jcfrane/policy

A simple and naive policy implementation

v0.1.0 2018-03-28 06:14 UTC

Requires

• php: >=7.0

Requires (Dev)

• phpunit/phpunit: ^5.2

MIT

• JC Frane

• php
• Policy

README

A naive and simple implementation for Policy classes.

Benefits

• Avoid nested if's in your code.
• Aggregate conditional logic in once place.

How to use?

Create a class that extends AbstractPolicy

use JcFrane\Policy\AbstractPolicy;

class BlogPolicy extends AbstractPolicy
{

}

Create methods inside the your Policy class that represent each conditional logic for the said policy.

use JcFrane\Policy\AbstractPolicy;

class BlogPolicy extends AbstractPolicy
{
    public function canCreate($subject)
    {
        $this->allow($subject->canCreate, 'Cannot create a subject.');
    }

    public function canView($subject)
    {
        $this->allow($subject->canView, 'Cannot view the subject.');
    }

    public function canDelete($subject)
    {
        $this->forbid($subject->canDelete, 'Cannot delete the subject.');
    }

    public function canUpdate($subject)
    {
        $this->forbid($subject->canUpdate, 'Cannot update the subject');
    }
}

Evaluate your Policy Class

use JcFrane\Polcy\PolicyChecker;

use Some\Namespace\BlogPolicy;

$checker = new PolicyChecker();

$subject = new \stdClass();
$subject->canCreate = true;
$subject->canView = false;
$subject->canDelete = true;
$subject->canUpdate = false;

$result = $checker->check(BlogPolicy::class, $subject, 'create'); // returns true

$result = $checker->check(BlogPolicy::class, $subject, 'view'); // throws JcFrane/PolicyViolationException

$result = $checker->check(BlogPolicy::class, $subject, 'delete'); // returns true

$result = $checker->check(BlogPolicy::class, $subject, 'update'); // throws JcFrane/PolicyViolationException

That's it! You can now create multiple policy classes that aggregates your conditional logic inside your code.

The allow() and forbid() methods

The allow() accepts a boolean and a violation message. If first argument is true, then the check() will return true. Otherwise, will throw a ViolationException.

The forbid() accepts a boolean and a violation message. If first argument is false, then the check() will throw a ViolationException. Otherwise, will return true.

Installation

$ composer install jcfrane/policy