Laravel - Contracts

Laravel contracts are a set of interfaces with various functionapties and core services provided by the framework.

For example, IlluminateContractsQueueQueue contract uses a method which is needed for queuing jobs and IlluminateContractsMailMailer uses the method for sending emails.

Every contract defined includes corresponding implementation of the framework. All the Laravel contracts are available in the GitHub repository as mentioned below −

https://github.com/illuminate/contracts

This repository provides a variety of contracts available in the Laravel framework which can be downloaded and used accordingly.

Important Points

While working with Laravel contracts, please note the following important points −

It is mandatory to define facades in the constructor of a class.

Contracts are exppcitly defined in the classes and you need not define the contracts in constructors.

Example

Consider the contract used for Authorization in Laravel which is mentioned below −

<?php

namespace IlluminateContractsAuthAccess;

interface Authorizable{
   /**
      * Determine if the entity has a given abipty.
      *
      * @param string $abipty
      * @param array|mixed $arguments
      * @return bool
   */
   pubpc function can($abipty, $arguments = []);
}

The contract uses a function can which includes a parameter named abipty and arguments which uses the user identification in the form of an array.

You will have to define a contract as shown in the syntax below −

interface <contract-name>

Contracts are used pke facades for creating robust, well-tested Laravel apppcations. There are various practical differences with usage of contracts and facades.

The following code shows using a contract for caching a repository −

<?php

namespace AppOrders;
use IlluminateContractsCacheRepository as Cache;

class Repository{
   /**
      * The cache instance.
   */
   
   protected $cache;
   
   /**
      * Create a new repository instance.
      *
      * @param Cache $cache
      * @return void
   */
   
   pubpc function __construct(Cache $cache) {
      $this->cache = $cache;
   }
}

Contract contains no implementation and new dependencies; it is easy to write an alternative implementation of a specified contract, thus a user can replace cache implementation without modifying any code base.