Setting up using layout templates

galley.go

@@ -1,23 +1,16 @@
 package main
 
 import (
-	"html/template"
 	"log"
 	"net/http"
 	"os"
-	"regexp"
 )
 
-// cache templates on initialization
-var templates = template.Must(template.ParseFiles("tmpl/edit.html", "tmpl/view.html"))
-
-var validPath = regexp.MustCompile("^/(edit|save|view)/([a-zA-Z0-9]+)$")
-
 func main() {
 	http.Handle("/static/", http.StripPrefix("/static/", http.FileServer(http.Dir("static"))))
-	http.HandleFunc("/view/", makeHandler(viewHandler))
-	http.HandleFunc("/edit/", makeHandler(editHandler))
-	http.HandleFunc("/save/", makeHandler(saveHandler))
+	http.HandleFunc("/view/", MakeHandler(ViewHandler))
+	http.HandleFunc("/edit/", MakeHandler(EditHandler))
+	http.HandleFunc("/save/", MakeHandler(SaveHandler))
 	log.Fatal(http.ListenAndServe(":8080", nil))
 }
 
@@ -39,49 +32,3 @@ func loadPage(title string) (*Page, error) {
 	}
 	return &Page{Title: title, Body: body}, nil
 }
-
-func viewHandler(w http.ResponseWriter, r *http.Request, title string) {
-	p, err := loadPage(title)
-	if err != nil {
-		http.Redirect(w, r, "/edit/"+title, http.StatusFound)
-		return
-	}
-	renderTemplate(w, "view", p)
-}
-
-func editHandler(w http.ResponseWriter, r *http.Request, title string) {
-	p, err := loadPage(title)
-	if err != nil {
-		p = &Page{Title: title}
-	}
-	renderTemplate(w, "edit", p)
-}
-
-func saveHandler(w http.ResponseWriter, r *http.Request, title string) {
-	body := r.FormValue("body")
-	p := &Page{Title: title, Body: []byte(body)}
-	err := p.save()
-	if err != nil {
-		http.Error(w, err.Error(), http.StatusInternalServerError)
-	}
-	http.Redirect(w, r, "/view/"+title, http.StatusFound)
-}
-
-func renderTemplate(w http.ResponseWriter, tmpl string, p *Page) {
-	err := templates.ExecuteTemplate(w, tmpl + ".html", p)
-	if err != nil {
-		http.Error(w, err.Error(), http.StatusInternalServerError)
-	}
-}
-
-// function that takes in and modifies a function
-func makeHandler(fn func(http.ResponseWriter, *http.Request, string)) http.HandlerFunc {
-	return func(w http.ResponseWriter, r *http.Request) {
-		m := validPath.FindStringSubmatch(r.URL.Path)
-		if m == nil {
-			http.NotFound(w, r)
-			return
-		}
-		fn(w, r, m[2])
-	}
-}

galley_http.go

@@ -0,0 +1,47 @@
+package main
+
+import (
+	"net/http"
+	"regexp"
+)
+
+var validPath = regexp.MustCompile("^/(edit|save|view)/([a-zA-Z0-9]+)$")
+
+func ViewHandler(w http.ResponseWriter, r *http.Request, title string) {
+	p, err := loadPage(title)
+	if err != nil {
+		http.Redirect(w, r, "/edit/"+title, http.StatusFound)
+		return
+	}
+	RenderTemplate(w, "view", p)
+}
+
+func EditHandler(w http.ResponseWriter, r *http.Request, title string) {
+	p, err := loadPage(title)
+	if err != nil {
+		p = &Page{Title: title}
+	}
+	RenderTemplate(w, "edit", p)
+}
+
+func SaveHandler(w http.ResponseWriter, r *http.Request, title string) {
+	body := r.FormValue("body")
+	p := &Page{Title: title, Body: []byte(body)}
+	err := p.save()
+	if err != nil {
+		http.Error(w, err.Error(), http.StatusInternalServerError)
+	}
+	http.Redirect(w, r, "/view/"+title, http.StatusFound)
+}
+
+// function that takes in and modifies a function
+func MakeHandler(fn func(http.ResponseWriter, *http.Request, string)) http.HandlerFunc {
+	return func(w http.ResponseWriter, r *http.Request) {
+		m := validPath.FindStringSubmatch(r.URL.Path)
+		if m == nil {
+			http.NotFound(w, r)
+			return
+		}
+		fn(w, r, m[2])
+	}
+}

galley_templates.go

@@ -0,0 +1,52 @@
+package main
+
+import (
+	"fmt"
+	"html/template"
+	"log"
+	"net/http"
+	"path/filepath"
+)
+
+// cache templates on initialization
+var templates map[string]*template.Template
+
+// Load templates on program initialisation
+func init() {
+	if templates == nil {
+		templates = make(map[string]*template.Template)
+	}
+
+	templatesDir := "tmpl/"
+
+	layouts, err := filepath.Glob(templatesDir + "layouts/*.html")
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	includes, err := filepath.Glob(templatesDir + "includes/*.html")
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	// Generate our templates map from our layouts/ and includes/ directories
+	for _, layout := range layouts {
+		files := append(includes, layout)
+		templates[filepath.Base(layout)] = template.Must(template.ParseFiles(files...))
+	}
+}
+
+// renderTemplate is a wrapper around template.ExecuteTemplate.
+func RenderTemplate(w http.ResponseWriter, name string, p *Page) {
+	// Ensure the template exists in the map.
+	tmpl, ok := templates[name+".html"]
+	if !ok {
+		http.Error(w, fmt.Errorf("The template %s does not exist.", name).Error(), http.StatusInternalServerError)
+	}
+
+	w.Header().Set("Content-Type", "text/html; charset=utf-8")
+	err := tmpl.ExecuteTemplate(w, "base", p)
+	if err != nil {
+		http.Error(w, err.Error(), http.StatusInternalServerError)
+	}
+}

tmpl/edit.html

@@ -1,6 +0,0 @@
-<h1>Editing {{.Title}}</h1>
-
-<form action="/save/{{.Title}}" method="POST">
-<div><textarea name="body" rows="20" cols="80">{{printf "%s" .Body}}</textarea></div>
-<div><input type="submit" value="Save"></div>
-</form>

tmpl/includes/base.html

@@ -0,0 +1,16 @@
+{{ define "base" }}
+<!DOCTYPE html>
+<html lang="en">
+
+<head>
+    <meta charset="UTF-8">
+    {{ template "head" . }}
+    <title>{{ template "title" . }}</title>
+</head>
+
+<body>
+    {{ template "content" . }}
+</body>
+
+</html>
+{{ end }}

tmpl/layouts/edit.html

@@ -0,0 +1,16 @@
+{{ define "head" }}
+    <link href="/static/css/main.css" rel="stylesheet" />
+{{ end }}
+
+{{ define "title" }}
+    {{.Title}}
+{{ end }}
+
+{{ define "content" }}
+    <h1>Editing {{.Title}}</h1>
+
+    <form action="/save/{{.Title}}" method="POST">
+    <div><textarea name="body" rows="20" cols="80">{{printf "%s" .Body}}</textarea></div>
+    <div><input type="submit" value="Save"></div>
+    </form>
+{{ end }}

tmpl/layouts/view.html

@@ -1,14 +1,13 @@
-<!doctype html>
-<html lang="en">
-
-<head>
+{{ define "head" }}
     <link href="/static/css/main.css" rel="stylesheet" />
-</head>
+{{ end }}
 
-<body>
+{{ define "title" }}
+    {{.Title}}
+{{ end }}
+
+{{ define "content" }}
     <h1>{{.Title}}</h1>
     <p>[<a href="/edit/{{.Title}}">edit</a>]</p>
     <div>{{printf "%s" .Body}}<div>
-</body>
-
-</html>
+{{ end }}