Q:

Get event when replacing node with the same value?

is it possible to get an event in a Listener when I replace value of a node with the same value? seams like if firebase notice that the value is the same no event accures..:s

A:

The Firebase Database synchronizes state between clients. If a write operation doesn't change the state, there is nothing to synchronize to the other listening clients.
In simple code:
ref.setValue(1);
ref.setValue(1); // won't trigger listeners
ref.setValue(2); // will trigger active listeners
ref.setValue(2); // won't trigger listeners

It sounds like you want to instead pass messages between clients. This is totally feasible, but means that you should model your data differently. Instead of storing the value in your database, store the fact that the client wrote a value.
In simple code:
ref.push(1);
ref.push(1);
ref.push(2);
ref.push(2);

In this last sample each write will trigger listeners on ref, since each write is new.
This is a common pattern: instead of storing the final state, you're storing the state changes. It essentially similar the mechanism behind oplogs in databases and many other systems.

