Question

Sometimes i need data like array and sometimes i need same data as json.

Where would you do the check if is a ajax call, in controller or model or… Which one is better?

Test if is ajax call in controller

function my_controller(){
    //getdata from model
    $data=$this->my_model();
    if(THIS_IS_AJAX_CALL){
        echo json_encode($data);
    }else{
        return $data;
    }
}

function my_model(){
    //get the data from db
    return $data;
}

Pass type as argument to model:

function my_controller(){
    if(THIS_IS_AJAX_CALL){
        return $this->my_model('json');
    }else{
        return $this->my_model();
    }
}

function my_model($type=''){
    //get the data from db
    if($type='json'){
        return json_encode($data);
    }else{
        return $data;
    }
}

Answer 1

The controller. The model does not care how the data needs to be represented to the user, only the data itself.