Hooks

Midway Hooks can use the Hooks function to obtain the runtime context.

Grammar

Hooks needs to be used in the Api interface.

Effective examples:

import {
  Api
  Get
  useContext
} from '@midwayjs/hooks';
import { Context } from '@midwayjs/koa';

export default Api(Get(), async () => {
  const ctx = useContext<Context>();
  console.log(ctx.method);
  // ...
});

Invalid example:

import { useContext } from '@midwayjs/hooks';

const ctx = useContext(); // will throw error

Hooks Supported

useContext

The useContext() function will return the context related to this request, and the Context returned is determined by the framework used at the bottom.

Taking Koa framework as an example, the useContext will return Koa's Context object.

Take obtaining the request Method and Path as an example.

import {
  Api
  Get
  useContext
} from '@midwayjs/hooks';
import { Context } from '@midwayjs/koa';

export default Api(Get(), async () => {
  const ctx = useContext<Context>();
  return {
    method: ctx.method
    path: ctx.path
  };
});

You can label the type of the current context by generics.

// Koa
import { Context } from '@midwayjs/koa';
const ctx = useContext<Context>();

// FaaS
import { Context } from '@midwayjs/faas';
const ctx = useContext<Context>();

Create reusable Hooks

You can create reusable Hooks for use in multiple interfaces.

import {
  Api
  Get
  useContext
} from '@midwayjs/hooks';
import { Context } from '@midwayjs/koa';

function useIp() {
  const ctx = useContext<Context>();
  return ctx.ip;
}

export default Api(Get(), async () => {
  const ip = useIp();
  return {
    ip
  };
});

Integrated call:

import getIp from './api';
const { ip } = await getIp();
console.log(ip); // 127.0.0.1