server rendering markdown with live reload on file update working

main.go

@@ -0,0 +1,134 @@
+package main
+
+import (
+	"html/template"
+	"log"
+	"net/http"
+	"strings"
+	"time"
+
+	"github.com/fsnotify/fsnotify"
+	"github.com/gorilla/mux"
+	"github.com/gorilla/websocket"
+)
+
+var (
+	upgrader = websocket.Upgrader{
+		ReadBufferSize:  1024,
+		WriteBufferSize: 1024,
+	}
+)
+
+type PageModel struct {
+	Title   string
+	Content template.HTML
+	LastMod time.Time
+}
+
+func main() {
+	router := mux.NewRouter()
+	router.HandleFunc("/", getDir).Methods("GET")
+	router.HandleFunc("/{path}", getPage).Methods("GET")
+	router.HandleFunc("/ws/{path}", serveWs)
+
+	log.Println("md-live-server web server running")
+	log.Print("port: 8080")
+	log.Fatal(http.ListenAndServe(":8080", router))
+}
+
+func getDir(w http.ResponseWriter, r *http.Request) {
+	elements := readDir("./")
+	var content string
+	content = `<ul>`
+	for _, elem := range elements {
+		content += `
+		<li><a href="` + elem + `">` + elem + `</a></li>
+		`
+	}
+	content += `</ul>`
+	var page PageModel
+	page.Title = "dir"
+	page.Content = template.HTML(content)
+
+	tmplPage := template.Must(template.New("t").Parse(dirTemplate))
+	tmplPage.Execute(w, page)
+}
+
+func getPage(w http.ResponseWriter, r *http.Request) {
+	vars := mux.Vars(r)
+	path := vars["path"]
+	path = strings.Replace(path, "%", "/", -1)
+	log.Println(path)
+
+	if strings.Split(path, ".")[1] != "md" {
+		http.ServeFile(w, r, path)
+	}
+
+	content, err := fileToHTML(path)
+	check(err)
+
+	var page PageModel
+	page.Title = path
+	page.Content = template.HTML(content)
+
+	tmplPage := template.Must(template.New("t").Parse(htmlTemplate))
+	tmplPage.Execute(w, page)
+}
+
+func serveWs(w http.ResponseWriter, r *http.Request) {
+	vars := mux.Vars(r)
+	path := vars["path"]
+	path = strings.Replace(path, "%", "/", -1)
+	log.Println("websocket", path)
+
+	ws, err := upgrader.Upgrade(w, r, nil)
+	if err != nil {
+		if _, ok := err.(websocket.HandshakeError); !ok {
+			log.Println(err)
+		}
+		return
+	}
+
+	// watch file
+	watcher, err := fsnotify.NewWatcher()
+	if err != nil {
+		log.Fatal(err)
+	}
+	defer watcher.Close()
+
+	done := make(chan bool)
+	go func() {
+		for {
+			select {
+			case event, ok := <-watcher.Events:
+				if !ok {
+					return
+				}
+				log.Println("event:", event)
+				if event.Op&fsnotify.Write == fsnotify.Write {
+					log.Println("modified file:", event.Name)
+					writer(ws, path)
+				}
+			case err, ok := <-watcher.Errors:
+				if !ok {
+					return
+				}
+				log.Println("error:", err)
+			}
+		}
+	}()
+
+	err = watcher.Add(path)
+	if err != nil {
+		log.Fatal(err)
+	}
+	<-done
+}
+
+func writer(ws *websocket.Conn, path string) {
+	content, err := fileToHTML(path)
+	check(err)
+	if err := ws.WriteMessage(websocket.TextMessage, []byte(content)); err != nil {
+		return
+	}
+}