Install with composer require stratadox/entity-state
This package models the entity state at a certain point in the execution of the business logic.
The model is built in such a way that it can find differences in terms of added, altered or removed entities, when comparing itself to another point in the process.
Additionally, the package comes with a service to extract the state of the entities.
Step 1: Extract the state of the entities from the Identity Map
.
$originalState = Extract::state()->from($identityMap);
Step 2: Make some changes in the domain.
$identityMap = $identityMap->add('id-26', new Something('foo'));
$identityMap->get(User::class, '1')->changeNameTo('Chuck Norris');
$identityMap = $identityMap->remove(Foo::class, '3');
(Note: In real life you'd access the identity map through repositories instead)
Step 3: Extract the new state from the entities in the identity map.
$newState = Extract::state()->from($identityMap);
Step 4: Get the changes since the original state was captured.
$changes = $newState->changesSince($originalState);
Step 5: Profit.
assert($changes->added()[0]->class() === Something::class);
assert($changes->added()[0]->id() === 'id-26');
assert($changes->altered()[0]->class() === User::class);
assert($changes->altered()[0]->id() === '1');
assert($changes->removed()[0]->class() === Foo::class);
assert($changes->removed()[0]->id() === '3');
assert($changes->altered()[0]->properties()[0]->name() === 'userName');
assert($changes->altered()[0]->properties()[0]->value() === 'Chuck Norris');
Notice that in the above example, the user's name is stored as a string value in
the property userName
. If instead the User
class would have a Name
value
object, the assertion would look more like this:
assert($changes->altered()[0]->properties()[0]->name() === 'Name:userName.name');
If this Name
object were contained in an array, the result would look like this:
assert($changes->altered()[0]->properties()[0]->name() === 'Name:array:userName[0].name');
It may in some cases be preferable to store the string representation of an instance, rather than all its properties. To extract a string representation of the objects of a class, one can use:
$entityState = Extract::stringifying(UuidInterface::class)->from($identityMap);
Potential to-do's:
- Increase performance by hashing properties names?
- Split names into parts?
- Add methods for querying properties?
- Make properties exportable for hydration