Question

I have a form where users can enter product id and its quantity. What I am trying to acheive is when the user submits the form, in the controller I want to check in database to see if the provided product’s quantity is available in stock, if not I want to display a validation error message in the form. If everything is okay I want to proceed to the next step.

Could you please show me how my controller should look like if I want to achieve this using Codeigniter’s default validation library?

This is my db table name: product

 product_id     category_id     product_name    product_price   product_stock
    1                1          Mango Juice         25                100
    2                2           Pepsi              10                  0

This is my View File — My Form (check this link to see the form)

<form name="form" action="base_url/my_controller/function" method="post">
   <label>One</label> 
  Product ID:<input type="text" name="productid[]" value=""> 
  Product Quantity: <input type="text" name="quantity[]" value=""> <br>

 <label>Two</label> 
 Product ID:<input type="text" name="productid[]" value=""> 
 Product Quantity: <input type="text" name="quantity[]" value=""> <br>

 <!-- there may be more inputs like above (users can create new inputs 
 as many as they want) // I have a jquery function to create new rows-->
 <input type="submit" value="submit">
 </form>

Edited Part New

function test(){

$productid = ($_POST['productid']);
$quantity = ($_POST['quantity']);


for($i = 0; $i < count($productid); $i++){
     $result=$this->enquiry($productid[$i],$quantity[$i]);

     }

/* Now I am stuck here. I don't understand how to find out if the
      products are available or not. If not I want to show the 
      error message in the form :(   */

}//function ends

function enquiry($productid,$quantity){

 $query = $this->db->query("SELECT product_stock FROM products 
                                  WHERE product_id=$productid");

if ($query->num_rows() > 0){

          foreach ($query->result() as $row){

      $product_stock=$row->product_stock;              

    }                 
 }                 
   if($product_stock>$quantity) { return FALSE;   }         

    else { return  TRUE; }              
 }//function Ends           

Answer 1

You can use a callback function. read here

$this->form_validation->set_rules('quantity[]','Quantity', 'required|callback_quantity_check');

public function quantity_check($quantity) {

     if ($this->is_available_in_stock($this->input->post('product_id[]'),$quantity)) {
        return TRUE;
     }
     else 
     {
        $this->form_validation->set_message('quantity_check', 'error');
        return FALSE;
     }
}

is_available_in_stock will check in the database the available quantity. It is recommended to check it using a model.

EDIT:

I would advise against using the form validation like mentioned above for this type of validation because you have two arrays which need to match based on their index. When using the callback function you do not know which product’s quantity you are working with.

My recommendation:

$product_ids = $this->input->post('product_id[]');
$quantities = $this->input->post('quantity[]');

//ensure the arrays are identical in size.
if (count($product_ids) == count($quantities) {

   for ($counter == 0; $counter < count($product_ids) ; $counter++) {
       $result = $this->is_available_in_stock($product_ids[counter], $quantities[counter]);
   }
}

Using this code, the is_available_in_stock function you wrote should work.

Second EDIT:

$not_available_products = array();
for($i = 0; $i < count($productid); $i++){
     $result=$this->enquiry($productid[$i],$quantity[$i]);
     if ($result == FALSE) {
          array_push($not_available_products, array($productid[$i] => $quantity[$i]));
     }
}
return $not_available_products;