Add new TableOfContents Page variable (Markdown only)

Added TableOfContents field to hugolib.Page struct.  New function
getTableOfContents is used in convertMarkdown to set the TableOfContents
field.

Added new test file hugolib/page_toc_test.go with a simple test of the
new functionality.

Conflicts:
	hugolib/page.go

hugolib/page.go

@@ -34,22 +34,23 @@ import (
 )
 
 type Page struct {
-    Status      string
-    Images      []string
-    RawContent  []byte
-    Content     template.HTML
-    Summary     template.HTML
-    Truncated   bool
-    plain       string // TODO should be []byte
-    Params      map[string]interface{}
-    contentType string
-    Draft       bool
-    Aliases     []string
-    Tmpl        bundle.Template
-    Markup      string
-    renderable  bool
-    layout      string
-    linkTitle   string
+    Status          string
+    Images          []string
+    RawContent      []byte
+    Content         template.HTML
+    Summary         template.HTML
+    TableOfContents template.HTML
+    Truncated       bool
+    plain           string // TODO should be []byte
+    Params          map[string]interface{}
+    contentType     string
+    Draft           bool
+    Aliases         []string
+    Tmpl            bundle.Template
+    Markup          string
+    renderable      bool
+    layout          string
+    linkTitle       string
     PageMeta
     File
     Position
@@ -624,6 +625,16 @@ func (page *Page) Convert() error {
     return nil
 }
 
+func getTableOfContents(content []byte) template.HTML {
+    htmlFlags := 0
+    htmlFlags |= blackfriday.HTML_SKIP_SCRIPT
+    htmlFlags |= blackfriday.HTML_TOC
+    htmlFlags |= blackfriday.HTML_OMIT_CONTENTS
+    renderer := blackfriday.HtmlRenderer(htmlFlags, "", "")
+
+    return template.HTML(string(blackfriday.Markdown(content, renderer, 0)))
+}
+
 func (page *Page) convertMarkdown(lines io.Reader) {
     b := new(bytes.Buffer)
     b.ReadFrom(lines)
@@ -631,6 +642,7 @@ func (page *Page) convertMarkdown(lines io.Reader) {
     page.Content = template.HTML(string(blackfriday.MarkdownCommon(RemoveSummaryDivider(content))))
     summary, truncated := getSummaryString(content, "markdown")
     page.Summary = template.HTML(string(summary))
+    page.TableOfContents = getTableOfContents(RemoveSummaryDivider(content))
     page.Truncated = truncated
 }
 

hugolib/page_toc_test.go

@@ -0,0 +1,51 @@
+package hugolib
+
+import (
+	"testing"
+)
+
+func TestTableOfContents(t *testing.T) {
+	text := `
+Blah blah blah blah blah.
+
+## AA
+
+Blah blah blah blah blah.
+
+### AAA
+
+Blah blah blah blah blah.
+
+## BB
+
+Blah blah blah blah blah.
+
+### BBB
+
+Blah blah blah blah blah.
+`
+
+	markdown := RemoveSummaryDivider([]byte(text))
+	toc := string(getTableOfContents(markdown))
+
+	expected := `<nav>
+<ul>
+<li>
+<ul>
+<li><a href="#toc_0">AA</a>
+<ul>
+<li><a href="#toc_1">AAA</a></li>
+</ul></li>
+<li><a href="#toc_2">BB</a>
+<ul>
+<li><a href="#toc_3">BBB</a></li>
+</ul></li>
+</ul></li>
+</ul>
+</nav>
+`
+
+	if toc != expected {
+		t.Errorf("Expected table of contents: %s, got: %s", expected, toc)
+	}
+}