CodeIgniter application 3 bug: pagination does not render properly for search results?

I am working on a online newspaper/blogging application with CodeIgniter 3.1.8 and Bootstrap 4.

I have separated the application’s back-end (dashboard) from its front-end and used Twig for the front-end views and adding theming.

I thought it was a good idea to add a search functionality for the back-end, for ease of navigating through one’s own posts (articles).

In my Posts controller (applicationcontrollersdashboardPosts.php) I have:

private function get_data(){
    $data = $this->Static_model->get_static_data();
    $data['pages'] = $this->Pages_model->get_pages();
    $data['categories'] = $this->Categories_model->get_categories();
    $data['number_of_pages'] = $this->Pages_model->count_pages();
    $data['number_of_posts'] = $this->Posts_model->get_num_rows();
    $data['number_of_categories'] = $this->Categories_model->get_num_rows();
    $data['number_of_comments'] = $this->Comments_model->get_num_rows();
    return $data;
}

public function index() {

    if (!$this->session->userdata('is_logged_in')) {
        redirect('login');
    }

    //load and configure pagination 
    $this->load->library('pagination');
    $config['base_url'] = base_url("/dashboard/posts");
    $config['query_string_segment'] = 'page';
    $config['total_rows'] = $this->Posts_model->get_num_rows();
    $config['per_page'] = 10;
    
    if (!isset($_GET[$config['query_string_segment']]) || $_GET[$config['query_string_segment']] < 1) {
        $_GET[$config['query_string_segment']] = 1;
    }
    $limit = $config['per_page'];
    $offset = ($this->input->get($config['query_string_segment']) - 1) * $limit;
    $this->pagination->initialize($config);

    $data = $this->get_data();
    $data['posts'] = $this->Posts_model->get_posts($limit, $offset);
    $data['offset'] = $offset;

    $this->load->view('dashboard/partials/header', $data);
    $this->load->view('dashboard/posts');
    $this->load->view('dashboard/partials/footer');
}

public function search() {

    if (!$this->session->userdata('is_logged_in')) {
        redirect('login');
    }

// Force validation since the form's method is GET
    $this->form_validation->set_data($this->input->get());
    $this->form_validation->set_rules('search', 'Search term', 'required|trim|min_length[3]',array('min_length' => 'The Search term must be at least 3 characters long.'));
    $this->form_validation->set_error_delimiters('<p class = "error search-error">', '</p>
        ');
    // If search fails
    if ($this->form_validation->run() === FALSE) {
        return $this->index();
    } else {
        $expression = $this->input->get('search');
        if (!$this->session->userdata('is_logged_in')) {
            redirect('login');
        }

        //load and configure pagination 
        $this->load->library('pagination');
        $config['base_url'] = base_url("/dashboard/posts");
        $config['query_string_segment'] = 'page';
        $config['total_rows'] = $this->Posts_model->get_num_rows();
        $config['per_page'] = 10;
        
        if (!isset($_GET[$config['query_string_segment']]) || $_GET[$config['query_string_segment']] < 1) {
            $_GET[$config['query_string_segment']] = 1;
        }
        $limit = $config['per_page'];
        $offset = $limit * ($this->input->get($config['query_string_segment']) - 1);
        $this->pagination->initialize($config);

        $data = $this->get_data();
        $data['expression'] = $expression;
        $data['posts'] = $this->Posts_model->search($expression, $limit, $offset);
        $data['offset'] = $offset;

        $this->load->view('dashboard/partials/header', $data);
        $this->load->view('dashboard/posts');
        $this->load->view('dashboard/partials/footer');
    }
} 

In the Posts_model model I have this for the list of posts posts:

public function get_posts($limit, $offset) {
    $this->db->select('posts.*,categories.name as post_category');
    $this->db->order_by('posts.id', 'DESC');
    $this->db->join('categories', 'posts.cat_id = categories.id', 'inner');
    $query = $this->db->get('posts', $limit, $offset);
    return $query->result();
}

The the view (posts.php):

<div class="card-body bg-white p-0">
  <div class="table-responsive">
    <table class="table table-striped table-sm mb-0">
      <thead>
        <tr>
          <th class="text-right">#</th>
          <th class="w-50">Title</th>
          <th>Publication date</th>
          <th class="text-right pr-2">Actions</th>
        </tr>
      </thead>
      <tbody>
        <?php foreach ($posts as $index => $post): ?>
        <tr data-slug="<?php echo $post->slug; ?>">
          <td class="text-right"><?php $count = $index + 1; echo $count + $offset; ?></td>
          <td><?php echo $post->title; ?></td>
          <td><?php echo nice_date($post->created_at, 'D, M d, Y'); ?></td>
          <td class="text-right">
            <div class="btn-group btn-group-sm" role="group">
              <a href="<?php echo base_url('posts/post/') . $post->slug; ?>" class="btn btn-success"><i class="fa fa-eye"></i> View</a>
              <?php if(($this->session->userdata('is_logged_in') && $this->session->userdata('user_id') == $post->author_id) || $this->session->userdata('user_is_admin')) : ?>
              <a href="<?php echo base_url('dashboard/posts/edit/') . $post->slug; ?>" class="btn btn-success"><i class="fa fa-pencil-square-o"></i> Edit</a>
              <a href="#" data-slug="<?php echo $post->slug ?>" class="delete-post ajax-btn btn btn-success"><i class="fa fa-trash"></i> Delete</a>
              <?php else: ?>
              <a href="#" class="btn btn-success disabled"><i class="fa fa-pencil-square-o"></i> Edit</a>
              <a href="#" class="btn btn-success disabled"><i class="fa fa-trash"></i> Delete</a>
              <?php endif; ?>
            </div>
          </td>
        </tr>
        <?php endforeach ?>
      </tbody>
    </table>
  </div>
  <div class="card-footer bg-white py-1">
    <?php $this->load->view("dashboard/partials/pagination");?>
  </div>
</div>

While all the posts are paginated well, strangely, the search results are not paginated well: when for instance I do a search that returns 11 results, that should be displayed on two pages, the pagination shows all the pages instead of two.

I have not been able to figure out why.

Where is my mistake?

Answer

While all the posts are paginated well, strangely, the search results are not paginated well: when for instance I do a search that returns 11 results, that should be displayed on two pages, the pagination shows all the pages instead of two.

Because you use all rows count in total_rows config: $config['total_rows'] = $this->Posts_model->get_num_rows(); In the search function you need to use the count of search result: Number of rows from this result WITHOUT!!! $limit, and $offset:

public function search() {

    if (!$this->session->userdata('is_logged_in')) {
        redirect('login');
    }

    // Force validation since the form's method is GET
    $this->form_validation->set_data($this->input->get());
    $this->form_validation->set_rules('search', 'Search term', 'required|trim|min_length[3]',array('min_length' => 'The Search term must be at least 3 characters long.'));
    $this->form_validation->set_error_delimiters('<p class = "error search-error">', '</p>
        ');
    // If search fails
    if ($this->form_validation->run() === FALSE) {
        return $this->index();
    } else {
        $expression = $this->input->get('search');
        if (!$this->session->userdata('is_logged_in')) {
            redirect('login');
        }

        //load and configure pagination 
        $this->load->library('pagination');
        $config['base_url'] = base_url("/dashboard/posts");
        $config['query_string_segment'] = 'page';
        // Only one line changed below
        $config['total_rows'] = $this->Posts_model->search_count($expression);
        $config['per_page'] = 10;
        
        if (!isset($_GET[$config['query_string_segment']]) || $_GET[$config['query_string_segment']] < 1) {
            $_GET[$config['query_string_segment']] = 1;
        }
        $limit = $config['per_page'];
        $offset = $limit * ($this->input->get($config['query_string_segment']) - 1);
        $this->pagination->initialize($config);

        $data = $this->get_data();
        $data['expression'] = $expression;
        $data['posts'] = $this->Posts_model->search($expression, $limit, $offset);
        $data['offset'] = $offset;

        $this->load->view('dashboard/partials/header', $data);
        $this->load->view('dashboard/posts');
        $this->load->view('dashboard/partials/footer');
    }
}