README

Create registries that are filled on-demand instead of wasting memory when they are never accessed.

Example

Extending

Extend AbstractRegistry for each type of registry you want to keep a set of values for.

class ItemsRegistry extends AbstractRegistry
{
    public function getName() : string
    {
        return 'items';
    }
}

class EntitiesRegistry extends AbstractRegistry
{
    protected $defaultValues = [1, 2, 3]; // Optional.

    public function getName() : string
    {
        return 'entities';
    }
}

Or if you only want strings in the registry, you can extend AbstractStringRegistry. When a non-string value is added to such a registry, InvalidValue is thrown.

class ItemsRegistry extends AbstractStringRegistry
{
    public function getName() : string
    {
        return 'items';
    }
}

Or if you want a simple container and have no use for multiple unique registries, create a new SimpleRegistry object.

$registry = new SimpleRegistry(-1, -2, -3); // Optionally add values upon instantiation.

Usage

You can either use new to create a new object for your registry or obtain a singleton via get().

$itemsRegistry = ItemsRegistry::get();
$entitiesRegistry = EntitiesRegistry::get(4, 5, 6); // Optionally add values upon FIRST get() call.

Apart from those initially-present values, you can create and register a dynamic populator. A dynamic populator adds values to the registry the first time that the registry has been queried via has() or if the registry has been forcibly populated with populate().

class ItemsPopulator implements DynamicPopulatorInterface
{
    public function populate(AbstractRegistry $registry) : void
    {
        $registry->addValues('a', 'b', 'c');
    }
}

Of course, rather than dynamically populating with hard-coded values, you would instead populate the registry through some other means, such as from a database or via an external API. After registering the populator, once has() is called, the registry will be automatically populated and will return true if the value exists.

$itemsRegistry->has('a'); // false
$itemsRegistry->register(new ItemsPopulator());
$itemsRegistry->has('a'); // true

Be warned that attempting to add multiple of the same value will result in InvalidValue being thrown. To avoid this consequence and instead cause it to fail silently, override the failSilently method.

class ItemsRegistry extends AbstractStringRegistry
{
    public function getName() : string
    {
        return 'items';
    }
    
    public function failSilently(): bool
    {
        return true;
    }
}