What is the purpose of policy in Laravel?

In Laravel, policies are a way to organize authorization logic related to a specific model or resource. They provide a clear and consistent way to handle authorization checks for various actions that can be performed on a model, such as viewing, creating, updating, or deleting.

Here's a breakdown of the purpose and benefits of using policies in Laravel:

Resource-Specific Authorization: Policies are typically tied to a specific model, making it clear which authorization checks are related to which resource.

Method-Based Checks: Within a policy, you can define methods for different actions, such as view(), create(), update(), and delete(). This provides a clear structure for defining what checks should be made for each action.

Automatic Policy Resolution: Laravel's service container will automatically resolve and instantiate the correct policy for a given model. This means you don't have to manually create or fetch the policy instance.

Integration with Controllers: Laravel provides a helpful authorize method on controllers, which you can use to check policies. For example,

$this->authorize('view', $post) 

would check the view method on the policy associated with the $post model.

Policy Filters: You can define before and after filters within a policy. These filters run before or after the policy checks and can be used for global checks, such as granting super-admin users access to everything.

Clear Authorization Responses: If a policy check fails, Laravel will automatically throw an AuthorizationException, which can be caught and handled to provide a clear response to the user.

Integration with Gates: While gates are another way to define authorization logic in Laravel, policies can use gates within their methods, allowing for a combination of both approaches if needed.

Easy Testing: Since policies are plain PHP classes with methods, they can be easily tested to ensure the authorization logic is correct.