Codeigniter-如何仅在默认控制器和方法中调用辅助方法

Question

I created a helper for save user_agent in db that have a method saveVisit();

visit_helper :

  function saveVisit($visitable_type='',$visitable_id='')
  {
    $CI =& get_instance();
    $CI->load->library('user_agent');
    $ip = $CI->input->ip_address();

    $userId = $CI->session->userdata('userId');
    if (!isset($userId)) {
      $userId = 0;
    }
    if ($CI->agent->is_mobile()) {
      $mobile=$CI->agent->mobile();
    }else {
      $mobile=0;
    }
    $data = array(
      'ip'=>$ip,
      'visitable_id'=>$visitable_id,
      'visitable_type'=>$visitable_type,
      'user_id'=>$userId,
      'created_at'=>dbtime(),
      'browser'=>$CI->agent->browser(),
      'version'=>$CI->agent->version(),
      'platform'=>$CI->agent->platform(),
      'mobile'=>$mobile,
      'referral'=>$CI->agent->referrer(),
    );
    $CI->db->insert('visits',$data);
  }

When i call a method like saveVisit(); that created in my helper , everything is ok and it called where i writed !

But when i call this method from $route['default_controller'] = 'display/home'; this method will called from all of methods in all of my controllers !!!

I want to call this method only home page not all controllers/methods !

This issue is for only my $route['default_controller'] = 'display/home';

code of my controller :

class Display extends CI_Controller {
    public function __construct()
  {
        parent::__construct();
  }
    public function home()
    {
        // some codes here 
        saveVisit('home');
    }
}

I want saveVisit(); called only in home page not others

EDITED :

I created a new function in helper to test and called in default controller , function is called once BUT runned twice !

test method code in helper :

 function test()
  {
      $CI =& get_instance();

      if ($CI->session->userdata('visit')!=null) {
        $plus = $CI->session->userdata('visit');
        $CI->session->set_userdata('visit',$plus+1);
        echo $CI->session->userdata('visit');
      }else {
        $CI->session->set_userdata('visit',1);
      }

And when i call test(); inside default Controller result for every page refresh is (Other controllers was Normal) :

2
4
6
8
10
12
14
.
.
. 

Why this happen ?

EDIT 3 :

When i call a helper function inside default controller it will run twice and run once from other controllers ! the problem is i didn't call function in other controllers

Answer 1

Instead of calling test() function to each of the function in Display class, call it inside __construct()

<?php

class Display extends CI_Controller {

    public function __construct(){
        parent::__construct();
        test();
    }

    public function home(){
        // some codes here 
        saveVisit('home');

    }
}