@yhiot/utils/src/koamw/routerRestful.js

基本工具集

/**
 * Koa-Router的中间件,预处理restful-url的参数.
 * 处理如下格式URL:
  // router.get('/user', getUsers);
  // router.get('/user/:_id', getUser);
  // router.put('/user/:_id', updateUser);
  // router.delete('/user/:_id', removeUser);
  // router.post('/user', createUser);
 * GET类型分两种:
  + 有_id的表示获取单个
  + 无_id表示查询多个
 * PUT类型只有一种: 更新单个
 * POST类型只有一种: 创建单个
 * DELETE类型只有一种: 删除单个
 */
import Errcode, { EC } from '../Errcode';
import { memParse as parseQueryString } from '@yhiot/dbcached';

export function preRestfulCreator(prefix) {
  if (!prefix) prefix = '';
  return async function preRestful(ctx, next) {
    let path = ctx.path;
    if (!path.startsWith(prefix)) {
      // 非prefix开头,不用处理.
      return await next();
    }
    let subpath = path.substring(prefix.length);
    let fields = subpath.split('/') || [];
    let method = ctx.method;
    switch (method) {
      case 'GET': {
        let _id = fields[1];

        let qstr = ctx.request.querystring;
        if (qstr) {
          qstr = decodeURIComponent(qstr);
        }
        if (qstr && qstr.startsWith('?')) {
          qstr = qstr.substr(1);
        }
        let options = parseQueryString(qstr);

        if (!_id) {
          // 无_id表示查列表
          ctx.state._type = 'retrieve';
        } else {
          ctx.state._type = 'get';
        }
        ctx.state._id = _id;
        ctx.state._options = options;
        break;
      }
      case 'POST': {
        let args = ctx.request.body;
        if (!args) {
          throw new Errcode('error! args is null', EC.ERR_PARAM_ERROR);
        }

        ctx.state._type = 'create';
        ctx.state._args = args;
        break;
      }
      case 'PUT': {
        let _id = fields[1];
        let args = ctx.request.body;
        if (!_id) {
          throw new Errcode('error! _id is null', EC.ERR_PARAM_ERROR);
        }
        if (!args) {
          throw new Errcode('error! args is null', EC.ERR_PARAM_ERROR);
        }

        ctx.state._type = 'update';
        ctx.state._id = _id;
        ctx.state._args = args;
        break;
      }
      case 'DELETE': {
        let _id = fields[1];
        if (!_id) {
          throw new Errcode('error! _id is null', EC.ERR_PARAM_ERROR);
        }

        ctx.state._type = 'remove';
        ctx.state._id = _id;
        break;
      }
      default:
        ctx.state._type = 'none';
        break;
    }
    return await next();
  };
}

export function postRestfulCreator(restfulFunction) {
  return async function restfulResult(ctx) {
    let result = await restfulFunction(ctx.state);
    ctx.body = {
      errcode: 0,
      result,
    };
  };
}