feat(renderer): add XHTML5 support (#618)

This adds support for XHTML5 output, tests, and the `-b` (or `--bakend`)
flag which can now be used like `-b [html,html5,xhtml,xhtml5]`.

Tests are enclosed, and we leverage as much
as we can from the HTML5 backend.

Also, added test cases to cover both HTML and XHTML5 backends,
as well as invalid backends.

Fixes #601

cmd/libasciidoc/root_cmd.go

@@ -23,6 +23,7 @@ func NewRootCmd() *cobra.Command {
 	var outputName string
 	var logLevel string
 	var css string
+	var backend string
 	var attributes []string
 
 	rootCmd := &cobra.Command{
@@ -55,8 +56,9 @@ func NewRootCmd() *cobra.Command {
 						configuration.WithFilename(sourcePath),
 						configuration.WithAttributes(attrs),
 						configuration.WithCSS(css),
+						configuration.WithBackEnd(backend),
 						configuration.WithHeaderFooter(!noHeaderFooter))
-					_, err := libasciidoc.ConvertFileToHTML(out, config)
+					_, err := libasciidoc.ConvertFile(out, config)
 					if err != nil {
 						return err
 					}
@@ -72,6 +74,7 @@ func NewRootCmd() *cobra.Command {
 	flags.StringVar(&logLevel, "log", "warning", "log level to set [debug|info|warning|error|fatal|panic]")
 	flags.StringVar(&css, "css", "", "the path to the CSS file to link to the document")
 	flags.StringArrayVarP(&attributes, "attribute", "a", []string{}, "a document attribute to set in the form of name, name!, or name=value pair")
+	flags.StringVarP(&backend, "backend", "b", "html5", "backend to format the file")
 	return rootCmd
 }
 

libasciidoc.go

@@ -3,6 +3,8 @@
 package libasciidoc
 
 import (
+	"fmt"
+	"github.com/bytesparadise/libasciidoc/pkg/renderer/sgml/xhtml5"
 	"io"
 	"os"
 	"time"
@@ -27,10 +29,10 @@ var (
 	BuildTime = ""
 )
 
-// ConvertFileToHTML converts the content of the given filename into an HTML document.
+// ConvertFile converts the content of the given filename into an output document.
 // The conversion result is written in the given writer `output`, whereas the document metadata (title, etc.) (or an error if a problem occurred) is returned
-// as the result of the function call.
-func ConvertFileToHTML(output io.Writer, config configuration.Configuration) (types.Metadata, error) {
+// as the result of the function call.  The output format is determined by config.Backend (HTML5 default).
+func ConvertFile(output io.Writer, config configuration.Configuration) (types.Metadata, error) {
 	file, err := os.Open(config.Filename)
 	if err != nil {
 		return types.Metadata{}, errors.Wrapf(err, "error opening %s", config.Filename)
@@ -42,16 +44,27 @@ func ConvertFileToHTML(output io.Writer, config configuration.Configuration) (ty
 		return types.Metadata{}, errors.Wrapf(err, "error opening %s", config.Filename)
 	}
 	config.LastUpdated = stat.ModTime()
-	return ConvertToHTML(file, output, config)
+	return Convert(file, output, config)
 }
 
-// ConvertToHTML converts the content of the given reader `r` into a full HTML document, written in the given writer `output`.
-// Returns an error if a problem occurred
-func ConvertToHTML(r io.Reader, output io.Writer, config configuration.Configuration) (types.Metadata, error) {
+// Convert converts the content of the given reader `r` into a full output document, written in the given writer `output`.
+// Returns an error if a problem occurred. The default will be HTML5, but depends on the config.BackEnd value.
+func Convert(r io.Reader, output io.Writer, config configuration.Configuration) (types.Metadata, error) {
+
+	var render func(*renderer.Context, types.Document, io.Writer) (types.Metadata, error)
+	switch config.BackEnd {
+	case "html", "html5", "":
+		render = html5.Render
+	case "xhtml", "xhtml5":
+		render = xhtml5.Render
+	default:
+		return types.Metadata{}, fmt.Errorf("backend '%s' not supported", config.BackEnd)
+	}
+
 	start := time.Now()
 	defer func() {
 		duration := time.Since(start)
-		log.Debugf("rendered the HTML output in %v", duration)
+		log.Debugf("rendered the output in %v", duration)
 	}()
 	log.Debugf("parsing the asciidoc source...")
 	doc, err := parser.ParseDocument(r, config) //, parser.Debug(true))
@@ -70,10 +83,11 @@ func ConvertToHTML(r io.Reader, output io.Writer, config configuration.Configura
 	}
 	// render
 	ctx := renderer.NewContext(doc, config)
-	metadata, err := html5.Render(ctx, doc, output)
+	metadata, err := render(ctx, doc, output)
 	if err != nil {
 		return types.Metadata{}, err
 	}
 	log.Debugf("Done processing document")
 	return metadata, nil
+
 }

libasciidoc_test.go

@@ -470,6 +470,89 @@ Last updated {{.LastUpdated}}
 					configuration.WithCSS("path/to/style.css"),
 					configuration.WithHeaderFooter(true))).To(MatchHTMLTemplate(expectedContent, lastUpdated))
 			})
+
+			It("should render html", func() {
+				source := `= Story
+
+Our story begins.`
+				expectedContent := `<!DOCTYPE html>
+<html lang="en">
+<head>
+<meta charset="UTF-8">
+<meta http-equiv="X-UA-Compatible" content="IE=edge">
+<meta name="viewport" content="width=device-width, initial-scale=1.0">
+<meta name="generator" content="libasciidoc">
+<title>Story</title>
+</head>
+<body class="article">
+<div id="header">
+<h1>Story</h1>
+</div>
+<div id="content">
+<div class="paragraph">
+<p>Our story begins.</p>
+</div>
+</div>
+<div id="footer">
+<div id="footer-text">
+Last updated {{.LastUpdated}}
+</div>
+</div>
+</body>
+</html>`
+				Expect(Render(source,
+					configuration.WithBackEnd("html5"),
+					configuration.WithLastUpdated(lastUpdated),
+					configuration.WithHeaderFooter(true))).To(MatchHTMLTemplate(expectedContent, lastUpdated))
+			})
+
+			It("should render xhtml", func() {
+				source := `= Story
+
+Our story begins.`
+				expectedContent := `<!DOCTYPE html>
+<html xmlns="http://www.w3.org/1999/xhtml" lang="en">
+<head>
+<meta charset="UTF-8"/>
+<meta http-equiv="X-UA-Compatible" content="IE=edge"/>
+<meta name="viewport" content="width=device-width, initial-scale=1.0"/>
+<meta name="generator" content="libasciidoc"/>
+<title>Story</title>
+</head>
+<body class="article">
+<div id="header">
+<h1>Story</h1>
+</div>
+<div id="content">
+<div class="paragraph">
+<p>Our story begins.</p>
+</div>
+</div>
+<div id="footer">
+<div id="footer-text">
+Last updated {{.LastUpdated}}
+</div>
+</div>
+</body>
+</html>`
+				Expect(Render(source,
+					configuration.WithBackEnd("xhtml5"),
+					configuration.WithLastUpdated(lastUpdated),
+					configuration.WithHeaderFooter(true))).To(MatchHTMLTemplate(expectedContent, lastUpdated))
+			})
+
+			It("should fail given bogus backend", func() {
+				source := `= Story
+
+Our story begins.`
+				doc, err := Render(source,
+					configuration.WithBackEnd("wordperfect"),
+					configuration.WithLastUpdated(lastUpdated),
+					configuration.WithHeaderFooter(true))
+				Expect(doc).To(BeEmpty())
+				Expect(err).To(MatchError("backend 'wordperfect' not supported"))
+			})
+
 		})
 
 	})

pkg/configuration/configuration.go

@@ -24,6 +24,7 @@ type Configuration struct {
 	LastUpdated         time.Time
 	IncludeHeaderFooter bool
 	CSS                 string
+	BackEnd             string
 	macros              map[string]MacroTemplate
 }
 
@@ -90,6 +91,13 @@ func WithCSS(href string) Setting {
 	}
 }
 
+// WithBackEnd sets the backend format, valid values are "html", "html5", "xhtml", "xhtml5", and "" (defaults to html5)
+func WithBackEnd(backend string) Setting {
+	return func(config *Configuration) {
+		config.BackEnd = backend
+	}
+}
+
 // WithFilename function to set the `filename` setting in the config
 func WithFilename(filename string) Setting {
 	return func(config *Configuration) {

pkg/renderer/sgml/paragraph.go

@@ -275,10 +275,13 @@ func (r *sgmlRenderer) renderLines(ctx *renderer.Context, lines [][]interface{},
 			// log.Debugf("rendered line is not the last one in the slice")
 			var err error
 			if linesRenderer.hardBreaks {
-				_, err = buf.WriteString("<br>\n") // TODO: linebreak template
-			} else {
-				_, err = buf.WriteString("\n")
+				if br, err := r.renderLineBreak(); err != nil {
+					return nil, errors.Wrap(err, "unable to render hardbreak")
+				} else if _, err = buf.Write(br); err != nil {
+					return nil, errors.Wrap(err, "unable to write hardbreak")
+				}
 			}
+			_, err = buf.WriteString("\n")
 			if err != nil {
 				return nil, errors.Wrap(err, "unable to render lines")
 			}

pkg/renderer/sgml/xhtml5/article.adoc

@@ -0,0 +1,91 @@
+= AsciiDoc Article Title
+Firstname Lastname <author@asciidoctor.org>
+1.0, July 29, 2014, Asciidoctor 1.5 article template
+:toc:
+:icons: font
+:quick-uri: https://asciidoctor.org/docs/asciidoc-syntax-quick-reference/
+
+Content entered directly below the header but before the first section heading is called the preamble.
+
+== First level heading
+
+This is a paragraph with a *bold* word and an _italicized_ word.
+
+.Image caption
+image::image-file-name.png[I am the image alt text.]
+
+This is another paragraph.footnote:[I am footnote text and will be displayed at the bottom of the article.]
+
+=== Second level heading
+
+.Unordered list title
+* list item 1
+** nested list item
+*** nested nested list item 1
+*** nested nested list item 2
+* list item 2
+
+This is a paragraph.
+
+.Example block title
+====
+Content in an example block is subject to normal substitutions.
+====
+
+.Sidebar title
+****
+Sidebars contain aside text and are subject to normal substitutions.
+****
+
+==== Third level heading
+
+[#id-for-listing-block]
+.Listing block title
+----
+Content in a listing block is subject to verbatim substitutions.
+Listing block content is commonly used to preserve code input.
+----
+
+===== Fourth level heading
+
+.Table title
+|===
+|Column heading 1 |Column heading 2
+
+|Column 1, row 1
+|Column 2, row 1
+
+|Column 1, row 2
+|Column 2, row 2
+|===
+
+====== Fifth level heading
+
+[quote, firstname lastname, movie title]
+____
+I am a block quote or a prose excerpt.
+I am subject to normal substitutions.
+____
+
+[verse, firstname lastname, poem title and more]
+____
+I am a verse block.
+  Indents and endlines are preserved in verse blocks.
+____
+
+== First level heading
+
+TIP: There are five admonition labels: Tip, Note, Important, Caution and Warning.
+
+// I am a comment and won't be rendered.
+
+. ordered list item
+.. nested ordered list item
+. ordered list item
+
+The text at the end of this sentence is cross referenced to <<_third_level_heading,the third level heading>>
+
+== First level heading
+
+This is a link to the https://asciidoctor.org/docs/user-manual/[Asciidoctor User Manual].
+This is an attribute reference {quick-uri}[which links this text to the Asciidoctor Quick Reference Guide].

pkg/renderer/sgml/xhtml5/article_adoc_test.go

@@ -0,0 +1,32 @@
+package xhtml5_test
+
+import (
+	"bufio"
+	"bytes"
+	"github.com/bytesparadise/libasciidoc/pkg/renderer/sgml/xhtml5"
+	"os"
+
+	"github.com/bytesparadise/libasciidoc/pkg/configuration"
+	"github.com/bytesparadise/libasciidoc/pkg/parser"
+	"github.com/bytesparadise/libasciidoc/pkg/renderer"
+	"github.com/davecgh/go-spew/spew"
+	. "github.com/onsi/ginkgo" //nolint golint
+	. "github.com/onsi/gomega" //nolint golint
+)
+
+var _ = Describe("article.adoc", func() {
+
+	It("should render without failure", func() {
+		f, err := os.Open("article.adoc")
+		Expect(err).ToNot(HaveOccurred())
+		reader := bufio.NewReader(f)
+		config := configuration.NewConfiguration()
+		doc, err := parser.ParseDocument(reader, config)
+		Expect(err).ToNot(HaveOccurred())
+		GinkgoT().Logf("actual document: `%s`", spew.Sdump(doc))
+		buff := &bytes.Buffer{}
+		ctx := renderer.NewContext(doc, config)
+		_, err = xhtml5.Render(ctx, doc, buff)
+		Expect(err).ToNot(HaveOccurred())
+	})
+})

pkg/renderer/sgml/xhtml5/blank_line.go

@@ -0,0 +1,6 @@
+package xhtml5
+
+const (
+	lineBreakTmpl = "<br/>"
+	blankLineTmpl = "\n\n"
+)