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7.4. Reassigning Products from Deleted Categories

Now that you've met with Claudia, you know how she wants to handle potentially orphaned products. Orphaned products come about as a natural result of deleting a "container" like a category. If the category goes away, what do you do with all the items that it is "holding"? Now that you know what Claudia's expectations are, it's an easy matter of adding a bit of processing to the end of the admin/categories/delete function.

Here's a quick look at that function to refresh your memory:

function delete($id){
  $this->MCats->deleteCategory($id);
  $this->session->set_flashdata('message','Category deleted');
  redirect('admin/categories/index','refresh');
}

What you're going to need when you rewrite this function is some way to check for orphaned products. The best way to do that is to create a checkOrphans() function in the MCats model. This function accepts a category ID as its only argument and then returns an array of products that match that category_id.

function checkOrphans($id){
  $data = array();
  $this->db->select('id,name');
  $this->db->where('category_id',$id);
  $Q = $this->db->get('products');
    if ($Q->num_rows() > 0){
      foreach ($Q->result_array() as $row){
        $data[$row['id']] = $row['name'];
      }
    }
  $Q->free_result();
  return $data;
}

Now that you have this function in place, you can rewrite the delete() controller function.

function delete($id){ $this->MCats->deleteCategory($id); $orphans = $this->MCats->checkOrphans($id); if (count($orphans)){ ...