Merge pull request #55 from sschepens/master

Add AnswerCallbackQuery

bot.go

@@ -592,3 +592,31 @@ func (b *Bot) AnswerInlineQuery(query *Query, response *QueryResponse) error {
 
 	return nil
 }
+
+// AnswerCallbackQuery sends a response for a given callback query. A callback can
+// only be responded to once, subsequent attempts to respond to the same callback
+// will result in an error.
+func (b *Bot) AnswerCallbackQuery(callback *Callback, response *CallbackResponse) error {
+	response.CallbackID = callback.ID
+
+	responseJSON, err := sendCommand("answerCallbackQuery", b.Token, response)
+	if err != nil {
+		return err
+	}
+
+	var responseRecieved struct {
+		Ok          bool
+		Description string
+	}
+
+	err = json.Unmarshal(responseJSON, &responseRecieved)
+	if err != nil {
+		return err
+	}
+
+	if !responseRecieved.Ok {
+		return fmt.Errorf("telebot: %s", responseRecieved.Description)
+	}
+
+	return nil
+}

types.go

@@ -177,6 +177,21 @@ type Callback struct {
 	Data      string `json:"data"`
 }
 
+// CallbackResponse builds a response to an Callback query.
+// See also: https://core.telegram.org/bots/api#answerCallbackQuery
+type CallbackResponse struct {
+	// The ID of the callback to which this is a response.
+	// It is not necessary to specify this field manually.
+	CallbackID string `json:"callback_query_id"`
+
+	// Text of the notification. If not specified, nothing will be shown to the user.
+	Text string `json:"text,omitempty"`
+
+	// (Optional) If true, an alert will be shown by the client instead
+	// of a notification at the top of the chat screen. Defaults to false.
+	ShowAlert bool `json:"show_alert,omitempty"`
+}
+
 // Venue object represents a venue location with name, address and optional foursquare id.
 type Venue struct {
 	Location      Location `json:"location"`