如何使用 node.js 后端服务器与前端和 mongolab 数据库进行交互？

Question

我正在构建一个具有简单 jquery/html/css 前端和 node.js 服务器后端的网站。如果我的前端具有从服务器请求用户信息的功能，如下所示：

function requestUser(email, password) {
    xmlhttp = new XMLHttpRequest();
    xmlhttp.open("GET", "http://localhost:8888/getUser/" + email + "/" + password, true);
    xmlhttp.onreadystatechange = function() {
        if (xmlhttp.readyState == 4 && xmlhttp.status == 200) {
           console.log(xmlhttp.responseText);
        }
    }
    xmlhttp.send();
}

我的节点服务器看起来像这样：

var http = require("http"),
    mongojs = require("mongojs"),
    fs = require("fs"),
    url = require("url");
    express = require("express")
var server = http.createServer(requestHandler);
server.listen(8888);
var uri = "mongodb://<dbuser>:<dbpassword>@ds036698.mongolab.com:36698/alirodatabase";
var db = mongojs(uri, ["Papers", "Users"]);
console.log("node server running back end of app");
function requestHandler(request, response) {
    //request for user is .../getUser/<username>/<password>
    var path = url.parse(request.url).pathname;
    var details = path.split('/');
    if(details.indexOf("getUser") != -1) {
        console.log("recieved request for user");
        var user = db.Users.find({"email": details[details.indexOf("getUser") + 1],
                                  "password": details[details.indexOf("getUser") + 2]});
        user = user.toArray[0];
        response.writeHead(200, {"Content-Type": "text/json"});
        response.write(JSON.stringify(user));
    }
    else {
        fs.readFile("./index.html", function(err, file) {
            if(err) {
                return 
            }
            response.writeHead(200, {"Content-Type": "text/html"});
            response.end(file, "utf-8");
        });
    }
}

为什么它不起作用？当我尝试从服务器请求时，我从 firefox 收到 'mixed content' and/or 'corss-origin' 错误。如何让节点服务器运行与站点的其余部分位于同一域中以避免这些错误？

Answer 1

真的很难阅读你的代码，我明白你想做什么，但让我先建议一个更好的结构，更容易阅读，理解并为你的服务器实现更多路由，请检查这里：

var express = require('express'),
  cors = require('cors'),
  app = express();

app.use(cors());

app.get('/getUser/:user/:passwd', function(req, res, next) {
  // Perform all mongo operations here using req.params.user and req.params.passwd
  // and in the callback send a response like the object below
  res.json({
    msg: 'This is CORS-enabled for all origins!',
    user: req.params.user,
    passwd: req.params.passwd
  });
});

app.listen(8888, function() {
  console.log('CORS-enabled web server listening on port 8888');
});

还缺少 CORS 支持（https://developer.mozilla.org/en-US/docs/Web/HTTP/Access_control_CORS) as you will need this in your use case for if you are planning to host serve static files consuming this service hosted in a different server, so lets use this module: https://www.npmjs.com/package/cors 它将允许 express 从任何地方处理请求。

如何使用 node.js 后端服务器与前端和 mongolab 数据库进行交互？

How to use a node.js back-end server to interact with the front-end and a mongolab database?

javascript

node.js

mongodb

web

mlab