If you need an action when the button is pressed, more preciesley at the one moment it is pressed, then an 'edge detector' is needed.
The logic is build as follows: current state of gpio input is compared with the last state. Use a variabale to preserve last state. When current state is '0' an dlast state is '1', then a button press has happened.
set lastValue = '1' forever if lastValue == '1' and if gpio23 sensorvalue == 0 send broadcast 'button pressed' end if set lastValue = gpio23 sensorvalue
This effort is needed because gpioserver does not provide edge detection or event based inputs.