ionews / light-service-php
Provides a simple interface to implement complex actions through a serie of simple actions
Requires (Dev)
- phpunit/phpunit: *
- satooshi/php-coveralls: dev-master
This package is not auto-updated.
Last update: 2024-12-21 17:32:58 UTC
README
Small piece of software intended to enforce SRP on PHP apps, thought to be "light" and not use any dependencies. Heavily based on the ideas proposed by two ruby gems:
Concept
Each action should have a single responsibility that must be implemented in the perform
method. An action can access databases, send emails, call services and etc.
When an action is executed, it receives a context which can be read and modified.
To perform more complex operations you must use an organizer chaining multiple actions, which will share the same context during execution. In fact, an organizer is nothing more than an action with a specific implementation, meaning that an action and an organizer share the very same interface. This is useful so you can include an organizer as an action inside another organizer.
Action examples:
class GenerateRandomPassword extends Action { protected function perform() { $length = 8; $chars = '0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ'; $password = ''; for ($i = 0; $i < $length; $i++) { $password .= $chars[rand(0, strlen($chars) - 1)]; } $this->context->password = $password; } } class UpdateUserPassword extends Action { protected function perform() { $user_id = $this->context->user_id; $password = $this->context->password; // access the database using the method of your choice and update the password } }
Organizer example:
class ResetUserPassword extends Organizer { protected $organize = ['GenerateRandomPassword', 'UpdateUserPassword', 'EmailUserWithPassword']; }
Call example (from a MVC controller):
class UserController extends BaseController { public function resetPassword() { $result = ResetUserPassword::execute(['user_id' => $this->request->id]); if ($result->success()) { // use $result->getContext() to access the results and redirect the app } else { // error, use $result->getFailureMessage() to access any failure message } } }
Keep in mind that you shouldn't use this approach everywhere in your app, but only in the really complex parts of it.
Fail, Halt and Exceptions
An action may fail, meaning that it couldn't achieve its goal. To make an action fail just call the fail
method (optionally passing a message).
class SomeAction extends Action { protected function perform() { $this->fail('Oh noes'); } } $result = SomeAction::execute([]); $result->success(); // false $result->failure(); // true $result->halted(); // false $result->getFailureMessage(); // 'Oh noes'
If the action is executing inside an organizer and fails, it will prevent the execution of the subsequents actions.
If an action implements a rollback
method, it will be called after a subsequent action fails. Example: if EmailUserWithPassword
fails to send an e-mail to the user, we could implement an rollback
method in the UpdateUserPassword
to undo the update. Inside the rollback
method you can access the context in the same way as in perform
.
class UpdateUserPassword extends Action { protected function perform() { $user_id = $this->context->user_id; $password = $this->context->password; // access the database using the method of your choice and update the password } protected function rollback() { // undo the update password } }
You shouldn't re-implement the rollback
method of an organizer, unless you really know what you're doing.
It's possible to stop the execution chain without fail: using halt
. Basically it will prevent any subsequent actions of execute, but the result remains a success. You can test if an action/organizer was halted using the halted
method.
class SomeAction extends Action { protected function perform() { $this->halt(); } } $result = SomeAction::execute([]); $result->success(); // true $result->failure(); // false $result->halted(); // true
All exceptions that occur when performing an action are caught automatically and passed to the caught
method. By default, actions re-throw then, on the other hand, organizers first call the rollback
method before re-throwing. This is done so all performed actions are rolled back before the exception propagation. You can change this behaviour re-implementing the caught
method.
Before and After
A before
method can be implemented if you need to do any setup pre-execution. If the fail
method is called inside the before
, perform
will never be called.
In the same way, an after
method can be implemented so you can do any cleanup, but keep in mind that if before
or perform
fails it will never be called.
class SomeAction extends Action { protected function before() { // any setup } protected function perform() { // perform } protected function after() { // cleanup } }
Expects and Promises
Expectations and promises can be defined for each action. If an action has a set of expectations, it will automatically fails if these aren't met.
class UpdateUserPassword extends Action { protected $expects = ['user_id', 'password']; protected function perform() { $user_id = $this->context->user_id; $password = $this->context->password; // access the database using the method of your choice and update the password } } $result = UpdateUserPassword::execute(['user_id' => 1]); $result->success(); // false $result->getFailureMessage(); // 'Expectations were not met'
Similarly, an action will fail if a set of promises are defined and these are not present in the context at the end of execution.
class GenerateRandomPassword extends Action { protected $promises = ['password']; protected function perform() { $length = 8; $chars = '0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ'; $password = ''; for ($i = 0; $i < $length; $i++) { $password .= $chars[rand(0, strlen($chars) - 1)]; } //$this->context->password = $password; } } $result = GenerateRandomPassword::execute([]); $result->success(); // false $result->getFailureMessage(); // 'Promises were not met'
This feature is particularly useful so you can explicitly define the interface between the actions.
Iterator Action
It's an action that will be performed over an array.
class SomeAction extends IteratorAction { protected $over = 'key_of_the_array_in_context' protected function each($key, $value) { ... } }
Requirements
- PHP 5.3+
Installation and Usage
Contributing
You know the drill!
License
Released under GPLv2