Ajax与codeigniter中的选择框

Question

i have a form with two select box. one is for the city and the other one for the area.

My requirement. When some one selects a city,The areas in the city must be captured from database and displayed in another select box.

i tried but, i have problem with my ajax. here is my code below.

view

                                    <div class="location-group">
                                    <label class="-label" for="city">
                                        Location
                                    </label>
                                    <div class="">
                                        <select id="city_select">
                                            <option value="0"> select</option>
                                            <?php foreach ($city as $cty) : ?>
                                            <option value="<?php echo $cty->city_id; ?>"><?php echo $cty->name; ?></option>
                                            <?php endforeach ?>
                                        </select>
                                    </div>
                                </div>


                                <div class="location control-group" id="area_section">
                                    <label class="control-label" for="area">
                                        Area
                                    </label>
                                    <div class="controls">
                                        <select id="area_select">
                                            <option value=""> Any</option>
                                            <?php foreach ($area as $ara) : ?>
                                            <option value="<?php echo $ara->ara_id; ?>"><?php echo $ara->name; ?></option>
                                            <?php endforeach ?>
                                        </select>
                                    </div><!-- /.controls -->
                                </div><!-- /.control-group -->

controller

function __construct() {
    parent::__construct();

  //session, url, satabase is set in auto load in the config

    $this->load->model('Home_model', 'home');
    $this->load->library('pagination');


}



function index(){
    $data['city'] =  $this->home->get_city_list();
    $data['type'] =  $this->home->get_property_type_list();
    $this->load->view('home', $data);
}


function get_area(){
    $area_id = $this->uri->segment(3);
    $areas =  $this->home->get_area_list($area_id);
    echo json_encode($areas);
}

Model

function get_area_list($id){
  $array = array('city_id' => $id, 'status' => 1);
  $this->db->select('area_id, city_id, name');
  $this->db->where($array);
  $this->db->order_by("name", "asc"); 
  $this->db->from('area'); 
  $query = $this->db->get();
  $result = $query->result();
  return $result;
}

Ajax

<script type="text/javascript">
$('#area_section').hide();


    $('#city_select').on('change', function() {
     // alert( this.value ); // or $(this).val()
      if (this.value == 0) {
        $('#area_section').hide(600);
      }else{


        //$("#area_select").html(data);
            $.ajax({
                  type:"POST",
                  dataType: 'json',
                  url:"<?php echo base_url('index.php?/home/get_area/') ?>",
                  data: {area:data},
                  success: function(data) {
                    $('select#area_select').html('');
                    $.each(data, function(item) {
                        $("<option />").val(item.area_id)
                                       .text(item.name)
                                       .appendTo($('select#area_select'));
                    });
                  }
                });


        $('#area_section').show(600); 
      };



    });
</script>

once i select a city, it must get all the areas in the city from database and display it in the area_select select box.

can any one please help me. Thanks.

Answer 1

Try to change this way.

Your ajax code

//keep rest of the code
 $.ajax({
              type:"POST",
              dataType: 'json',
              url:"<?php echo base_url('index.php?/home/get_area/') ?>",
              data: {area:$(this).val()},//send the selected area value

Also show the area_section inside ajax success function

Your controller function

function get_area()
{
   $area_id = $this->input->post('area');
   $areas =  $this->home->get_area_list($area_id);
   echo json_encode($areas);
}

Hope it will solve your problem

Update
Try using your ajax update function like this

 success: function(data) {
                $('select#area_select').html('');
                for(var i=0;i<data.length;i++)
                {
                    $("<option />").val(data[i].area_id)
                                   .text(data[i].name)
                                   .appendTo($('select#area_select'));
                }
              }

Answer 2

Simple way to do that follow the instruction on this page

---

https://itsolutionstuff.com/post/codeigniter-dynamic-dependent-dropdown-using-jquery-ajax-exampleexample.html

---

demo_state table:

CREATE TABLE `demo_state` (
  `id` int(11) NOT NULL,
  `name` varchar(155) NOT NULL,
  `created_at` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
  `updated_at` timestamp NOT NULL DEFAULT '0000-00-00 00:00:00'
) ENGINE=InnoDB DEFAULT CHARSET=latin1;

demo_cities table:

CREATE TABLE `demo_cities` (
  `id` int(11) NOT NULL,
  `state_id` int(12) NOT NULL,
  `name` varchar(155) NOT NULL,
  `created_at` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
  `updated_at` timestamp NOT NULL DEFAULT '0000-00-00 00:00:00'
) ENGINE=InnoDB DEFAULT CHARSET=latin1;

After create database and table successfully, we have to configuration of database in our Codeigniter 3 application, so open database.php file and add your database name, username and password.

application/config/database.php

<?php
defined('BASEPATH') OR exit('No direct script access allowed');


$active_group = 'default';
$query_builder = TRUE;


$db['default'] = array(
    'dsn'   => '',
    'hostname' => 'localhost',
    'username' => 'root',
    'password' => 'root',
    'database' => 'test',
    'dbdriver' => 'mysqli',
    'dbprefix' => '',
    'pconnect' => FALSE,
    'db_debug' => (ENVIRONMENT !== 'production'),
    'cache_on' => FALSE,
    'cachedir' => '',
    'char_set' => 'utf8',
    'dbcollat' => 'utf8_general_ci',
    'swap_pre' => '',
    'encrypt' => FALSE,
    'compress' => FALSE,
    'stricton' => FALSE,
    'failover' => array(),
    'save_queries' => TRUE
);

Read Also: How to make simple dependent dropdown using jquery ajax in Laravel 5? Step 3: Add Route

In this step you have to add two new routes in our route file. We will manage layout and another route for ajax, so let's put route as bellow code:

application/config/routes.php

<?php
defined('BASEPATH') OR exit('No direct script access allowed');


$route['default_controller'] = 'welcome';
$route['404_override'] = '';
$route['translate_uri_dashes'] = FALSE;


$route['myform'] = 'HomeController';
$route['myform/ajax/(:any)'] = 'HomeController/myformAjax/$1';

Step 4: Create Controller

Ok, now first we have to create one new controller HomeController with index method. so create HomeController.php file in this path application/controllers/HomeController.php and put bellow code in this file:

application/controllers/HomeController.php

<?php


class HomeController extends CI_Controller {


   /**
    * Manage __construct
    *
    * @return Response
   */
   public function __construct() { 
      parent::__construct();
      $this->load->database();
   }

   /**
    * Manage index
    *
    * @return Response
   */
   public function index() {
      $states = $this->db->get("demo_state")->result();
      $this->load->view('myform', array('states' => $states )); 
   } 

/** * Manage uploadImage * * @return Response */

   public function myformAjax($id) { 
       $result = $this->db->where("state_id",$id)->get("demo_cities")->result();
       echo json_encode($result);
   }

}

?> Step 5: Create View Files

In this step, we will create myform.php view and here we will create form with two dropdown select box. We also write ajax code here:

application/views/myform.php

<!DOCTYPE html>
<html>
<head>
    <title>Codeigniter Dependent Dropdown Example with demo</title>
    <script src="http://demo.itsolutionstuff.com/plugin/jquery.js"></script>
    <link rel="stylesheet" href="http://demo.itsolutionstuff.com/plugin/bootstrap-3.min.css">
</head>


<body>
<div class="container">
    <div class="panel panel-default">
      <div class="panel-heading">Select State and get bellow Related City</div>
      <div class="panel-body">


            <div class="form-group">
                <label for="title">Select State:</label>
                <select name="state" class="form-control" style="width:350px">
                    <option value="">--- Select State ---</option>
                    <?php
                        foreach ($states as $key => $value) {
                            echo "<option value='".$value->id."'>".$value->name."</option>";
                        }
                    ?>
                </select>
            </div>


            <div class="form-group">
                <label for="title">Select City:</label>
                <select name="city" class="form-control" style="width:350px">
                </select>
            </div>


      </div>
    </div>
</div>


<script type="text/javascript">


    $(document).ready(function() {
        $('select[name="state"]').on('change', function() {
            var stateID = $(this).val();
            if(stateID) {
                $.ajax({
                url:"<?php echo base_url('index.php/Diplome/myformAjax/') ?>"+ stateID,

                    //url: '/myform/ajax/'+stateID,
                    type: "GET",
                    dataType: "json",
                    success:function(data) {
                        $('select[name="city"]').empty();
                        $.each(data, function(key, value) {
                            $('select[name="city"]').append('<option value="'+ value.id +'">'+ value.name +'</option>');
                        });
                    }
                });
            }else{
                $('select[name="city"]').empty();
            }
        });
    });
</script>


</body>
</html>