我试图根据数据库查询返回文本 - 用于帐户注册 - 在 $。ajax Success上许多搜索,我无法理解下面的代码。
我找不到如何发送需要异步函数的HTTP响应,如果我尝试这样做,则根本无法处理或检测到该请求。
我认为问题在于我的res.end(" false")调用未及时调用,但代码对我来说是正确的。
我不想使用Express,所有回调都可以正常工作,但是我确定问题在 server.js 我放置注释
上客户端:
$.ajax({
async: true,
dataType: "text",
type: 'POST',
url: 'http://192.168.0.23:3000',
data: JSON.stringify(account_info),
contentType: 'application/json; charset=utf-8',
success: function (res) {
console.log('Account registration : ' + res);
},
complete: function (res) {
console.log('Account registration complete : ' +
JSON.stringify(res));
},
error: function (err) {
console.log(err.responseText)
}
});
服务器端:
server.js
const http = require('http');
var mongoose = require('mongoose');
var Visitor = require('./models/visitor.js');
var Account = require('./models/account.js');
var api = require('./controllers/api.js');
var isExisting = api.isExisting;
var saveData = api.saveData;
const port = 3000;
const server = http.createServer();
console.log('server is listening on ' + port);
server.listen(port);
server.on('request', function (request, response) {
response.setHeader('Access-Control-Allow-Origin', '*');
response.setHeader('Access-Control-Allow-Methods', 'POST');
response.setHeader('Access-Control-Allow-Headers', 'X-Requested-With,content-type');
console.log(request.method);
var body = '';
request.on('data', function (data) {
body += data;
});
request.on('end', function () {
//In case there's content in the POST request
if (body) {
console.log('nRequest content:' + body + 'n');
body = JSON.parse(body);
mongoose.Promise = global.Promise;
mongoose.connect('mongodb://localhost/someDB', {
useMongoClient: true
});
//Pattern = ACCOUNT_REGISTRATION
if (body.pattern == 'account_registration') {
var value = {
email: body.email
}
var new_data = new Account(Account.store(body));
//Check if account_name or website URL already in db
// exist returning the callback
isExisting(Account, value, function (exist) {
console.log(exist);
if (!exist) {
saveData(new_data);
//If you dont remove this line, the request is not detected by nodeJS
response.end('true');
} else {
console.log('nAccount already exist.');
//If you dont remove this line, the request is not detected by nodeJS
response.end('false');
mongoose.connection.close();
}
});
}
}
//Here it's working good but If I remove this line it'll not handle the request at all
response.end('oko');
});
});
api.js
// The API controller
var mongoose = require('mongoose');
//Send some new_data to db
exports.saveData = function (new_data) {
//Data saving into MongoDB database
new_data.save(function (err) {
if (err) {
throw err;
}
console.log('nData successfully added.');
// We need to disconnect now
mongoose.connection.close();
});
}
exports.isExisting = function (ModelName, value, callback) {
ModelName.count(value, function (err, count) {
if (err)
throw err;
if (count == 0)
callback(false);
else
callback(true);
});
}
上次编辑:简而言之,
这是我不删除最后一行时得到的(正常行为,但是我无法获得异步响应
server is listening on 3000
OPTIONS
POST Request content:{"*****"}//real data already in db
true //This is isExisting() callback
Account already exist.
但是,当我删除最后一个响应时。End('oko'),选项之后的所有内容都不会出现...
我现在知道这个问题。
您正在提出CORS请求。所有CORS请求在发送实际请求之前先将选项请求发送到服务器,以检查访问控制标头是否实际允许服务器处理请求。
,由于您的请求处理程序检查是否存在fose.pattern(不存在选项请求),因此响应永远不会发送。
因此,该请求永远不会得到响应,而您的邮政请求永远不会到达服务器,因为它没有从选项请求中获得的权限。
因此,如果添加诸如 if ( method === 'OPTIONS' ) { response.end() } else if ( body ) { ... }
之类的东西,您将确保可以处理选项。
确保确保所有请求都得到回答,即使您只是回答错误或404。