Move all http stuff into the http package

http/handler.go

@@ -107,7 +107,7 @@ func (this *Handler) serveDocument (
 	}
 
 	// set up HTTP response recorder
-	recorder := step.HTTPResponseRecorder { }
+	recorder := HTTPResponseRecorder { }
 	resetRecorder := func () {
 		recorder.Reset()
 		recorder.Head = res.Header().Clone()
@@ -122,7 +122,7 @@ func (this *Handler) serveDocument (
 	}
 
 	// execute document
-	data := step.HTTPData { }
+	data := HTTPData { }
 	data.Res.Header      = recorder.Header()
 	data.Res.WriteHeader = recorder.WriteHeader
 	data.Res.Reset       = resetRecorder

http/http.go

@@ -0,0 +1,66 @@
+package http
+
+import "io"
+import "bytes"
+import "net/http"
+
+// HTTPData represents information about an ongoing HTTP request that is made
+// available to templates as they are being executed.
+type HTTPData struct {
+	// Res is like an http.ResponseWriter.
+	Res struct {
+		Header      http.Header
+		WriteHeader func (statusCode int)
+		Reset       func ()
+	}
+	// Req is the HTTP request.
+	Req *http.Request
+}
+
+var _ http.ResponseWriter = new(HTTPResponseRecorder)
+
+// HTTPResponseRecorder is an http.ResponseWriter that can buffer a response to
+// be played back later.
+type HTTPResponseRecorder struct {
+	Status int
+	Head   http.Header
+	buffer bytes.Buffer
+}
+
+func (this *HTTPResponseRecorder) Header () http.Header {
+	if this.Head == nil {
+		this.Head = make(http.Header)
+	}
+	return this.Head
+}
+
+func (this *HTTPResponseRecorder) Write (buffer []byte) (int, error) {
+	return this.buffer.Write(buffer)
+}
+
+func (this *HTTPResponseRecorder) WriteHeader (statusCode int) {
+	this.Status = statusCode
+}
+// Play replays the response to the given http.ResponseWriter. This resets the
+// recorder.
+func (this *HTTPResponseRecorder) Play (res http.ResponseWriter) error {
+	defer this.Reset()
+	status := this.Status
+	if status == 0 {
+		status = http.StatusOK
+	}
+	header := res.Header()
+	for name, value := range this.Head {
+		header[name] = value
+	}
+	res.WriteHeader(status)
+	_, err := io.Copy(res, &this.buffer)
+	return err
+}
+
+// Reset resets this response recorder so it can be used again.
+func (this *HTTPResponseRecorder) Reset () {
+	this.buffer.Reset()
+	this.Head = nil
+	this.Status = http.StatusOK
+}