CodeIgniter form_open() action not working correctly - forms

Question

I have have a view in which there's a form that manages products (either add new product or -if an id passed- editing an existing one). If an id is passed then the form action should be eg 'admin/product/manage/5', if no id passed then it should be like this 'admin/product/manage'.
<?php echo form_open('admin/product/manage/{optional product id}', array('class' => 'ajax-form')); ?>
I have also created and this route:
$route['admin/product/manage'] = "admin/product/manage";
$route['admin/product/manage/(:num)'] = "admin/product/manage/$1";
How can I make my form action work correctly? is it possible to put inside the action the route somehow??
This is my Controller:
public function manage($id = NULL){
//fetch a single product to edit or create a new one
if (isset($id) === true) {
$data['prod'] = $this->product_model->get($id);
$data['vers'] = $this->product_version_model->get_by('product_id',$id);
} else {
$data['prod'] = $this->product_model->make_new();// this returns $product->product_name = ''; in order to be empty the input field and not throughing errors
}
$this->product_model->save_product();
$this->product_version_model->save_version();
// load the view
$this->layout->view('admin/products/manage', $data);
}
This is my view:
<?php echo form_open('admin/product/manage', array('class' => 'ajax-form')); ?>
<p>
<label for="product_name">Product *</label>
<input type="text" name="product_name" value="<?php echo set_value('product_name', $prod->product_name); ?>" />
<?php echo form_error('product_name'); ?>
</p>
<?php echo form_close() . PHP_EOL; ?>

Answer 1

You need to declare both possible routes in order of importance, so:
$route['admin/product'] = "admin/product/manage";
$route['admin/product/(:num)'] = "admin/product/manage/$1";
From the Codeigniter Docs:
Routes will run in the order they are defined. Higher routes will always take precedence over lower ones.
Edit:
According to the changes you have made to your question I can say the following:
First of all isset() returns boolean only, so you don't need the type check "=== true". isset($id) is sufficient.
In order to have your form action set to the id you need to include it either in a hidden field or in the action itself.
So for example:
$action_id = (isset($id) ? '/'.$id : ''); // Using ternary operators here
echo form_open('admin/product/manage'.$action_id, array('class' => 'ajax-form'));
and add the id to the view data in your controller:
$data['id'] = $id;
As a side note: In order to comply with SoC (Separation of Concerns) you'd prepare all data in your controller (with e.g. models all having their own task) and pass the processed data to the view instead of partially generating data in the view itself.