Entity State
, (*1)
Installation
Install with composer require stratadox/entity-state, (*2)
What is this?
This package models the entity state at a certain point in the execution of the
business logic., (*3)
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., (*4)
Additionally, the package comes with a service to extract the state of the entities., (*5)
How to use this?
Step 1: Extract the state of the entities from the Identity Map., (*6)
$originalState = Extract::state()->from($identityMap);
Step 2: Make some changes in the domain., (*7)
$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), (*8)
Step 3: Extract the new state from the entities in the identity map., (*9)
$newState = Extract::state()->from($identityMap);
Step 4: Get the changes since the original state was captured., (*10)
$changes = $newState->changesSince($originalState);
Step 5: Profit., (*11)
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:, (*12)
assert($changes->altered()[0]->properties()[0]->name() === 'Name:userName.name');
If this Name object were contained in an array, the result would look like this:, (*13)
assert($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:, (*14)
$entityState = Extract::stringifying(UuidInterface::class)->from($identityMap);
To do
Potential to-do's:
- Increase performance by hashing properties names?
- Split names into parts?
- Add methods for querying properties?
- Make properties exportable for hydration, (*15)
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Stratadox