Why Magento salesOrderInvoiceList is accepting store_id as a Complex filter?

Question

I must to update a code created by another programmer. It uses php - SOAP to connect Magento. I was digging to understand what he did and I found a query using Complex Filter against sales_order_invoice.list. This is the Complex Filter:

$complexFilter = array(            
      'complex_filter' => array(
        array(
               'key' => 'CREATED_AT',
               'value' => array(
                   'key' => 'from',
                   'value' => '2015-10-16 01:24:37'
               )
        ),
        array(
               'key' => 'state',
               'value' => array(
                   'key' => '=',
                   'value' => '2'
               )
        ),
        array(
               'key' => 'store_id',
               'value' => array(
                   'key' => 'in',
                   'value' => '5,6'
               )
        )
      )
);

This is the code to connect:

$cli = new SoapClient("http://MYstaging.com/api/v2_soap/?wsdl");
$username = 'myuser';
$password = 'myPass';
$session_id = $cli->login($username, $password);
#$cli->__setCookie('XDEBUG_SESSION', 'netbeans-xdebug');      
$result = $cli->salesOrderInvoiceList($session_id, $complexFilter);

As we can see, the query should retrieve some information from salesOrderInvoiceList, and it does. This is the result:

array (size=1)
  0 => 
    object(stdClass)[2]
      public 'increment_id' => string '500000001' (length=9)
      public 'created_at' => string '2015-10-16 20:07:18' (length=19)
      public 'order_currency_code' => string 'YYY' (length=3)
      public 'order_id' => string '9' (length=1)
      public 'state' => string '2' (length=1)
      public 'grand_total' => string '00.0000' (length=7)
      public 'invoice_id' => string '3' (length=1)

I do not understand this. If we check the Magendo doc to sales_order_invoice.list, there is no store_id content or field. So it should not be possible to use it as a filter. But it does exists in the sales_order_invoice.info.

Well, if I change store_id field for something that do not exist at all, lets say "BLAH_BLAH" certainly I would have nothing as result. And it is what is happening. And it makes sense. Behind the scenes maybe we have a sql 1054 (Unknow column) error.

$complexFilter = array(            
      'complex_filter' => array(
        array(
               'key' => 'CREATED_AT',
               'value' => array(
                   'key' => 'from',
                   'value' => '2015-10-16 01:24:37'
               )
        ),
        array(
               'key' => 'state',
               'value' => array(
                   'key' => '=',
                   'value' => '2'
               )
        ),
        array(
               'key' => 'BLAH_BLAH',
               'value' => array(
                   'key' => 'in',
                   'value' => '5,6'
               )
        )
      )
);

Can someone explain why salesOrderInvoiceList is accepting store_id as filter?

Answer 1

Formally, you can pass to complex filter any field from sales/order_invoice model and this field will take part in the filtering. Magento passes your complex filter to \Mage_Sales_Model_Order_Invoice_Api::items. This method inits an invoices collection:

$invoiceCollection = Mage::getResourceModel('sales/order_invoice_collection');

and then iterates over all passed filters by adding them to the set of collection filters

foreach ($filters as $field => $value) {
    $invoiceCollection->addFieldToFilter($field, $value);
}