Add NATS notifier (#2795)

vendor/github.com/nats-io/nats/encoders/builtin/json_enc.go

@@ -0,0 +1,45 @@
+// Copyright 2012-2015 Apcera Inc. All rights reserved.
+
+package builtin
+
+import (
+	"encoding/json"
+	"strings"
+)
+
+// JsonEncoder is a JSON Encoder implementation for EncodedConn.
+// This encoder will use the builtin encoding/json to Marshal
+// and Unmarshal most types, including structs.
+type JsonEncoder struct {
+	// Empty
+}
+
+// Encode
+func (je *JsonEncoder) Encode(subject string, v interface{}) ([]byte, error) {
+	b, err := json.Marshal(v)
+	if err != nil {
+		return nil, err
+	}
+	return b, nil
+}
+
+// Decode
+func (je *JsonEncoder) Decode(subject string, data []byte, vPtr interface{}) (err error) {
+	switch arg := vPtr.(type) {
+	case *string:
+		// If they want a string and it is a JSON string, strip quotes
+		// This allows someone to send a struct but receive as a plain string
+		// This cast should be efficient for Go 1.3 and beyond.
+		str := string(data)
+		if strings.HasPrefix(str, `"`) && strings.HasSuffix(str, `"`) {
+			*arg = str[1 : len(str)-1]
+		} else {
+			*arg = str
+		}
+	case *[]byte:
+		*arg = data
+	default:
+		err = json.Unmarshal(data, arg)
+	}
+	return
+}