Add TemplateRenderer struct to ease creating renderers for `html/temp…

…late` and `text/template` packages.

echo.go

@@ -45,7 +45,6 @@ import (
 	"encoding/json"
 	"errors"
 	"fmt"
-	"io"
 	stdLog "log"
 	"net"
 	"net/http"
@@ -142,11 +141,6 @@ type JSONSerializer interface {
 	Deserialize(c Context, i interface{}) error
 }
 
-// Renderer is the interface that wraps the Render function.
-type Renderer interface {
-	Render(io.Writer, string, interface{}, Context) error
-}
-
 // Map defines a generic map of type `map[string]interface{}`.
 type Map map[string]interface{}
 

renderer.go

@@ -0,0 +1,29 @@
+package echo
+
+import "io"
+
+// Renderer is the interface that wraps the Render function.
+type Renderer interface {
+	Render(io.Writer, string, interface{}, Context) error
+}
+
+// TemplateRenderer is helper to ease creating renderers for `html/template` and `text/template` packages.
+// Example usage:
+//
+//		e.Renderer = &echo.TemplateRenderer{
+//			Template: template.Must(template.ParseGlob("templates/*.html")),
+//		}
+//
+//	  e.Renderer = &echo.TemplateRenderer{
+//			Template: template.Must(template.New("hello").Parse("Hello, {{.}}!")),
+//		}
+type TemplateRenderer struct {
+	Template interface {
+		ExecuteTemplate(wr io.Writer, name string, data any) error
+	}
+}
+
+// Render renders the template with given data.
+func (t *TemplateRenderer) Render(w io.Writer, name string, data interface{}, c Context) error {
+	return t.Template.ExecuteTemplate(w, name, data)
+}

renderer_test.go

@@ -0,0 +1,28 @@
+package echo
+
+import (
+	"github.com/stretchr/testify/assert"
+	"html/template"
+	"net/http"
+	"net/http/httptest"
+	"strings"
+	"testing"
+)
+
+func TestRenderWithTemplateRenderer(t *testing.T) {
+	e := New()
+	req := httptest.NewRequest(http.MethodPost, "/", strings.NewReader(userJSON))
+	rec := httptest.NewRecorder()
+
+	c := e.NewContext(req, rec)
+
+	e.Renderer = &TemplateRenderer{
+		Template: template.Must(template.New("hello").Parse("Hello, {{.}}!")),
+	}
+
+	err := c.Render(http.StatusOK, "hello", "Jon Snow")
+	if assert.NoError(t, err) {
+		assert.Equal(t, http.StatusOK, rec.Code)
+		assert.Equal(t, "Hello, Jon Snow!", rec.Body.String())
+	}
+}