Dynamic get data in select box codeigniter - php

Question

I have two select boxes, if I select an option, it will give me results according to the options and then the results will display in the 2nd select box. How can I do this?
I think, I have to do a onchange function but I don't know how can I get data from controller in JavaScript .
class StockInController extends MY_Controller {
function index(){
$data['main_content'] = 'stockInView';
$this->load->model('supplierModel');
$query = $this->supplierModel->getAllSuppliers();
if ($query){
$data['records1'] = $query;
}
$this->load->model('categoryModel');
$query = $this->categoryModel->getAllCategories();
if ($query){
$data['records2'] = $query;
}
$this->load->model('itemsModel');
$query = $this->itemsModel->getAllItems();
if ($query){
$data['records3'] = $query;
}
$this->load->view('dashboardTemplate/template',$data);
}
function addStockIn(){
//getting parameters from view
$data = array(
'item_name' => $this->input->post('item_name'),
'cat_id' => $this->input->post('cat_id')
);
//$is_ajax = $this->input->post('ajax'); //or use this line
//$this->input->is_ajax_request();
$result = array();
$this->load->model('stockInModel');
$query = $this->stockInModel->addStocktoDB($data);
if ($query){ //&& any other condition
$result['res'] = 1;//process successful - replace 1 with any message
} else {
$result['res'] = 0;//process failed - replace 0 with any message
}
echo json_encode($result);//at the end of the function.
}
}
Here is the View:
<div class="control-group">
<label for="selsear" class="control-label">Select a Category</label>
<div class="controls">
<select name="select1" id="seslsear" class='cho'>
<option id = "y" value="0">--Select--</option>
<?php foreach($records2 as $r) { ?>
<option value="<?=$r->cat_id?>"><?=$r->cat_name?></option>
<?php } ?>
</select>
</div>
</div>
<div class="control-group">
<label for="selsear" class="control-label">Select an item</label>
<div class="controls">
<select name="select1" id="selsear" class='cho'>
<option id = "y" value="0">--Select--</option>
<?php foreach($records3 as $r) { ?>
<option value="<?=$r->item_id?>"><?=$r->item_name?></option>
<?php } ?>
</select>
</div>
</div>

Answer 1

You will have to write a function on-change of select box & feed data in success of ajax
$('#selsear').change(function() {
var form_data = {
item_name: $('#item_name').val(),
cat_id: $('#selsear').val()
};
$.ajax({
url:'controller_name/function_name',
data:form_data,
datatype:'application/json',
success:function(data){
$.each(data,function(i){
htmlString="<option value='"+data[i]['item_id']+"'>'"+data[i]['item_name']+"'</option>"
});
$("#selsear").html(htmlString);
}
});
The controller function name is the name of function which retrieves data from controller.
I hope this will help you!