Merge pull request #109 from bep/markdowncustom

genmarkdown: add optional frontmatter- and linkadjustment-funcs

md_docs.go

@@ -47,6 +47,10 @@ func (s byName) Swap(i, j int)      { s[i], s[j] = s[j], s[i] }
 func (s byName) Less(i, j int) bool { return s[i].Name() < s[j].Name() }
 
 func GenMarkdown(cmd *Command, out *bytes.Buffer) {
+	GenMarkdownCustom(cmd, out, func(s string) string { return s })
+}
+
+func GenMarkdownCustom(cmd *Command, out *bytes.Buffer, linkHandler func(string) string) {
 	name := cmd.CommandPath()
 
 	short := cmd.Short
@@ -78,7 +82,7 @@ func GenMarkdown(cmd *Command, out *bytes.Buffer) {
 			pname := parent.CommandPath()
 			link := pname + ".md"
 			link = strings.Replace(link, " ", "_", -1)
-			fmt.Fprintf(out, "* [%s](%s)\t - %s\n", pname, link, parent.Short)
+			fmt.Fprintf(out, "* [%s](%s)\t - %s\n", pname, linkHandler(link), parent.Short)
 		}
 
 		children := cmd.Commands()
@@ -91,7 +95,7 @@ func GenMarkdown(cmd *Command, out *bytes.Buffer) {
 			cname := name + " " + child.Name()
 			link := cname + ".md"
 			link = strings.Replace(link, " ", "_", -1)
-			fmt.Fprintf(out, "* [%s](%s)\t - %s\n", cname, link, child.Short)
+			fmt.Fprintf(out, "* [%s](%s)\t - %s\n", cname, linkHandler(link), child.Short)
 		}
 		fmt.Fprintf(out, "\n")
 	}
@@ -100,13 +104,17 @@ func GenMarkdown(cmd *Command, out *bytes.Buffer) {
 }
 
 func GenMarkdownTree(cmd *Command, dir string) {
-	for _, c := range cmd.Commands() {
-		GenMarkdownTree(c, dir)
+	noOp := func(s string) string { return s }
+	GenMarkdownTreeCustom(cmd, dir, noOp, noOp)
 }
 
+func GenMarkdownTreeCustom(cmd *Command, dir string, filePrepender func(string) string, linkHandler func(string) string) {
+	for _, c := range cmd.Commands() {
+		GenMarkdownTreeCustom(c, dir, filePrepender, linkHandler)
+	}
 	out := new(bytes.Buffer)
 
-	GenMarkdown(cmd, out)
+	GenMarkdownCustom(cmd, out, linkHandler)
 
 	filename := cmd.CommandPath()
 	filename = dir + strings.Replace(filename, " ", "_", -1) + ".md"
@@ -116,6 +124,11 @@ func GenMarkdownTree(cmd *Command, dir string) {
 		os.Exit(1)
 	}
 	defer outFile.Close()
+	_, err = outFile.WriteString(filePrepender(filename))
+	if err != nil {
+		fmt.Println(err)
+		os.Exit(1)
+	}
 	_, err = outFile.Write(out.Bytes())
 	if err != nil {
 		fmt.Println(err)

md_docs.md

@@ -25,7 +25,7 @@ This will generate a whole series of files, one for each command in the tree, in
 
 ## Generate markdown docs for a single command
 
-You may wish to have more control over the output, or only generate for a single command, instead of the entire command tree. If this is the case you may prefer to `GenMarkdown()` instead of `GenMarkdownTree`
+You may wish to have more control over the output, or only generate for a single command, instead of the entire command tree. If this is the case you may prefer to `GenMarkdown` instead of `GenMarkdownTree`
 
 ```go
 	out := new(bytes.Buffer)
@@ -33,3 +33,49 @@ You may wish to have more control over the output, or only generate for a single
 ```
 
 This will write the markdown doc for ONLY "cmd" into the out, buffer.
+
+## Customize the output
+
+Both `GenMarkdown` and `GenMarkdownTree` has alternate versions with callbacks to get some control of the output:
+
+```go
+func GenMarkdownTreeCustom(cmd *Command, dir string, filePrepender func(string) string, linkHandler func(string) string) {
+    //...
+}
+```
+
+```go
+func GenMarkdownCustom(cmd *Command, out *bytes.Buffer, linkHandler func(string) string) {
+    //...
+}
+```
+
+The `filePrepender` will prepend the return value given the full filepath to the rendered Markdown file. A common use case is to add front matter to use the generated documentation with [Hugo](http://gohugo.io/):
+
+```go
+const fmTemplate = `---
+date: %s
+title: "%s"
+slug: %s
+url: %s
+---
+`
+
+filePrepender := func(filename string) string {
+	now := time.Now().Format(time.RFC3339)
+	name := filepath.Base(filename)
+	base := strings.TrimSuffix(name, path.Ext(name))
+	url := "/commands/" + strings.ToLower(base) + "/"
+	return fmt.Sprintf(fmTemplate, now, strings.Replace(base, "_", " ", -1), base, url)
+}
+```
+
+The `linkHandler` can be used to customize the rendered internal links to the commands, given a filename:
+
+```go
+linkHandler := func(name string) string {
+	base := strings.TrimSuffix(name, path.Ext(name))
+	return "/commands/" + strings.ToLower(base) + "/"
+}
+```
+