Implemented support to return arbitrary content types

AUTHORS.md

@@ -10,3 +10,4 @@ A huge thanks to all of our contributors:
 - Karan Misra 
 - strandmon 
 - yuyabe 
+- Simon Eisenmann

core.go

@@ -60,7 +60,7 @@ type PatchSupported interface {
 // You can instantiate multiple APIs on separate ports. Each API
 // will manage its own set of resources.
 type API struct {
-	mux     *http.ServeMux
+	mux            *http.ServeMux
 	muxInitialized bool
 }
 
@@ -113,7 +113,26 @@ func (api *API) requestHandler(resource interface{}) http.HandlerFunc {
 
 		code, data, header := handler(request.Form, request.Header)
 
-		content, err := json.MarshalIndent(data, "", "  ")
+		var content []byte
+		var err error
+
+		switch data.(type) {
+		case string:
+			content = []byte(data.(string))
+		case []byte:
+			content = data.([]byte)
+		default:
+			// Encode JSON.
+			content, err = json.MarshalIndent(data, "", "  ")
+			if err != nil {
+				if header == nil {
+					header = http.Header{"Content-Type": {"application/json"}}
+				} else if header.Get("Content-Type") == "" {
+					header.Set("Content-Type", "application/json")
+				}
+			}
+		}
+
 		if err != nil {
 			rw.WriteHeader(http.StatusInternalServerError)
 			return

core_test.go

@@ -1,6 +1,7 @@
 package sleepy
 
 import (
+	"fmt"
 	"io/ioutil"
 	"net/http"
 	"net/url"
@@ -15,6 +16,11 @@ func (item Item) Get(values url.Values, headers http.Header) (int, interface{},
 	return 200, data, nil
 }
 
+func (item Item) Post(values url.Values, headers http.Header) (int, interface{}, http.Header) {
+	data := fmt.Sprintf("You sent: %s", values.Get("hello"))
+	return 200, data, http.Header{"Content-Type": {"text/plain"}}
+}
+
 func TestBasicGet(t *testing.T) {
 
 	item := new(Item)
@@ -31,3 +37,24 @@ func TestBasicGet(t *testing.T) {
 		t.Error("Not equal.")
 	}
 }
+
+func TestBasicPostWithTextPlainResponse(t *testing.T) {
+
+	item := new(Item)
+
+	var api = NewAPI()
+	api.AddResource(item, "/items", "/bar", "/baz")
+	go api.Start(3000)
+	resp, err := http.PostForm("http://localhost:3000/items", url.Values{"hello": {"sleepy"}})
+	if err != nil {
+		t.Error(err)
+	}
+	if resp.Header.Get("Content-Type") != "text/plain" {
+		t.Error("Content-Type wrong.")
+	}
+	body, _ := ioutil.ReadAll(resp.Body)
+	if string(body) != "You sent: sleepy" {
+		t.Error("Not equal.")
+	}
+
+}