Policies in Laravel

Policies in Laravel give a structured approach to handling permission logic related to Eloquent models. They are classes that have methods for determining whether a user has permission to do specific activities on a given resource.

Origin

Policies are part of Laravel's strong authorization system. It aims to simplify and consolidate permission logic. It does this by using reusable, model-specific classes.

Why are Policies Used?

1. Promotes Clean Code: Moves authorization logic out of controllers, keeping them lean and focused.
2. Supports Granular Permissions: Gives users exact control over what they can do with certain resources.
3. Integrates Seamlessly: Eloquent models and gates are natively supported. They allow for efficient access control.

Best Practices.

1. Map Policies to Models: Register policies in the 'AuthServiceProvider' to associate them with their corresponding models.
2. Use Gates for Simplicity: Combine policies and gates to handle simple authorization logic that does not require a model.
3. Test Policies Thoroughly: Consider all scenarios to ensure secure, predictable access.

Example in Action

Create a policy:

php artisan make:policy PostPolicy --model=Post

Define a policy method:

public function update(User $user, Post $post)
{
    return $user->id === $post->user_id;
}

Register the policy in AuthServiceProvider:

protected $policies = [
    Post::class => PostPolicy::class,
];

Authorize an action in a controller:

$this->authorize('update', $post);