Entity Iterator

In order to initiate a set of entities and the tree of their relations Cycle ORM utilizes the Cycle\ORM\Iterator class, which works in generator mode.

#Select Results

By default, the Iterator object is returned from the getIterator method of the Cycle\ORM\Select class.

$select = $orm->getRepository('user')->select();

foreach ($select as $u) {
    print_r($u);
}

#Manual Iteration

Is it possible to provide input data to iterator manually, using any custom data source or raw SQL query? The data must be provided in a tree for.

Since Cycle works with entity state using dirty state approach is it possible to load results partially (if default entity values are null and does not trigger updates).

$data = [
    ['id' => 1, 'name' => 'Antony'],
    ['id' => 2, 'name' => 'John']
];

$iterator = new \Cycle\ORM\Iterator($orm, 'user', $data);

#Pre-Filtering

In some cases, you might want to filter selection results using external data sets (for example relations pointing to the external database). Since filtering such results is not possible on the database level (using joins), you might want to filter results internally, inside your PHP application.

In order to avoid additional memory consumption for objects, you can filter your results in generator mode prior to model instantiation. To do that using the Cycle\ORM\Select method fetchData:

use Cycle\ORM;

function filterByExternal(ORM\Select $select, $value)
{
    foreach($select->load('external')->fetchData() as $item) {
        if ($line['external']['value'] == $item) {
            yield $item;
        }
    }
}

// ...

foreach (new ORM\Iterator($orm, User::class, filterByExternal($select, $value)) as $user) {
    print_r($user);
}

You can combine this approach with the where option of load method to create complex cross-database queries.