如何在Codeigniter中将set_select与Ajax结合使用

Question

I need use set_select but the options of the select2 are called from controller with ajax. How can I do?

My controller:

public function getCategoryByLocation()
{
    $location_id = $this->input->post('location_id');
    $locationscats = $this->Categories_model->getCategorylocal($location_id);
    if(count($locationscats) > 0)
    {
        $select = '';
        $select .= '<option value="">'.$this->lang->line('text_none').'</option>';
        foreach ($locationscats as $locationscat) {
            $select .='<option value="'.$locationscat->category_id.'">'.$locationscat->name.'</option>';
        }
        echo json_encode($select);
    }else{
        $select = '';
        $select .= '<option value="">'.$this->lang->line('text_none').'</option>';
        echo json_encode($select);
    }

}

My Model:

public function getCategorylocal($location_id)
{
    $query = $this->db->get_where('categories', array('location_id' => $location_id));
    return $query->result();
}

My View:

<select name="parent_id" id="category" class="form-control">
                            <option value=""><?php echo lang('text_none'); ?></option>                          
                        </select>

And the Ajax call..

$(document).ready(function() {
$('#input-location').on('change', function() {
    var location_id = this.value;
    $.ajax({
        url:"<?php echo site_url("/categories/getCategoryByLocation"); ?>",
        type: "POST",
        data: {'location_id' : location_id},
        dataType: 'json',
        success: function(data){
            $('#category').html(data);
        },
        error: function(){
            alert('Error occur...!!');
        }
    });
});
$("#input-location").trigger('change');});

Is possible used set_select from the controller?... I'm using set_select in the views but no in controller...

Answer 1

I don't see where you using set_select in your view but since you're returning an HTML fragment of options, you can just return the view without doing json encoding.

$this->load->view('view_that_builds_options', $this->locationscats);

Or build the $select var and echo that...

public function getCategoryByLocation() {

 $this->load->helper('form');

 $location_id = $this->input->post('location_id');
 $locationscats = $this->Categories_model->getCategorylocal($location_id);

  $select .= '<option value="">'.$this->lang->line('text_none').'</option>';

 if(count($locationscats) > 0) {

    foreach ($locationscats as $locationscat) {
       $select .='<option value="'.$locationscat->category_id.'">'

       // assume your select is named 'category' by the id='category'.
       $select .= set_select('category', $NoIdeaWhatValueYouAreCheckingForGoesHere);

       $select .= $locationscat->name.'</option>';
    }

}

echo $select;

}