云函数挂载在 init ,后续还可以继续扩展
import FunctionContext from '@lafjs/cloud'
interface Middleware {
(ctx: FunctionContext, next: () => Promise<void>): Promise<void>;
}
function compose(middlewares: Middleware[]) {
return async (ctx: FunctionContext) => {
const exec = async (index: number) => {
if (index === middlewares.length) return;
const middleware = middlewares[index];
const next = () => exec(index + 1);
await middleware(ctx, next);
};
return exec(0);
}
}
const logger: Middleware = async (ctx, next) => {
console.log('logger')
next()
};
const auth: Middleware = async (ctx, next) => {
console.log('auth')
next()
};
const app = compose([logger, auth]);
export default async function (ctx: FunctionContext) {
await app(ctx);
// main logic
}
demo: 在中间件模式中,context对象是各个中间件共享的,可以用来在中间件之间传递数据和信息。
const logger: Middleware = async (ctx, next) => {
// 在ctx中写入用户信息
ctx.user = ['adds'];
console.log('logger')
next()
};
const auth: Middleware = async (ctx, next) => {
console.log('auth')
console.log(ctx.user)
next()
};
[2023-07-18 11:30:07]
'logger'
[2023-07-18 11:30:07]
'auth'
[2023-07-18 11:30:07]
[ 'adds' ]
代码比较粗犷，后续再封装优化