1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
|
package templ
import "net/http"
// ComponentHandler is a http.Handler that renders components.
type ComponentHandler struct {
Component Component
Status int
ContentType string
ErrorHandler func(r *http.Request, err error) http.Handler
StreamResponse bool
}
const componentHandlerErrorMessage = "templ: failed to render template"
func (ch *ComponentHandler) ServeHTTPBuffered(w http.ResponseWriter, r *http.Request) {
// Since the component may error, write to a buffer first.
// This prevents partial responses from being written to the client.
buf := GetBuffer()
defer ReleaseBuffer(buf)
err := ch.Component.Render(r.Context(), buf)
if err != nil {
if ch.ErrorHandler != nil {
w.Header().Set("Content-Type", ch.ContentType)
ch.ErrorHandler(r, err).ServeHTTP(w, r)
return
}
http.Error(w, componentHandlerErrorMessage, http.StatusInternalServerError)
return
}
w.Header().Set("Content-Type", ch.ContentType)
if ch.Status != 0 {
w.WriteHeader(ch.Status)
}
// Ignore write error like http.Error() does, because there is
// no way to recover at this point.
_, _ = w.Write(buf.Bytes())
}
func (ch *ComponentHandler) ServeHTTPStreamed(w http.ResponseWriter, r *http.Request) {
w.Header().Set("Content-Type", ch.ContentType)
if ch.Status != 0 {
w.WriteHeader(ch.Status)
}
if err := ch.Component.Render(r.Context(), w); err != nil {
if ch.ErrorHandler != nil {
w.Header().Set("Content-Type", ch.ContentType)
ch.ErrorHandler(r, err).ServeHTTP(w, r)
return
}
http.Error(w, componentHandlerErrorMessage, http.StatusInternalServerError)
}
}
// ServeHTTP implements the http.Handler interface.
func (ch ComponentHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
if ch.StreamResponse {
ch.ServeHTTPStreamed(w, r)
return
}
ch.ServeHTTPBuffered(w, r)
}
// Handler creates a http.Handler that renders the template.
func Handler(c Component, options ...func(*ComponentHandler)) *ComponentHandler {
ch := &ComponentHandler{
Component: c,
ContentType: "text/html; charset=utf-8",
}
for _, o := range options {
o(ch)
}
return ch
}
// WithStatus sets the HTTP status code returned by the ComponentHandler.
func WithStatus(status int) func(*ComponentHandler) {
return func(ch *ComponentHandler) {
ch.Status = status
}
}
// WithContentType sets the Content-Type header returned by the ComponentHandler.
func WithContentType(contentType string) func(*ComponentHandler) {
return func(ch *ComponentHandler) {
ch.ContentType = contentType
}
}
// WithErrorHandler sets the error handler used if rendering fails.
func WithErrorHandler(eh func(r *http.Request, err error) http.Handler) func(*ComponentHandler) {
return func(ch *ComponentHandler) {
ch.ErrorHandler = eh
}
}
// WithStreaming sets the ComponentHandler to stream the response instead of buffering it.
func WithStreaming() func(*ComponentHandler) {
return func(ch *ComponentHandler) {
ch.StreamResponse = true
}
}
|
