Codeigniter Perpage Link Not Showing First In URL Pagination links - codeigniter

Question

I am making my table head links sortable and orderable how ever my per_page does not show up first
http://localhost/project-1/forum/category/1/&order=asc?per_page=1
It should show like
http://localhost/codeigniter/forum/category/1/?per_page=1&order=asc
Question when I click on the pagination links if the have been order or sorted how can I make sure that when I click on a pagination link even though has been order/sorted will still allways show ?per_page first in url.
$url = '';
if ($this->input->get('sort')) {
$url .= '&sort=' . $this->input->get('sort');
}
if ($this->input->get('order')) {
$url .= '&order=' . $this->input->get('order');
}
$config["base_url"] = base_url('forum/category') .'/'. $category_id .'/'. $url;
Controller
<?php
class Forum extends MX_Controller {
public function __construct() {
parent::__construct();
$this->load->model('catalog/forum/forum_model');
$this->load->library('pagination');
}
public function category() {
$this->document->set_title('Forums');
$category_id = $this->uri->segment(3);
if ($this->input->get('sort')) {
$sort = $this->input->get('sort');
} else {
$sort = 'message';
}
if ($this->input->get('order')) {
$order = $this->input->get('order');
} else {
$order = 'asc';
}
$url = '';
if ($this->input->get('per_page')) {
$url .= '?per_page=' . $this->input->get('per_page');
}
if ($this->input->get('sort')) {
$url .= '&sort=' . $this->input->get('sort');
}
if ($this->input->get('order')) {
$url .= '&order=' . $this->input->get('order');
}
$config["base_url"] = base_url('forum/category') .'/'. $category_id .'/'. $url;
$config["total_rows"] = $this->forum_model->total_category($category_id);
$config["per_page"] = 1;
$config['page_query_string'] = TRUE;
$config['full_tag_open'] = "<ul class='pagination'>";
$config['full_tag_close'] ="</ul>";
$config['num_tag_open'] = '<li>';
$config['num_tag_close'] = '</li>';
$config['cur_tag_open'] = "<li class='disabled'><li class='active'><a href='#'>";
$config['cur_tag_close'] = "<span class='sr-only'></span></a></li>";
$config['next_tag_open'] = "<li>";
$config['next_tagl_close'] = "</li>";
$config['prev_tag_open'] = "<li>";
$config['prev_tagl_close'] = "</li>";
$config['first_tag_open'] = "<li>";
$config['first_tagl_close'] = "</li>";
$config['last_tag_open'] = "<li>";
$config['last_tagl_close'] = "</li>";
$this->pagination->initialize($config);
$start = ($this->input->get('per_page')) ? $this->input->get('per_page') : '';
$filter_data = array(
'limit' => $config["per_page"],
'start' => $start,
'category_id' => $category_id,
'sort' => $sort,
'order' => $this->input->get('order')
);
$data['threads'] = array();
$results = $this->forum_model->get_threads_for_forum($filter_data);
foreach ($results as $result) {
$data['threads'][] = array(
'thread_id' => $result['thread_id'],
'user_id' => $result['user_id'],
'username' => $result['username'],
'subject' => $result['subject'],
'link' => site_url('thread') . '-' . $result['thread_id'],
'total' => $this->forum_model->total_threads($result['thread_id']),
'date_created' => date('d-m-Y', strtotime($result['date_created'])),
'user_link' => site_url('user') . '-' . $result['user_id']
);
}
$data['header'] = Modules::run('catalog/common/header/index');
$data['footer'] = Modules::run('catalog/common/footer/index');
$data['menu'] = Modules::run('catalog/common/menu/index');
$data['pagination'] = $this->pagination->create_links();
$data['back'] = site_url('forum');
$data['thread'] = site_url('newthread') . '?fid=' . $category_id;
$url = '';
if ($order == 'asc') {
$url .= '?order=desc';
} else {
$url .= '?order=asc';
}
$data['message'] = site_url('forum/category') .'/'. $category_id .'/'. $url;
$data['sort'] = $sort;
$data['order'] = '';
$this->load->view('default/template/forum/forum_thread_view', $data);
}
}

Answer 1

Set your default category id if url does not contain:
if ($this->uri->segment(3) == 'null') {
$category_id = 1; //set default for null
} else {
$category_id = $this->uri->segment(3);
}
Edit your config['base_url'] and add set $config['suffix'] if $_GET is not
empty.
New Pagination config:
$config["base_url"] = base_url('forum/category'); //no need custom category id
if (count($_GET) > 0)
$config['suffix']='?'.http_build_query($_GET,'',"&");//to encode requested data
$config["per_page"] = 1;
$config['page_query_string'] = TRUE;
$config['full_tag_open'] = "<ul class='pagination'>";
$config['full_tag_close'] ="</ul>";
$config['num_tag_open'] = '<li>';
$config['num_tag_close'] = '</li>';
$config['cur_tag_open'] = "<li class='disabled'><li class='active'><a href='#'>";
$config['cur_tag_close'] = "<span class='sr-only'></span></a></li>";
$config['next_tag_open'] = "<li>";
$config['next_tagl_close'] = "</li>";
$config['prev_tag_open'] = "<li>";
$config['prev_tagl_close'] = "</li>";
$config['first_tag_open'] = "<li>";
$config['first_tagl_close'] = "</li>";
$config['last_tag_open'] = "<li>";
$config['last_tagl_close'] = "</li>";

Answer 2

I don't see any:
$config[‘reuse_query_string’] = TRUE;
This will allow to use mixed type of urls. This was not possible before CI 3.0.