配置文件中的Codeigniter分页

Question

According to the CI official documentation it's possible to set preferences in a config file, but I can't get this to work.

I think I have narrowed the issue down to line 3 of my pagination.php file - the error message I receive is;

Message: Undefined property: CI_Loader::$db

Message: Call to a member function get() on null

Whenever I change this line of code from;

$config['total_rows'] = $this->db->get('item')->num_rows();

to

$config['total_rows'] = 200;

Everything works as expected. Am I failing to load something or call the database?

My code is:

Controller

public function index() {
    $this->load->library('pagination');
    $data = array(
        'items'     => $this->items_model->itemList(),
        'title'     => 'Library Items'
        );
    $this->load->view('item_list', $data);
}

Model

public function itemList() {
    $this->db->select('item_id, item_title');
    $this->db->from('item');
    $this->db->limit(5, $this->uri->segment(3));
    return $this->db->get()->result();
}

View

<?php echo $this->pagination->create_links() ?>

pagination.php

defined('BASEPATH') OR exit('No direct script access allowed');
$config['base_url'] = '/ci/items/index';
$config['total_rows'] = $this->db->get('item')->num_rows();// when I change this to `$config['total_rows'] = 200` it works
$config['per_page'] = 5;
$config['num_links'] = 5;
$config['full_tag_open'] = '<div><ul class="pagination">';
$config['full_tag_close'] = '</ul></div><!--pagination-->';
$config['first_link'] = '&laquo; First';
$config['first_tag_open'] = '<li class="prev page">';
$config['first_tag_close'] = '</li>';
$config['last_link'] = 'Last &raquo;';
$config['last_tag_open'] = '<li class="next page">';
$config['last_tag_close'] = '</li>';
$config['next_link'] = 'Next &rarr;';
$config['next_tag_open'] = '<li class="next page">';
$config['next_tag_close'] = '</li>';
$config['prev_link'] = '&larr; Previous';
$config['prev_tag_open'] = '<li class="prev page">';
$config['prev_tag_close'] = '</li>';
$config['cur_tag_open'] = '<li class="active"><a href="">';
$config['cur_tag_close'] = '</a></li>';
$config['num_tag_open'] = '<li class="page">';
$config['num_tag_close'] = '</li>';
$config['anchor_class'] = 'follow_link';

Thanks

Answer 1

If you keep changing the question it makes previous answers look a bit strange. However you cannot load the db or use a db call in your config file. If you have to run a database query to get a value you are no longer using a config setting, but assigning a value to an arguement for use in a library method call.

So just set the config value to some fixed reasonable value, say 50, then in your controller override the setting using something like:

// load config file
$this->config->load('pagination', TRUE);

// access pagination settings
$settings = $this->config->item('pagination');

// change whatever you need to
$settings['total_rows'] = $this->db->get('item')->num_rows();

// use the settings to initialize the library
$this->pagination->initialize($settings);

There might be an easier way but as far as I know there are no other setters in the pagination library.