There are three ways to add custom validation rules in Laravel: using closures, Rule classes, and form requests. 1. Use closures to be suitable for lightweight verification, such as preventing the user name "admin"; 2. Create Rule classes (such as ValidUsernameRule) to make complex logic clearer and maintainable; 3. Integrate multiple rules in form requests and centrally manage verification logic. At the same time, you can set prompts through custom messages methods or incoming error message arrays to improve flexibility and maintainability.

ToworkeffectivelywithpivottablesinLaravel,firstaccesspivotdatausingwithPivot()orwithTimestamps(),thenupdateentrieswithupdateExistingPivot(),managerelationshipsviadetach()andsync(),andusecustompivotmodelswhenneeded.1.UsewithPivot()toincludespecificcol

Laravelprovidesacleanandflexiblewaytosendnotificationsviamultiplechannelslikeemail,SMS,in-appalerts,andpushnotifications.Youdefinenotificationchannelsinthevia()methodofanotificationclass,andimplementspecificmethodsliketoMail(),toDatabase(),ortoVonage

Dependency injection automatically handles class dependencies through service containers in Laravel without manual new objects. Its core is constructor injection and method injection, such as automatically passing in the Request instance in the controller. Laravel parses dependencies through type prompts and recursively creates the required objects. The binding interface and implementation can be used by the service provider to use the bind method, or singleton to bind a singleton. When using it, you need to ensure type prompts, avoid constructor complications, use context bindings with caution, and understand automatic parsing rules. Mastering these can improve code flexibility and maintenance.

Laravel performance optimization can improve application efficiency through four core directions. 1. Use the cache mechanism to reduce duplicate queries, store infrequently changing data through Cache::remember() and other methods to reduce database access frequency; 2. Optimize database from the model to query statements, avoid N 1 queries, specifying field queries, adding indexes, paging processing and reading and writing separation, and reduce bottlenecks; 3. Use time-consuming operations such as email sending and file exporting to queue asynchronous processing, use Supervisor to manage workers and set up retry mechanisms; 4. Use middleware and service providers reasonably to avoid complex logic and unnecessary initialization code, and delay loading of services to improve startup efficiency.

Methods to manage database state in Laravel tests include using RefreshDatabase, selective seeding of data, careful use of transactions, and manual cleaning if necessary. 1. Use RefreshDatabasetrait to automatically migrate the database structure to ensure that each test is based on a clean database; 2. Use specific seeds to fill the necessary data and generate dynamic data in combination with the model factory; 3. Use DatabaseTransactionstrait to roll back the test changes, but pay attention to its limitations; 4. Manually truncate the table or reseed the database when it cannot be automatically cleaned. These methods are flexibly selected according to the type of test and environment to ensure the reliability and efficiency of the test.

LaravelSanctum is suitable for simple, lightweight API certifications such as SPA or mobile applications, while Passport is suitable for scenarios where full OAuth2 functionality is required. 1. Sanctum provides token-based authentication, suitable for first-party clients; 2. Passport supports complex processes such as authorization codes and client credentials, suitable for third-party developers to access; 3. Sanctum installation and configuration are simpler and maintenance costs are low; 4. Passport functions are comprehensive but configuration is complex, suitable for platforms that require fine permission control. When selecting, you should determine whether the OAuth2 feature is required based on the project requirements.

Laravel simplifies database transaction processing with built-in support. 1. Use the DB::transaction() method to automatically commit or rollback operations to ensure data integrity; 2. Support nested transactions and implement them through savepoints, but it is usually recommended to use a single transaction wrapper to avoid complexity; 3. Provide manual control methods such as beginTransaction(), commit() and rollBack(), suitable for scenarios that require more flexible processing; 4. Best practices include keeping transactions short, only using them when necessary, testing failures, and recording rollback information. Rationally choosing transaction management methods can help improve application reliability and performance.