add a http listener for webhooks that uses the normal updates chan

webhook.go

@@ -0,0 +1,23 @@
+package tgbotapi
+
+import (
+	"encoding/json"
+	"io/ioutil"
+	"net/http"
+)
+
+// ListenForWebhook registers a http handler for a webhook.
+// Useful for Google App Engine or other places where you cannot
+// use a normal update chan.
+func (bot *BotAPI) ListenForWebhook() {
+	bot.Updates = make(chan Update, 100)
+
+	http.HandleFunc("/"+bot.Token, func(w http.ResponseWriter, r *http.Request) {
+		bytes, _ := ioutil.ReadAll(r.Body)
+
+		var update Update
+		json.Unmarshal(bytes, &update)
+
+		bot.Updates <- update
+	})
+}