internal/content: refactor and export type for content handler funcs
Simplified the content handler and exported the type for use in packages
creating a content server. A content handler now fits the interface of
http.Handler making it more portable. Simplified error handling API.
Change-Id: I2a224b9358d92821af4e0b29c5d77acfb10ef55b
Reviewed-on: https://go-review.googlesource.com/c/telemetry/+/498262
TryBot-Result: Gopher Robot <gobot@golang.org>
Run-TryBot: Jamal Carvalho <jamal@golang.org>
Reviewed-by: Hyang-Ah Hana Kim <hyangah@gmail.com>
diff --git a/godev/internal/content/content.go b/godev/internal/content/content.go
index b522f26..691762f 100644
--- a/godev/internal/content/content.go
+++ b/godev/internal/content/content.go
@@ -50,15 +50,16 @@
type contentServer struct {
fsys fs.FS
fserv http.Handler
- handlers map[string]handlerFunc
+ handlers map[string]HandlerFunc
}
-type handler struct {
- path string
- fn handlerFunc
-}
+type HandlerFunc func(http.ResponseWriter, *http.Request) error
-type handlerFunc func(http.ResponseWriter, *http.Request, fs.FS) error
+func (f HandlerFunc) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+ if err := f(w, r); err != nil {
+ handleErr(w, r, err, http.StatusInternalServerError)
+ }
+}
// Server returns a handler that serves HTTP requests with the contents
// of the file system rooted at fsys. For requests to a path without an
@@ -72,10 +73,11 @@
// For example, a server can be constructed for a file system with a single
// template, “index.html“, in a directory, “content“, and a handler:
//
-// s := content.Server(os.DirFS("content"),
-// content.Handler("/", func(w http.ReponseWriter, _ *http.Request, fsys fs.FS) error {
-// return content.Template(w, fsys, "index.html", nil, http.StatusOK)
-// }))
+// fsys := os.DirFS("content")
+// s := content.Server(fsys,
+// content.Handler("/", func(w http.ReponseWriter, _ *http.Request) error {
+// return content.Template(w, fsys, "index.html", nil, http.StatusOK)
+// }))
//
// or without a handler:
//
@@ -84,7 +86,7 @@
// Both examples will render the template index.html for requests to "/".
func Server(fsys fs.FS, handlers ...*handler) http.Handler {
fserv := http.FileServer(http.FS(fsys))
- hs := make(map[string]handlerFunc)
+ hs := make(map[string]HandlerFunc)
for _, h := range handlers {
if _, ok := hs[h.path]; ok {
panic("multiple registrations for " + h.path)
@@ -94,21 +96,23 @@
return &contentServer{fsys, fserv, hs}
}
-func Handler(path string, h handlerFunc) *handler {
+type handler struct {
+ path string
+ fn HandlerFunc
+}
+
+func Handler(path string, h HandlerFunc) *handler {
return &handler{path, h}
}
func (c *contentServer) ServeHTTP(w http.ResponseWriter, r *http.Request) {
if len(r.URL.Path) > 255 {
- Error(w, r, errors.New("url too long"), http.StatusBadRequest)
+ handleErr(w, r, errors.New("url too long"), http.StatusBadRequest)
return
}
- if handler, ok := c.handlers[r.URL.Path]; ok {
- err := handler(w, r, c.fsys)
- if err != nil {
- Error(w, r, err, http.StatusInternalServerError)
- }
+ if h, ok := c.handlers[r.URL.Path]; ok {
+ h.ServeHTTP(w, r)
return
}
@@ -120,7 +124,7 @@
filepath, info, err := stat(c.fsys, r.URL.Path)
if errors.Is(err, fs.ErrNotExist) {
- Error(w, r, errors.New("page not found"), http.StatusNotFound)
+ handleErr(w, r, errors.New(http.StatusText(http.StatusNotFound)), http.StatusNotFound)
return
}
if err == nil {
@@ -140,7 +144,7 @@
}
}
if err != nil {
- Error(w, r, err, http.StatusInternalServerError)
+ handleErr(w, r, err, http.StatusInternalServerError)
}
}
@@ -205,8 +209,30 @@
return nil
}
-// Error writes an error as an HTTP response with a status code.
-func Error(w http.ResponseWriter, req *http.Request, err error, code int) {
+// Error annotates an error with http status information.
+func Error(err error, code int) error {
+
+ return &contentError{err, code}
+}
+
+// Error status returns a content error from a status code.
+func ErrorStatus(code int) error {
+ err := errors.New(http.StatusText(code))
+ return &contentError{err, code}
+}
+
+type contentError struct {
+ err error
+ Code int
+}
+
+func (e *contentError) Error() string { return e.err.Error() }
+
+// handleErr writes an error as an HTTP response with a status code.
+func handleErr(w http.ResponseWriter, req *http.Request, err error, code int) {
+ if cerr, ok := err.(*contentError); ok {
+ code = cerr.Code
+ }
if code == http.StatusInternalServerError {
http.Error(w, http.StatusText(http.StatusInternalServerError), code)
} else {
diff --git a/godev/internal/content/content_test.go b/godev/internal/content/content_test.go
index 1d2bcc5..3f65036 100644
--- a/godev/internal/content/content_test.go
+++ b/godev/internal/content/content_test.go
@@ -19,11 +19,12 @@
)
func TestServer_ServeHTTP(t *testing.T) {
- server := Server(os.DirFS("testdata"),
- Handler("/data", handleTemplate),
- Handler("/json", handleJSON),
- Handler("/text", handleText),
- Handler("/error", handleError),
+ fsys := os.DirFS("testdata")
+ server := Server(fsys,
+ Handler("/data", handleTemplate(fsys)),
+ Handler("/json", handleJSON()),
+ Handler("/text", handleText()),
+ Handler("/error", handleError()),
)
tests := []struct {
@@ -140,19 +141,23 @@
}
}
-func handleTemplate(w http.ResponseWriter, _ *http.Request, fsys fs.FS) error {
- return Template(w, fsys, "data.html", "Data from Handler", http.StatusOK)
+func handleTemplate(fsys fs.FS) HandlerFunc {
+ return func(w http.ResponseWriter, _ *http.Request) error {
+ return Template(w, fsys, "data.html", "Data from Handler", http.StatusOK)
+ }
}
-
-func handleJSON(w http.ResponseWriter, _ *http.Request, fsys fs.FS) error {
- return JSON(w, struct{ Data string }{Data: "Data"}, http.StatusOK)
+func handleJSON() HandlerFunc {
+ return func(w http.ResponseWriter, _ *http.Request) error {
+ return JSON(w, struct{ Data string }{Data: "Data"}, http.StatusOK)
+ }
}
-
-func handleText(w http.ResponseWriter, _ *http.Request, fsys fs.FS) error {
- return Text(w, "Hello, World!", http.StatusOK)
+func handleText() HandlerFunc {
+ return func(w http.ResponseWriter, _ *http.Request) error {
+ return Text(w, "Hello, World!", http.StatusOK)
+ }
}
-
-func handleError(w http.ResponseWriter, r *http.Request, fsys fs.FS) error {
- Error(w, r, errors.New("Bad Request"), http.StatusBadRequest)
- return nil
+func handleError() HandlerFunc {
+ return func(w http.ResponseWriter, r *http.Request) error {
+ return Error(errors.New("Bad Request"), http.StatusBadRequest)
+ }
}
diff --git a/godev/internal/content/testdata/404.html.out b/godev/internal/content/testdata/404.html.out
index 3261618..e3bf314 100644
--- a/godev/internal/content/testdata/404.html.out
+++ b/godev/internal/content/testdata/404.html.out
@@ -1 +1 @@
-page not found
+Not Found
