Getting value of a field in a nesting relation - cakephp

Question

I have two tables with a relation. The find method works very well without problem, i get all the fields that i want between both tables. The delete method work fine also.
But i want to add a validation before delete the record, verifiying the relation with the secondary table, if the relation exists can't delete the record.
My Tables:
invoices: id, company_id, number, invoice_date
invoice_numbers: id, company_id, number
companies: id, name
My Models:
Invoice:
class Invoice extends AppModel
{
public $belongsTo = array(
'Company',
'InvoiceNumber' => array(
'className' => 'InvoiceNumber',
'foreignKey' => false,
'conditions' => array(
'InvoiceNumber.company_id = Invoice.company_id',
'InvoiceNumber.number = Invoice.number',
),
'type' => 'left',
'fields' => array(
'FacturaNumero.id',
),
)
);
}
InvoiceNumber:
class InvoiceNumber extends AppModel
{
public $hasOne = array(
'Invoice' => array(
'className' => 'Invoice',
'foreignKey' => false,
'conditions' => array(
'Invoice.company_id = InvoiceNumber.company_id',
'Invoice.number = InvoiceNumber.number',
),
'type' => 'left',
'fields' => array(
'Invoice.invoice_date',
),
)
);
}
My Controller (delete Method):
public function delete($id)
{
$this->InvoiceNumber->id = $id;
if (!$this->InvoiceNumber->exists()) {
throw new NotFoundException('Invalid Record.');
}
/**
* I want to add a validation here if field invoide_date is not null, by example
* but this dont work, because get the first value in the invoice table.
*/
if (!empty($this->InvoiceNumber->Invoice->field('invoice_date')) {
throw new NotFoundException('I Cant Delete this record.');
} else {
$this->InvoiceNumber->delete();
}
}

Answer 1

The misunderstanding here is that when you write
$this->InvoiceNumber->Invoice
you are just accesing a generic Invoice Model Object and not the Invoice of that specific InvoiceNumber
I think that you just need to change your code in
$InvoiceNumber = $this->InvoiceNumber->read();
if (!empty($InvoiceNumber['Invoice'])) {
// ...
}
but maybe this is not the best way: I think that a cleaner approach could be to do the validation in the InvoiceNumber beforeDelete() method
PS: sorry for the typos. Now should be correct