在NodeJS Express框架中处理批处理REST API请求 [英] Processing Batch REST API requests in NodeJS Express framework

问题描述

我正在尝试为我的应用程序实现批处理API，客户端可以向服务器发送一组发送请求，并期望返回单个响应.

I am trying to implement batch API for my application, and the client can send a send a set of request to server and expects a single response back.

在我的MEAN堆栈应用中使用Express框架.我创建了一个批处理API资源，该资源从客户端接收该资源，并应按照请求各部分中提到的URL进行操作.

Using Express framework in my MEAN stack app. I have created a batch API resource that receives this from client and should act as per the URL mentioned in each part of the request.

样品申请正文:

{
    "batchID": "abc123",
    "batchReq": [{
        "id": "1",
        "url": "/api/schoolm/students",
        "method": "GET",
        "value": null
    }, {
        "id": "2",
        "url": "/api/schoolm/teachers",
        "method": "POST",
        "value": {
            "name": "Teacher1",
            "age": 34
        }
    }]
}

这被发送到/api/schoolm/batch

This is sent to /api/schoolm/batch

如何将每个请求从批处理控制器内部重定向到各自的API?

How can I redirect the requests each from inside the batch controller to their respective API?

推荐答案

我的答案是从 clay's 一个>回应.我只是添加我在案例中使用的所有细节.再次谢谢你黏土！

My answer is heavily borrowed/inspired/taken from clay's response. And I am just adding all the details that I have used in my case. Thank you again clay!

首先，这是我的API的结构:

First here's how my API is structured:

/api/schoolm 是父api

然后从那里将请求重定向到子API:

And from there requests are redirected to child APIs:

/api/schoolm/students/
/api/schoolm/teachers/
/api/schoolm/subjects/
...

现在，为了支持批处理操作，我添加了另一个API，该API负责处理所有批处理事务.

Now, to support batch opertaions, I added another API which would be responsible to handle all batch transactions.

/api/schoolm/batch/

典型的批处理请求如下:

A typical batch request would look like:

{
"batchReq":[
  {
    "id":"1",
    "uri": "/api/schoolm/students/",
    "httpMethod": "GET"
  },
  {
    "id":"2",
    "uri": "/api/schoolm/teachers/",
    "httpMethod": "GET"
  }
]
}

位于/api/schoolm/batch 的控制器会验证请求(业务逻辑)并使用参考ID进行响应.

The controller at /api/schoolm/batch validates the request (business logic) and responds back with a reference ID.

var async = require('async');
var httpMocks = require('node-mocks-http');
var shortid = require('shortid');

exports.processBatch = function(batchRequests, callback){


  var batchRes = {};
  var result = {};

  var batchID = shortid.generate();
  result.batchID = batchID;

  async.setImmediate(function () {
    async.eachSeries(batchRequests, function(batchReq, callback){
      var mockRes = httpMocks.createResponse({
        eventEmitter: require('events').EventEmitter
      });

      var reqDetails = _processSubRequest(batchReq);

      _fetchResponse(reqDetails, mockRes);
      mockRes.on('end',function(){
        result[batchReq.id] = mockRes._getData();
        callback(null);
      });

    },function(err){
      console.log(result);
    });
  });

  callback("Your batch request has been accepted. Request ID - "+batchID);
}

function _processSubRequest(batchReq){
  var retValue = {};
  var request = {};
  var uriComp = batchReq.uri.split('/');
  retValue.controller = uriComp[3];

  request.method = batchReq.httpMethod;
  request.url = batchReq.uri;
  request.body = batchReq.body || {};
  request.params = batchReq.params || {};

  if(batchReq.httpMethod == 'GET'){
      if(uriComp.length > 5){
        request.params.id = uriComp[4];
      }
  }else if(batchReq.httpMethod == 'POST'){

  }else{

  }
  retValue.request = request;
  return retValue;
}

function _fetchResponse(reqDetails, mockRes){
   var mockReq  = httpMocks.createRequest(reqDetails.request);
   // proceed to fetch answer from respective controller methods.
   .......................
}

function _prepResponse(result, err, res){
  var data = {};

  if(err) {
    data["error"] = err;
    data["response"] = null;
    return data;
  }else{
    data["error"] = null;
    data["response"] = result;
    return data;
  }
}

批处理完成后，可以将其作为实时通知的一部分发送给用户，也可以存储在DB中以供以后读取.

After the batch processing completes, it can be sent to the user as part of live notification or stored in DB to be read from later.

这篇关于在NodeJS Express框架中处理批处理REST API请求的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！