Adds ability to set a custom markdown theme by specifying the path to…

… a CSS file instead of the name of a built-in theme

README.md

@@ -55,7 +55,7 @@ Usage: `servemd [OPTIONS] [DIR]`
 | `X_ROBOTS_TAG`       | `-r --x-robots-tag`    | Sets a `X-Robots-Tag` header. Example: `"noindex, nofollow"`                                  | None          |
 | `DOCUMENT_EXTENSION` | `-e, --extension`      | Extension used for markdown files                                                             | `.md`         |
 | `DIRECTORY_INDEX`    | `-i, --index`          | Filename (without extension) to use for directory indexes                                     | `index`       |
-| `MARKDOWN_THEME`     | `-m, --markdown-theme` | Theme to use for styling markdown. Values: *clean*, *github*, *developer*                     | `clean`       |
+| `MARKDOWN_THEME`     | `-m, --markdown-theme` | Theme to use for styling markdown. Can be one of the following built-in themes: *clean*, *github*, *developer* or the path to a custom CSS file to include. | `clean`       |
 | `CODE_THEME`         | `-c, --code-theme`     | Syntax highlighting theme (powered by [highlight.js][highlightjs])                            | None          |
 
 

assets/templates/document.html

@@ -6,7 +6,7 @@
 
     {{if .MarkdownTheme}}
     <!-- Markdown Theme -->
-    <link rel="stylesheet" type="text/css" href="/assets/themes/{{.MarkdownTheme}}.css">
+    <link rel="stylesheet" type="text/css" href="{{.MarkdownTheme}}">
     {{end}}
 
     {{if .CodeTheme}}

main.go

@@ -9,7 +9,8 @@ import (
 )
 
 const (
-	Version = "0.4.0"
+	Version      = "0.4.0"
+	DefaultTheme = "clean"
 )
 
 func main() {
@@ -67,7 +68,7 @@ func main() {
 		markdownTheme = app.String(cli.StringOpt{
 			Name:   "m markdown-theme",
 			Desc:   "Theme to use for styling markdown html",
-			Value:  "clean",
+			Value:  DefaultTheme,
 			EnvVar: "MARKDOWN_THEME",
 		})
 		codeTheme = app.String(cli.StringOpt{
@@ -86,12 +87,18 @@ func main() {
 		}
 		http.HandleFunc("/assets/", headerMiddleware(staticAssetHandlerFunc))
 
+		// Setup the markdown theme (may be custom or bundled)
+		themePath, themeHandler := theme(*markdownTheme)
+		if themeHandler != nil {
+			http.HandleFunc(themePath, themeHandler)
+		}
+
 		// Markdown File Handler
 		markdownHandlerFunc := markdownHandleFunc(MarkdownHandlerOptions{
 			DocRoot:       *dir,
 			DocExtension:  *extension,
 			DirIndex:      *index,
-			MarkdownTheme: *markdownTheme,
+			MarkdownTheme: themePath,
 			CodeTheme:     *codeTheme,
 		})
 		markdownHandlerFunc = headerMiddleware(markdownHandlerFunc)

theme.go

@@ -0,0 +1,49 @@
+package main
+
+import (
+	"fmt"
+	"log"
+	"net/http"
+	"os"
+	"path/filepath"
+)
+
+func theme(value string) (string, http.HandlerFunc) {
+	// Check if the value is a path to a CSS file
+	if filepath.Ext(value) == ".css" {
+		cssPath, err := filepath.Abs(value)
+		if err != nil {
+			log.Printf("Error finding custom theme: %s: %s. Falling back to: %s.", value, err.Error(), DefaultTheme)
+			return themePath(DefaultTheme), nil
+		}
+
+		if stat, err := os.Stat(cssPath); err == nil && !stat.IsDir() {
+			// Add handler to serve content
+			handler := func(w http.ResponseWriter, r *http.Request) {
+				http.ServeFile(w, r, cssPath)
+			}
+			return themePath("custom"), handler
+		}
+
+		log.Printf("Error finding custom theme: %s. Falling back to: %s.", value, DefaultTheme)
+		return themePath(DefaultTheme), nil
+	}
+
+	// If the value is not a path, check that it is a valid bundled theme
+	localPath := themeAssetPath(value)
+	_, err := Asset(localPath)
+	if err != nil {
+		log.Printf("Invalid theme selected: %s. Falling back to: %s.", value, DefaultTheme)
+		return themePath(DefaultTheme), nil
+	}
+
+	return themePath(value), nil
+}
+
+func themePath(value string) string {
+	return fmt.Sprintf("/assets/themes/%s.css", value)
+}
+
+func themeAssetPath(value string) string {
+	return fmt.Sprintf("assets/themes/%s.css", value)
+}