Revision: Tue, 16 Aug 2022 19:49:12 GMT

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 $user) {
    print_r($user);
}

Manual Iteration

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

Since Cycle ORM works with entity state using dirty state approach it is 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']
];

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

By default, iterator object requires prepared data collection (cast to proper types) and won't cast them automatically. If you pass a raw data collection (without typecasting) you have to set typecast argument to true.

$iterator = \Cycle\ORM\Iterator::createWithOrm($orm, 'user', $rawData, typecast: true);

Also, it is possible to create an Iterator with the required services, instead of an ORM object:

$iterator = \Cycle\ORM\Iterator::createWithServices($heap, $schema, $entityFactory, $role, $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, $value): \Generator
{
    foreach($select->load('external')->fetchData() as $item) {
        if ($line['external']['value'] == $item) {
            yield $item;
        }
    }
}

// ...

foreach (ORM\Iterator::createWithOrm($orm, User::class, filterByExternal($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.

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