main content file
-		f = filepath.Join(dir, contentFile(ctx.Format))
-		var err error
-		if w, err = os.Create(f); err != nil {
+	}
+
+	// main content file(s)
+	data := &struct {
+		render.Context
+		Current *types.Step
+		StepNum int
+		Prev    bool
+		Next    bool
+	}{Context: render.Context{
+		Env:      ctx.Env,
+		Prefix:   ctx.Prefix,
+		GlobalGA: ctx.MainGA,
+		Meta:     &clab.Meta,
+		Steps:    clab.Steps,
+		Extra:    extraVars,
+	}}
+	if ctx.Format != "offline" {
+		w := os.Stdout
+		if !isStdout(dir) {
+			f, err := os.Create(filepath.Join(dir, "index."+ctx.Format))
+			if err != nil {
+				return err
+			}
+			w = f
+			defer f.Close()
+		}
+		return render.Execute(w, ctx.Format, data)
+	}
+	for i, step := range clab.Steps {
+		data.Current = step
+		data.StepNum = i + 1
+		data.Prev = i > 0
+		data.Next = i < len(clab.Steps)-1
+		w := os.Stdout
+		if !isStdout(dir) {
+			name := "index.html"
+			if i > 0 {
+				name = fmt.Sprintf("step-%d.html", i+1)
+			}
+			f, err := os.Create(filepath.Join(dir, name))
+			if err != nil {
+				return err
+			}
+			w = f
+			defer f.Close()
+		}
+		if err := render.Execute(w, ctx.Format, data); err != nil {
 			return err
 		}
-		defer w.Close()
 	}
-	_, err := w.Write(buf.Bytes())
-	return err
+	return nil
 }
 
 func slurpImages(client *http.Client, dir string, steps []*types.Step) (map[string]string, error) {

claat/main.go

@@ -44,9 +44,6 @@ const (
 	// imgDirname is where a codelab images are stored,
 	// relative to the codelab dir.
 	imgDirname = "img"
-	// contentFilename is the name of file for codelab content output,
-	// without the format extension.
-	contentFilename = "index"
 	// metaFilename is codelab metadata file.
 	metaFilename = "codelab.json"
 	// stdout is a special value for -o cli arg to identify stdout writer.
@@ -77,11 +74,6 @@ func isStdout(filename string) bool {
 	return filename == stdout
 }
 
-// contentFile returns codelab main output file given the specified format.
-func contentFile(format string) string {
-	return contentFilename + "." + format
-}
-
 // printf prints formatted string fmt with args to stderr.
 func printf(format string, args ...interface{}) {
 	log.Printf(format, args...)
@@ -153,13 +145,17 @@ Export takes one or more 'src' documents and converts them
 to the format specified with -f option.
 
 The following formats are built-in:
+
 - html (Polymer-based app)
 - md (Markdown)
+- offline (plain HTML markup for offline consumption)
+
 To use a custom format, specify a local file path to a Go template file.
 More info on Go templates: https://golang.org/pkg/text/template/.
 
 Each 'src' can be either a remote HTTP resource or a local file.
 Source formats currently supported are:
+
 - Google Doc (Codelab Format, go/codelab-guide)
 - Markdown
 

claat/render/gen-tmpldata.go

@@ -32,8 +32,9 @@ var files = map[string]struct {
 	file string
 	html bool
 }{
-	"html": {"template.html", true},
-	"md":   {"template.md", false},
+	"html":    {"template.html", true},
+	"md":      {"template.md", false},
+	"offline": {"template-offline.html", true},
 }
 
 func main() {

claat/render/template-offline.html

@@ -0,0 +1,78 @@
+<!--
+Copyright (c) 2016 Google Inc.
+
+Licensed under the Apache License, Version 2.0 (the "License"); you may not
+use this file except in compliance with the License. You may obtain a copy of
+the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+License for the specific language governing permissions and limitations under
+the License.
+-->
+
+<!doctype html>
+<html>
+<head>
+  <meta charset="utf-8">
+  <meta http-equiv="X-UA-Compatible" content="IE=edge">
+  <meta name="viewport" content="width=device-width, minimum-scale=1.0, initial-scale=1.0, user-scalable=yes">
+  <title>{{.Meta.Title}}</title>
+  <link rel="stylesheet" href="https://fonts.googleapis.com/css?family=Source+Code+Pro:400|Roboto:400,300,400italic,500,700|Roboto+Mono">
+  <link rel="stylesheet" href="{{.Prefix}}styles/codelab.css">
+  <style>
+    html {
+        height: 100%;
+        margin: 0;
+        padding: 0;
+    }
+  </style>
+</head>
+
+<body class="codelab-takeover">
+  <div class="codelab__toc">{{range $i, $t := .Steps}}
+    <a href="{{inc $i | stepLink}}" class="{{inc $i | tocItemClass $.StepNum}}">
+      <span class="toc-item__index">{{inc $i}}</span>
+      <span class="toc-item__title">{{$t.Title}}</span>
+    </a>{{end}}
+  </div>
+
+  <div class="codelab__step">
+
+    <div class="step__header">
+      <a href="{{dec .StepNum | stepLink}}"{{if not .Prev}} class="invis"{{end}}>
+        <svg fill="#FFFFFF" height="24" viewbox="0 0 24 24" width="24" xmlns="http://www.w3.org/2000/svg">
+          <path d="M0 0h24v24H0z" fill="none"/>
+          <path d="M20 11H7.83l5.59-5.59L12 4l-8 8 8 8 1.41-1.41L7.83 13H20v-2z"/>
+        </svg>
+      </a>
+
+      <a href="{{.Prefix}}index.html" title="Return to home page">
+        <svg fill="#FFFFFF" height="24" viewbox="0 0 24 24" width="24" xmlns="http://www.w3.org/2000/svg">
+          <path d="M10 20v-6h4v6h5v-8h3L12 3 2 12h3v8z"/>
+          <path d="M0 0h24v24H0z" fill="none"/>
+        </svg>
+      </a>
+
+      <a href="{{inc .StepNum | stepLink}}"{{if not .Next}} class="invis"{{end}}>
+        <svg fill="#FFFFFF" height="24" viewbox="0 0 24 24" width="24" xmlns="http://www.w3.org/2000/svg">
+          <path d="M0 0h24v24H0z" fill="none"/>
+          <path d="M12 4l-1.41 1.41L16.17 11H4v2h12.17l-5.58 5.59L12 20l8-8z"/>
+        </svg>
+      </a>
+
+      <h1>{{.Meta.Title}}</h1>
+    </div>
+
+    <div class="step__body">
+      <h1>{{.Meta.Title}}</h1>
+      <h2>{{.StepNum}}. {{.Current.Title}}</h2>
+      {{.Current.Content | renderLite .Env}}
+    </div>
+
+  </div><!-- codelab__toc -->
+</body>
+</html>

claat/render/template.go

@@ -15,6 +15,7 @@
 package render
 
 import (
+	"fmt"
 	htmlTemplate "html/template"
 	"io"
 	"io/ioutil"
@@ -77,6 +78,28 @@ var funcMap = map[string]interface{}{
 		i := sort.SearchStrings(tags, t)
 		return i < len(tags) && tags[i] == t
 	},
+	// lite/offline versions; multiple step files
+	"inc": func(n int) int {
+		return n + 1
+	},
+	"dec": func(n int) int {
+		return n - 1
+	},
+	"tocItemClass": func(curr, n int) string {
+		a := "toc-item"
+		if n < curr {
+			a += " toc-item--complete"
+		} else if curr == n {
+			a += " toc-item--current"
+		}
+		return a
+	},
+	"stepLink": func(n int) string {
+		if n <= 1 {
+			return "index.html"
+		}
+		return fmt.Sprintf("step-%d.html", n)
+	},
 }
 
 //go:generate go run gen-tmpldata.go