服务
¥Services
服务是一组可重用的功能。它们对于尊重 "不要重复自己" (DRY) 编程概念和简化 controllers 逻辑特别有用。
¥Services are a set of reusable functions. They are particularly useful to respect the "don’t repeat yourself" (DRY) programming concept and to simplify controllers logic.
![Simplified Strapi backend diagram with services highlighted](/img/assets/backend-customization/diagram-controllers-services.png)
执行
¥Implementation
服务可以 手动生成或添加。Strapi 提供了 createCoreService
工厂功能,可自动生成核心服务并允许构建自定义服务或 扩展或替换生成的服务。
¥Services can be generated or added manually. Strapi provides a createCoreService
factory function that automatically generates core services and allows building custom ones or extend or replace the generated services.
添加新服务
¥Adding a new service
可以实现一个新的服务:
¥A new service can be implemented:
-
¥with the interactive CLI command
strapi generate
-
或通过在适当的文件夹中手动创建 JavaScript 文件(参见 项目结构):
¥or manually by creating a JavaScript file in the appropriate folder (see project structure):
-
./src/api/[api-name]/services/
用于 API 服务¥
./src/api/[api-name]/services/
for API services -
或
./src/plugins/[plugin-name]/services/
对应 插件服务。¥or
./src/plugins/[plugin-name]/services/
for plugin services.
-
要手动创建服务,请导出返回服务实现的工厂函数(即具有方法的对象)。该工厂函数接收 strapi
实例:
¥To manually create a service, export a factory function that returns the service implementation (i.e. an object with methods). This factory function receives the strapi
instance:
- JavaScript
- TypeScript
const { createCoreService } = require('@strapi/strapi').factories;
module.exports = createCoreService('api::restaurant.restaurant', ({ strapi }) => ({
// Method 1: Creating an entirely new custom service
async exampleService(...args) {
let response = { okay: true }
if (response.okay === false) {
return { response, error: true }
}
return response
},
// Method 2: Wrapping a core service (leaves core logic in place)
async find(...args) {
// Calling the default core controller
const { results, pagination } = await super.find(...args);
// some custom logic
results.forEach(result => {
result.counter = 1;
});
return { results, pagination };
},
// Method 3: Replacing a core service
async findOne(documentId, params = {}) {
return strapi.documents('api::restaurant.restaurant').findOne(documentId, this.getFetchParams(params));
}
}));
import { factories } from '@strapi/strapi';
export default factories.createCoreService('api::restaurant.restaurant', ({ strapi }) => ({
// Method 1: Creating an entirely custom service
async exampleService(...args) {
let response = { okay: true }
if (response.okay === false) {
return { response, error: true }
}
return response
},
// Method 2: Wrapping a core service (leaves core logic in place)
async find(...args) {
// Calling the default core controller
const { results, pagination } = await super.find(...args);
// some custom logic
results.forEach(result => {
result.counter = 1;
});
return { results, pagination };
},
// Method 3: Replacing a core service
async findOne(documentId, params = {}) {
return strapi.documents('api::restaurant.restaurant').findOne(documentId, this.getFetchParams(params));
}
}));
要开始创建你自己的服务,请参阅 文档服务 API 文档中的 Strapi 内置函数。
¥To get started creating your own services, see Strapi's built-in functions in the Document Service API documentation.
Example of a custom email service (using Nodemailer)
当创建新的 content-type 时,Strapi 会使用占位符代码构建通用服务,准备进行自定义。
¥When a new content-type is created, Strapi builds a generic service with placeholder code, ready to be customized.
拓展核心服务
¥Extending core services
核心服务是为每种内容类型创建的,controllers 可以使用核心服务通过 Strapi 项目执行可重用逻辑。可以定制核心服务来实现你自己的逻辑。以下代码示例应该可以帮助你入门。
¥Core services are created for each content-type and could be used by controllers to execute reusable logic through a Strapi project. Core services can be customized to implement your own logic. The following code examples should help you get started.
核心服务可以完全替换为 创建定制服务,并将其命名为与核心服务相同的名称(例如 find
、findOne
、create
、update
或 delete
)。
¥A core service can be replaced entirely by creating a custom service and naming it the same as the core service (e.g. find
, findOne
, create
, update
, or delete
).
Collection type examples
Single type examples
用法
¥Usage
创建服务后,可以从 controllers 或其他服务访问它:
¥Once a service is created, it's accessible from controllers or from other services:
// access an API service
strapi.service('api::apiName.serviceName').FunctionName();
// access a plugin service
strapi.service('plugin::pluginName.serviceName').FunctionName();
在上面的语法示例中,serviceName
是 API 服务的服务文件的名称,或者用于将服务文件导出到 services/index.js
的插件服务的名称。
¥In the syntax examples above, serviceName
is the name of the service file for API services or the name used to export the service file to services/index.js
for plugin services.
要列出所有可用服务,请运行 yarn strapi services:list
。
¥To list all the available services, run yarn strapi services:list
.