Contracts is a contract in Laravel that defines the core service interface. It is essentially a PHP interface, which is used to decouple component dependencies. 1. They are stored in the illuminate/contracts package, and each Contract defines the methods that a specific service should have, such as the Kernel that handles HTTP requests and the Repository that caches operations. 2. The benefits of using Contracts include decoupling, interchangeability, and ease of testing, such as replacing the default cache system by implementing an interface, or isolating external dependencies with a Mock object in testing. 3. The usage method is to parse the interface through the service container and bind the specific implementation, such as binding the interface to a custom class in the service provider's register method. 4. Common Laravel Contracts include Container, Dispatcher, Responsable, Queue and Mailer, etc., which are distributed in different modules for on-demand introduction.
Contracts in Laravel are a set of contracts that define the framework's core service interfaces. They are essentially PHP interfaces that decouple the dependencies between different components inside Laravel. Using Contracts allows you to have a clearer understanding of what functions each service should provide, and facilitate testing and replacement implementation.

What are Contracts?
Contracts is some interface files placed in the independent package of illuminate/contracts
. Each Contract defines a method that a specific service should have. For example, Illuminate\Contracts\Http\Kernel
is responsible for handling HTTP requests, Illuminate\Contracts\Cache\Repository
is responsible for caching operations.
Many classes inside the Laravel framework are designed based on these interfaces, rather than relying directly on specific implementations. The advantage of this is that you can easily replace the specific implementation of a certain service without affecting other code.

Why use Contracts?
Many people will wonder when they first come into contact with Laravel: Why use interfaces? Isn't it easier to call classes directly? In fact, the value of Contracts is mainly reflected in the following points:
- Decoupling : Through interface programming, classes do not depend on specific implementations, but only rely on interfaces, making it easier to maintain and extend.
- Substitutability : For example, you can use your own cache implementation to replace Laravel's default cache system, and you only need to implement the corresponding Contract interface.
- Easy to test : In unit testing, external dependencies can be isolated through the Mock interface to improve testing efficiency.
For example, if you write a service class that relies on Illuminate\Contracts\Cache\Repository
interface, then you can pass in a fake cache implementation during testing without actually accessing Redis or file system.

How to use Contracts?
The way to use Contract is to parse the interface through the service container and obtain the corresponding service instance. For example:
use Illuminate\Contracts\Cache\Repository; class SomeService { protected $cache; public function __construct(Repository $cache) { $this->cache = $cache; } public function getData() { return $this->cache->get('key'); } }
In this example, SomeService
does not know whether $cache
uses File cache or Redis cache, as long as it implements Repository
interface.
If you want to customize a Contract implementation, you can do this:
- Implement this interface
- Bind interface to your implementation class in the service provider
For example, in register()
method of the service provider:
$this->app->bind( 'Illuminate\Contracts\Cache\Repository', 'App\Services\MyCustomCache' );
In this way, your custom implementation will be automatically used wherever you use this interface in the entire application.
What are the common Laravel Contracts?
Laravel provides a lot of built-in Contracts, common ones include:
-
Illuminate\Contracts\Container\Container
: Service container interface -
Illuminate\Contracts\Events\Dispatcher
: Event Scheduler -
Illuminate\Contracts\Routing\Responsable
: Response generation interface -
Illuminate\Contracts\Queue\Queue
: Queue interface -
Illuminate\Contracts\Mail\Mailer
: Mail sending interface
These interfaces are distributed in different modules and can be introduced and used as needed.
Basically that's it. Laravel's Contracts may seem a bit abstract, but it's very practical, especially when building large applications or projects that require high maintenance, which can provide a lot of convenience.
The above is the detailed content of What are Laravel Contracts?. For more information, please follow other related articles on the PHP Chinese website!

Hot AI Tools

Undress AI Tool
Undress images for free

Undresser.AI Undress
AI-powered app for creating realistic nude photos

AI Clothes Remover
Online AI tool for removing clothes from photos.

Clothoff.io
AI clothes remover

Video Face Swap
Swap faces in any video effortlessly with our completely free AI face swap tool!

Hot Article

Hot Tools

Notepad++7.3.1
Easy-to-use and free code editor

SublimeText3 Chinese version
Chinese version, very easy to use

Zend Studio 13.0.1
Powerful PHP integrated development environment

Dreamweaver CS6
Visual web development tools

SublimeText3 Mac version
God-level code editing software (SublimeText3)

There are three main ways to set environment variables in PHP: 1. Global configuration through php.ini; 2. Passed through a web server (such as SetEnv of Apache or fastcgi_param of Nginx); 3. Use putenv() function in PHP scripts. Among them, php.ini is suitable for global and infrequently changing configurations, web server configuration is suitable for scenarios that need to be isolated, and putenv() is suitable for temporary variables. Persistence policies include configuration files (such as php.ini or web server configuration), .env files are loaded with dotenv library, and dynamic injection of variables in CI/CD processes. Security management sensitive information should be avoided hard-coded, and it is recommended to use.en

Laravel's configuration cache improves performance by merging all configuration files into a single cache file. Enabling configuration cache in a production environment can reduce I/O operations and file parsing on each request, thereby speeding up configuration loading; 1. It should be enabled when the application is deployed, the configuration is stable and no frequent changes are required; 2. After enabling, modify the configuration, you need to re-run phpartisanconfig:cache to take effect; 3. Avoid using dynamic logic or closures that depend on runtime conditions in the configuration file; 4. When troubleshooting problems, you should first clear the cache, check the .env variables and re-cache.

When choosing a suitable PHP framework, you need to consider comprehensively according to project needs: Laravel is suitable for rapid development and provides EloquentORM and Blade template engines, which are convenient for database operation and dynamic form rendering; Symfony is more flexible and suitable for complex systems; CodeIgniter is lightweight and suitable for simple applications with high performance requirements. 2. To ensure the accuracy of AI models, we need to start with high-quality data training, reasonable selection of evaluation indicators (such as accuracy, recall, F1 value), regular performance evaluation and model tuning, and ensure code quality through unit testing and integration testing, while continuously monitoring the input data to prevent data drift. 3. Many measures are required to protect user privacy: encrypt and store sensitive data (such as AES

To enable PHP containers to support automatic construction, the core lies in configuring the continuous integration (CI) process. 1. Use Dockerfile to define the PHP environment, including basic image, extension installation, dependency management and permission settings; 2. Configure CI/CD tools such as GitLabCI, and define the build, test and deployment stages through the .gitlab-ci.yml file to achieve automatic construction, testing and deployment; 3. Integrate test frameworks such as PHPUnit to ensure that tests are automatically run after code changes; 4. Use automated deployment strategies such as Kubernetes to define deployment configuration through the deployment.yaml file; 5. Optimize Dockerfile and adopt multi-stage construction

Laravel's EloquentScopes is a tool that encapsulates common query logic, divided into local scope and global scope. 1. The local scope is defined with a method starting with scope and needs to be called explicitly, such as Post::published(); 2. The global scope is automatically applied to all queries, often used for soft deletion or multi-tenant systems, and the Scope interface needs to be implemented and registered in the model; 3. The scope can be equipped with parameters, such as filtering articles by year or month, and corresponding parameters are passed in when calling; 4. Pay attention to naming specifications, chain calls, temporary disabling and combination expansion when using to improve code clarity and reusability.

User permission management is the core mechanism for realizing product monetization in PHP development. It separates users, roles and permissions through a role-based access control (RBAC) model to achieve flexible permission allocation and management. The specific steps include: 1. Design three tables of users, roles, and permissions and two intermediate tables of user_roles and role_permissions; 2. Implement permission checking methods in the code such as $user->can('edit_post'); 3. Use cache to improve performance; 4. Use permission control to realize product function layering and differentiated services, thereby supporting membership system and pricing strategies; 5. Avoid the permission granularity is too coarse or too fine, and use "investment"

To build a PHP content payment platform, it is necessary to build a user management, content management, payment and permission control system. First, establish a user authentication system and use JWT to achieve lightweight authentication; second, design the backend management interface and database fields to manage paid content; third, integrate Alipay or WeChat payment and ensure process security; fourth, control user access rights through session or cookies. Choosing the Laravel framework can improve development efficiency, use watermarks and user management to prevent content theft, optimize performance requires coordinated improvement of code, database, cache and server configuration, and clear policies must be formulated and malicious behaviors must be prevented.

The core idea of PHP combining AI for video content analysis is to let PHP serve as the backend "glue", first upload video to cloud storage, and then call AI services (such as Google CloudVideoAI, etc.) for asynchronous analysis; 2. PHP parses the JSON results, extract people, objects, scenes, voice and other information to generate intelligent tags and store them in the database; 3. The advantage is to use PHP's mature web ecosystem to quickly integrate AI capabilities, which is suitable for projects with existing PHP systems to efficiently implement; 4. Common challenges include large file processing (directly transmitted to cloud storage with pre-signed URLs), asynchronous tasks (introducing message queues), cost control (on-demand analysis, budget monitoring) and result optimization (label standardization); 5. Smart tags significantly improve visual
