Added attachment as option in Context.File function

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

context.go

@@ -3,15 +3,13 @@ package echo
 import (
 	"encoding/json"
 	"encoding/xml"
-	"io"
 	"net/http"
+	"path"
 
 	"fmt"
 
 	"net/url"
 
-	"os"
-
 	"golang.org/x/net/websocket"
 )
 
@@ -166,16 +164,14 @@ func (c *Context) XML(code int, i interface{}) error {
 	return xml.NewEncoder(c.response).Encode(i)
 }
 
-// File sends a file as attachment.
-func (c *Context) File(name string) error {
-	file, err := os.Open(name)
-	if err != nil {
-		return err
+// File sends a response with the content of the file. If attachment is true, the
+// client is prompted to save the file.
+func (c *Context) File(name string, attachment bool) error {
+	dir, file := path.Split(name)
+	if attachment {
+		c.response.Header().Set(ContentDisposition, "attachment; filename="+file)
 	}
-	fi, _ := file.Stat()
-	c.response.Header().Set(ContentDisposition, "attachment; filename="+fi.Name())
-	_, err = io.Copy(c.response, file)
-	return err
+	return serveFile(dir, file, c)
 }
 
 // NoContent sends a response with no body and a status code.

context_test.go

@@ -141,12 +141,22 @@ func TestContext(t *testing.T) {
 	// File
 	rec = httptest.NewRecorder()
 	c = NewContext(req, NewResponse(rec), New())
-	err = c.File("test/fixture/walle.png")
+	err = c.File("test/fixture/walle.png", false)
 	if assert.NoError(t, err) {
 		assert.Equal(t, http.StatusOK, rec.Code)
 		assert.Equal(t, 219885, rec.Body.Len())
 	}
 
+	// File as attachment
+	rec = httptest.NewRecorder()
+	c = NewContext(req, NewResponse(rec), New())
+	err = c.File("test/fixture/walle.png", true)
+	if assert.NoError(t, err) {
+		assert.Equal(t, http.StatusOK, rec.Code)
+		assert.Equal(t, rec.Header().Get(ContentDisposition), "attachment; filename=walle.png")
+		assert.Equal(t, 219885, rec.Body.Len())
+	}
+
 	// NoContent
 	rec = httptest.NewRecorder()
 	c = NewContext(req, NewResponse(rec), New())

website/docs/guide.md

@@ -368,6 +368,15 @@ Context.String(code int, s string) error
 
 Sends a text/plain HTTP response with status code.
 
+### File 
+
+```go
+Context.File(name string, attachment bool) error
+```
+
+File sends a response with the content of the file. If attachment is true, the client
+is prompted to save the file.
+
 ### Static files
 
 `Echo.Static(path, root string)` serves static files. For example, code below serves