Renderer example

Signed-off-by: Vishal Rana <vr@labstack.com>

README.md

@@ -30,28 +30,40 @@ Echo is a fast HTTP router (zero memory allocation) + micro web framework in Go.
 package main
 
 import (
+	"io"
 	"net/http"
 
+	"html/template"
+
 	"github.com/labstack/echo"
 	mw "github.com/labstack/echo/middleware"
 	"github.com/rs/cors"
 	"github.com/thoas/stats"
 )
 
-type user struct {
+type (
-	ID   string `json:"id"`
+	// Template provides HTML template rendering
-	Name string `json:"name"`
+	Template struct {
+		templates *template.Template
+	}
+
+	user struct {
+		ID   string `json:"id"`
+		Name string `json:"name"`
+	}
+)
+
+var (
+	users map[string]user
+)
+
+// Render HTML
+func (t *Template) Render(w io.Writer, name string, data interface{}) error {
+	return t.templates.ExecuteTemplate(w, name, data)
 }
 
-var users map[string]user
+func welcome(c *echo.Context) {
-
+	c.Render("welcome", "Joe")
-func init() {
-	users = map[string]user{
-		"1": user{
-			ID:   "1",
-			Name: "Wreck-It Ralph",
-		},
-	}
 }
 
 func createUser(c *echo.Context) {
@@ -109,6 +121,16 @@ func main() {
 	e.Get("/users", getUsers)
 	e.Get("/users/:id", getUser)
 
+	//***************//
+	//   Templates   //
+	//***************//
+	t := &Template{
+		// Cached templates
+		templates: template.Must(template.ParseFiles("public/tpl/welcome.tpl")),
+	}
+	e.Renderer(t)
+	e.Get("/welcome", welcome)
+
 	//***********//
 	//   Group   //
 	//***********//
@@ -132,6 +154,15 @@ func main() {
 	// Start server
 	e.Run(":8080")
 }
+
+func init() {
+	users = map[string]user{
+		"1": user{
+			ID:   "1",
+			Name: "Wreck-It Ralph",
+		},
+	}
+}
 ```
 
 ### Benchmark

context.go

@@ -45,9 +45,14 @@ func (c *Context) Bind(v interface{}) error {
 	return ErrUnsupportedMediaType
 }
 
-func (c *Context) Render(code int, name string, data interface{}) error {
+// Render calls the registered HTML template renderer and sends a text/html
+// response.
+func (c *Context) Render(name string, data interface{}) error {
+	if c.echo.renderer == nil {
+		return ErrNoRenderer
+	}
 	c.Response.Header().Set(HeaderContentType, MIMEHTML+"; charset=utf-8")
-	c.Response.WriteHeader(code)
+	c.Response.WriteHeader(http.StatusOK)
 	return c.echo.renderer.Render(c.Response, name, data)
 }
 

context_test.go

@@ -3,11 +3,23 @@ package echo
 import (
 	"bytes"
 	"encoding/json"
+	"io"
 	"net/http"
 	"net/http/httptest"
 	"testing"
+	"text/template"
 )
 
+type (
+	Template struct {
+		templates *template.Template
+	}
+)
+
+func (t *Template) Render(w io.Writer, name string, data interface{}) error {
+	return t.templates.ExecuteTemplate(w, name, data)
+}
+
 func TestContext(t *testing.T) {
 	b, _ := json.Marshal(u1)
 	r, _ := http.NewRequest(POST, "/users/1", bytes.NewReader(b))
@@ -16,6 +28,7 @@ func TestContext(t *testing.T) {
 		Request:  r,
 		params:   make(Params, 5),
 		store:    make(store),
+		echo:     &Echo{},
 	}
 
 	//**********//
@@ -66,24 +79,38 @@ func TestContext(t *testing.T) {
 		t.Error("user name should be Joe")
 	}
 
+	// Render
+	tpl := &Template{
+		templates: template.Must(template.New("hello").Parse("{{.}}")),
+	}
+	c.echo.renderer = tpl
+	if err := c.Render("hello", "Joe"); err != nil {
+		t.Errorf("render %v", err)
+	}
+	c.echo.renderer = nil
+	if err := c.Render("hello", "Joe"); err == nil {
+		t.Error("render should error out")
+	}
+
 	// JSON
 	r.Header.Set(HeaderAccept, MIMEJSON)
+	c.Response.committed = false
 	if err := c.JSON(http.StatusOK, u1); err != nil {
-		t.Errorf("render json %v", err)
+		t.Errorf("json %v", err)
 	}
 
 	// String
 	r.Header.Set(HeaderAccept, MIMEText)
 	c.Response.committed = false
 	if err := c.String(http.StatusOK, "Hello, World!"); err != nil {
-		t.Errorf("render string %v", err)
+		t.Errorf("string %v", err)
 	}
 
 	// HTML
 	r.Header.Set(HeaderAccept, MIMEHTML)
 	c.Response.committed = false
 	if err := c.HTML(http.StatusOK, "Hello, <strong>World!</strong>"); err != nil {
-		t.Errorf("render html %v", err)
+		t.Errorf("html %v", err)
 	}
 
 	// Redirect

echo.go

@@ -65,6 +65,7 @@ var (
 
 	// Errors
 	ErrUnsupportedMediaType = errors.New("echo: unsupported media type")
+	ErrNoRenderer           = errors.New("echo: renderer not registered")
 )
 
 // New creates an Echo instance.
@@ -109,12 +110,13 @@ func (e *Echo) MaxParam(n uint8) {
 	e.maxParam = n
 }
 
-// NotFoundHandler sets a custom NotFound handler.
+// NotFoundHandler registers a custom NotFound handler.
 func (e *Echo) NotFoundHandler(h Handler) {
 	e.notFoundHandler = wrapH(h)
 }
 
-// Renderer sets an HTML Renderer.
+// Renderer registers an HTML template renderer, it is used by
+// echo.Context.Render API.
 func (e *Echo) Renderer(r Renderer) {
 	e.renderer = r
 }

example/main.go

@@ -1,28 +1,40 @@
 package main
 
 import (
+	"io"
 	"net/http"
 
+	"html/template"
+
 	"github.com/labstack/echo"
 	mw "github.com/labstack/echo/middleware"
 	"github.com/rs/cors"
 	"github.com/thoas/stats"
 )
 
-type user struct {
+type (
-	ID   string `json:"id"`
+	// Template provides HTML template rendering
-	Name string `json:"name"`
+	Template struct {
+		templates *template.Template
+	}
+
+	user struct {
+		ID   string `json:"id"`
+		Name string `json:"name"`
+	}
+)
+
+var (
+	users map[string]user
+)
+
+// Render HTML
+func (t *Template) Render(w io.Writer, name string, data interface{}) error {
+	return t.templates.ExecuteTemplate(w, name, data)
 }
 
-var users map[string]user
+func welcome(c *echo.Context) {
-
+	c.Render("welcome", "Joe")
-func init() {
-	users = map[string]user{
-		"1": user{
-			ID:   "1",
-			Name: "Wreck-It Ralph",
-		},
-	}
 }
 
 func createUser(c *echo.Context) {
@@ -80,6 +92,16 @@ func main() {
 	e.Get("/users", getUsers)
 	e.Get("/users/:id", getUser)
 
+	//***************//
+	//   Templates   //
+	//***************//
+	t := &Template{
+		// Cached templates
+		templates: template.Must(template.ParseFiles("public/tpl/welcome.tpl")),
+	}
+	e.Renderer(t)
+	e.Get("/welcome", welcome)
+
 	//***********//
 	//   Group   //
 	//***********//
@@ -103,3 +125,12 @@ func main() {
 	// Start server
 	e.Run(":8080")
 }
+
+func init() {
+	users = map[string]user{
+		"1": user{
+			ID:   "1",
+			Name: "Wreck-It Ralph",
+		},
+	}
+}