下拉菜单打开另一个下拉菜单 - CodeIgniter

Question

I have a dropdown menu that I supplied for foreach statement for and on select I need it open up another drop down menu to specify the items

DropDown 1 - Categories (All Done)

On Click of Category

Open all the products that are associated with that Category.

Should I do a Ajax request and then in the controller select all products under that category - return the array and then supply a foreach statement to select those products?

Would appreciate also links where something like this has been done before.

Answer 1

Here is a snippet code i used to create ajax driven multiple drop down menu. Actually i have 2 methods for sake of simplicity i am posting simplest method ie one that doesn't has json manipulations.

In the view page

 <select class="form-control" name="categories" id="categories" onchange="load_products()" > 
     <option value="" selected="selected"><?php echo "Select A Category" ; ?></option> 
 </select> 

 <select class="form-control" name="products" id="products" required/></select>

JavaScript code in view page

<script> 
    function load_products() 
    { 
        categories=$('#categories').val(); 

        if($('#categories').val()!="" && $('#categories').val()!="*") { 

            $.ajax({ 
                type: "POST", 
                url: " <?php echo base_url('Home/load_products'); ?>", 
                data: "categories=" + categories, 
                success: function (msg) { 
                    if (msg) { 
                        $('#products').html(msg); 
                      //  $('#products').removeClass('hidden') 
                    } 
                    } 
            }); 
           // return false; 
        } 
        else { 
            $('#products').html(''); 
     //   $('#products').addClass('hidden') 

        } 
    } 
</script> 

Now in the controller

      function load_products() 
        { 
            $categories=$this->input->post('categories'); 

            $products=$this->Homemodel->allproducts($categories); 

            if($products!=NULL) 
            { 
                $fop="Select A Product "; 
              echo ($this->create_drop_down($fop,$products,'productname','id')); 
            } 
            else{ 
                echo "<option value=''>No Product Found</option>"; 

            } 
        } 

      function create_drop_down($options,$opts,$txt,$val) 
       { 
            $options = "<option value=''>".$options."</option>"; 

            if(!empty($opts)) 
            { 
                foreach ($opts as $row) 
                { 

                    $options.="<option value='".$row->$val."'>".$row->$txt."</option>"; 
                } 
            } 
            return $options; 
        } 

I am skipping model code. If this method doe not work for you comment below.