Business Logic Bundle

The BusinessLogicBundle helps you to create and to implement your business rules.

Installation

Step 1: Download the Bundle

Open a command console, enter your project directory and execute:

$ composer require nicolasjourdan/business-logic-bundle

Step 2: Enable the Bundle

Then, enable the bundle by adding it to the list of registered bundles in the config/bundles.php file of your project:

// config/bundles.php

return [
    // ...
    NicolasJourdan\BusinessLogicBundle\NicolasJourdanBusinessLogicBundle::class => ['all' => true],
];

Documentation

The source of the documentation is stored in the Resources/doc/ folder in this bundle. The full documentation is here.

This bundle implements 3 design patterns (Specification, Rules and Chain of responsibility) in order to define a system to help you to create your own business rules.

There are 3 important objects in this conception :

• Specification : This is your business condition. It is used to define if a business rule has to be executed on the current candidate.
• Rule : This is your business rule.
• RulesEngine : This object contains several rules and executes ones which have to be executed on the current candidate.

Please, feel free to see the demo.

Basic Usage

Create a Specification

The specification class

<?php

namespace Your\Namespace\Specification;

use NicolasJourdan\BusinessLogicBundle\Service\Specification\CompositeSpecification;

class IsDummySpecification extends CompositeSpecification
{
    public function isSatisfiedBy($candidate): bool
    {
        // Your business condition...
    }
}

You can generate this class with the next command bin/console make:specification IsDummySpecification.

Create a Rule

The rule class

<?php

namespace Your\Namespace\Rule;

use NicolasJourdan\BusinessLogicBundle\Service\Rule\RuleInterface;
use Your\Namespace\Specification\IsDummySpecification;

class DummyRule implements RuleInterface
{
    private const BUSINESS_LOGIC_TAGS = [
        ['rule.user.awesome', 10],
        ['rule.user.another_tag'],
    ];

    /** @var IsDummySpecification */
    private $specification;

    public function __construct(IsDummySpecification $specification)
    {
        $this->specification = $specification;
    }

    public function shouldRun($candidate): bool
    {
        return $this->specification
            ->not()
            ->isSatisfiedBy($candidate);
    }

    public function execute($candidate)
    {
        // Your business rule...
    }
}

Thanks to the private constant BUSINESS_LOGIC_TAGS you can dynamically add tags on your rule. This constant must be an array of arrays. Each array corresponds to a tag. The first argument must be a string and it is corresponding to the tag name. The second one is optional, it must be an integer and it is corresponding to the priority.

You can generate this class with the next command bin/console make:rule DummyRule.

The service declaration

You dont need to declare your rules into the services.yml file thanks to the indication implements RuleInterface. If you decide to declare it into this file, the tags that you defined will be automatically merged with those of the constant.
For instance, the DummyRule will be tagged with : rule.user.vip, rule.user.basic, rule.user.awesome and rule.user.another_tag.

# config/services.yml
    Your\Namespace\Rule\DummyRule:
        arguments:
            $specification: '@Your\Namespace\Specification\IsDummySpecification'
        tags:
            - { name: 'rule.user.vip', priority: 20 } # Tag your rule in order to include it into the related RulesEngine
            - 'rule.user.basic' # You can add several tags to a single rule

Create a RulesEngine

RulesEngine declaration

# config/services.yml
    rules.engine.user.vip:
        class: NicolasJourdan\BusinessLogicBundle\Service\Rule\RulesEngine
        arguments:
            $rules: !tagged rule.user.vip # Get all Rules tagged `rule.user.vip`

Use your created RulesEngine

Your service class

<?php

namespace Your\Namespace\Service;

use NicolasJourdan\BusinessLogicBundle\Service\Rule\RulesEngine;

class Dummy
{
    /** @var RulesEngine */
    private $rulesEngine;

    public function __construct(RulesEngine $rulesEngine)
    {
        $this->rulesEngine = $rulesEngine;
    }

    public function foo(): void
    {
        $candidate = ... 
        
        // The RulesEngine will execute all the business rules which have to be executed on the candidate.
        $updatedCandidate = $this->rulesEngine->execute($candidate);
        
        //...
    }
}

The service declaration

# config/services.yml
    Your\Namespace\Service\Dummy:
        arguments:
            $rulesEngine: '@rules.engine.user.vip'

License

This bundle is under the MIT license. See the complete license in this bundle.