added delete after option.

channel.go

@@ -74,6 +74,13 @@ func (c Channel) SendMessage(message *SendMessage) (*Message, error) {
 		return respMessage, err
 	}
 
+	if message.DeleteAfter != 0 {
+		go func() {
+			time.Sleep(time.Second * time.Duration(message.DeleteAfter))
+			respMessage.Delete()
+		}()
+	}
+
 	return respMessage, nil
 }
 

message.go

@@ -144,5 +144,12 @@ func (m Message) Reply(mention bool, sm *SendMessage) (*Message, error) {
 		return respMessage, err
 	}
 
+	if sm.DeleteAfter != 0 {
+		go func() {
+			time.Sleep(time.Second * time.Duration(sm.DeleteAfter))
+			respMessage.Delete()
+		}()
+	}
+
 	return respMessage, nil
 }

other.go

@@ -7,6 +7,7 @@ type SendMessage struct {
 	Content     string   `json:"content,omitempty"`
 	Attachments []string `json:"attachments,omitempty"`
 	Nonce       string   `json:"nonce,omitempty"`
+	DeleteAfter uint     `json:"-"`
 	Replies     []struct {
 		Id      string `json:"id,omitempty"`
 		Mention bool   `json:"mention,omitempty"`
@@ -25,6 +26,12 @@ func (sms *SendMessage) SetContentf(format string, values ...interface{}) *SendM
 	return sms
 }
 
+// Set delete after option.
+func (sms *SendMessage) SetDeleteAfter(second uint) *SendMessage {
+	sms.DeleteAfter = second
+	return sms
+}
+
 // Add a new attachment.
 func (sms *SendMessage) AddAttachment(attachment string) *SendMessage {
 	sms.Attachments = append(sms.Attachments, attachment)