Adds error formatting

2015-08-12 19:23:53 +02:00
parent e71418fa92
commit 9a123c9281
3 changed files with 59 additions and 19 deletions
--- a/error_formatter.go
+++ b/error_formatter.go
@@ -0,0 +1,42 @@
+package narco
+
+import (
+	"fmt"
+	"net/http"
+
+	"golang.org/x/net/context"
+)
+
+type narcoKey int
+
+const errorFormatterKey narcoKey = 1
+
+type ErrorFomatter func(ctx context.Context, rw http.ResponseWriter, message interface{}, status int)
+
+func Error(ctx context.Context, rw http.ResponseWriter, message interface{}, status int) {
+	fmter, ok := ctx.Value(errorFormatterKey).(ErrorFomatter)
+	if ok == false {
+		//default to http formatter
+		http.Error(rw, fmt.Sprintf("%s", message), status)
+		return
+	}
+	fmter(ctx, rw, message, status)
+}
+
+var narcoDefaultFormatter ErrorFomatter
+
+func TextErrorFormatter(ctx context.Context, rw http.ResponseWriter, message interface{}, status int) {
+	rw.Header()["Content-Type"] = []string{"text/plain; charset=utf-8"}
+	rw.WriteHeader(status)
+	fmt.Fprintf(rw, "%s", message)
+}
+
+func BasicHTMLErrorFormatter(ctx context.Context, rw http.ResponseWriter, message interface{}, status int) {
+	rw.Header()["Content-Type"] = []string{"text/html; charset=utf-8"}
+	rw.WriteHeader(status)
+	fmt.Fprintf(rw, `<!doctype html><html><body><h1>Error %d</h1>%s</body></html>`, status, message)
+}
+
+func WithErrorFormatter(ctx context.Context, fmter ErrorFomatter) context.Context {
+	return context.WithValue(ctx, errorFormatterKey, fmter)
+}