You can return $html[‘abc’] and add $html as parameter in each function and to the filter.
Exemple for the function:
function second_callback($html){
$html['def']= 'uvw';
return $html['def'];
}
You can return $html[‘abc’] and add $html as parameter in each function and to the filter.
Exemple for the function:
function second_callback($html){
$html['def']= 'uvw';
return $html['def'];
}