Course Introduction:Dependency injection (DI) is the core mechanism of the Angular framework, which reduces inter-class coupling by providing dependencies externally rather than creating them by itself. 1. DI automatically passes dependency instances through constructor parameters, such as constructor(privateservice:DataService); 2. Angular supports multi-level injectors: root injector (providedIn:'root') provides global singleton services, module/component-level injectors limit service scope; 3. Common injection methods include constructor injection (most commonly used), attribute injection and method parameter injection; 4. Notes include avoiding circular dependencies, preventing duplicate services from causing non-singleton problems, and using APP_I
2025-06-29 comment 0 588
Course Introduction:Dependency injection (DI) makes PHP code easier to test and maintain by reducing tight coupling between components. Its core advantages include: 1. Simplify unit testing, allowing injection of simulated objects to replace real services, avoid side effects, and improve testing speed and reliability; 2. Promote loose coupling, making the class dependency interface rather than concrete implementation, making it easier to independently modify and expand components; 3. Improve reusability and configuration flexibility. The same class can achieve diversified behavior by injecting different dependencies in different contexts, such as the development, production and testing environments using different logging methods. In addition, modern PHP frameworks such as Symfony and Laravel built-in DI containers further simplify the implementation of object management and dependency injection.
2025-06-04 comment 0 518
Course Introduction:Implementing dependency injection (DI) in PHP can be done by manual injection or using DI containers. 1) Manual injection passes dependencies through constructors, such as the UserService class injecting Logger. 2) Use DI containers to automatically manage dependencies, such as the Container class to manage Logger and UserService. Implementing DI can improve code flexibility and testability, but you need to pay attention to traps such as overinjection and service locator anti-mode.
2025-05-07 comment 0 1132
Course Introduction:Service containers and dependency injection containers are often mentioned in the PHP framework. Although they are related, they are different. Dependency injection containers (DICs) focus on automatically parsing class dependencies, such as injecting objects through constructors without manual instantiation. The service container extends its functions on this basis, including binding interfaces to specific implementations, registering singletons, managing shared instances, etc. When using it, if the class dependency resolution or cross-frame scenarios are discussed, it should be called DIC; if it involves service management within the framework, it is called a service container. The two are often integrated in modern frameworks, but understanding their differences can help to gain a deep understanding of the framework mechanism.
2025-06-04 comment 0 816
Course Introduction:The application of SOLID principle in PHP development includes: 1. Single responsibility principle (SRP): Each class is responsible for only one function. 2. Open and close principle (OCP): Changes are achieved through extension rather than modification. 3. Lisch's Substitution Principle (LSP): Subclasses can replace base classes without affecting program accuracy. 4. Interface isolation principle (ISP): Use fine-grained interfaces to avoid dependencies and unused methods. 5. Dependency inversion principle (DIP): High and low-level modules rely on abstraction and are implemented through dependency injection.
2025-04-03 comment 0 1104
Course Elementary 13744
Course Introduction:Scala Tutorial Scala is a multi-paradigm programming language, designed to integrate various features of object-oriented programming and functional programming.
Course Elementary 82260
Course Introduction:"CSS Online Manual" is the official CSS online reference manual. This CSS online development manual contains various CSS properties, definitions, usage methods, example operations, etc. It is an indispensable online query manual for WEB programming learners and developers! CSS: Cascading Style Sheets (English full name: Cascading Style Sheets) is an application used to express HTML (Standard Universal Markup Language).
Course Elementary 13130
Course Introduction:SVG is a markup language for vector graphics in HTML5. It maintains powerful drawing capabilities and at the same time has a very high-end interface to operate graphics by directly operating Dom nodes. This "SVG Tutorial" is intended to allow students to master the SVG language and some of its corresponding APIs, combined with the knowledge of 2D drawing, so that students can render and control complex graphics on the page.
Course Elementary 24578
Course Introduction:In the "AngularJS Chinese Reference Manual", AngularJS extends HTML with new attributes and expressions. AngularJS can build a single page application (SPAs: Single Page Applications). AngularJS is very easy to learn.
Course Elementary 27436
Course Introduction:Go is a new language, a concurrent, garbage-collected, fast-compiled language. It can compile a large Go program in a few seconds on a single computer. Go provides a model for software construction that makes dependency analysis easier and avoids most C-style include files and library headers. Go is a statically typed language, and its type system has no hierarchy. Therefore users do not need to spend time defining relationships between types, which feels more lightweight than typical object-oriented languages. Go is a completely garbage-collected language and provides basic support for concurrent execution and communication. By its design, Go is intended to provide a method for constructing system software on multi-core machines.
Laravel Modal does not return data
2024-03-29 10:31:31 0 1 586
Can I use the automatic generation module of thinkphp5 in Windows 7 system? How to configure and use
2017-10-10 17:04:14 0 2 1379
2017-10-10 19:25:59 0 4 2935
To use mcrypt_get_key_size() in php study, how to enable mcrypt_
2017-10-10 19:47:34 0 1 1167
Detecting login status and preventing repeated login status in TP5 - My page is wrong
2017-10-10 22:49:15 0 0 1180