我已经使用Node/Express创建了一个小API，并试图使用Angularjs拉数据，但由于我的html页面在localhost:8888和节点API在端口3000上监听下运行，我得到了No 'Access-Control-Allow-Origin'。我尝试使用node-http-proxy和Vhosts Apache，但没有太多成功，请参阅下面的完整错误和代码。
XMLHttpRequest无法加载localhost:3000。被请求的资源上没有'Access-Control-Allow-Origin'标头。因此，不允许访问Origin 'localhost:8888'。”
// Api Using Node/Express
var express = require('express');
var app = express();
var contractors = [
{
"id": "1",
"name": "Joe Blogg",
"Weeks": 3,
"Photo": "1.png"
}
];
app.use(express.bodyParser());
app.get('/', function(req, res) {
res.json(contractors);
});
app.listen(process.env.PORT || 3000);
console.log('Server is running on Port 3000')
角码
angular.module('contractorsApp', [])
.controller('ContractorsCtrl', function($scope, $http,$routeParams) {
$http.get('localhost:3000').then(function(response) {
var data = response.data;
$scope.contractors = data;
})
HTML
<body ng-app="contractorsApp">
<div ng-controller="ContractorsCtrl">
<ul>
<li ng-repeat="person in contractors">{{person.name}}</li>
</ul>
</div>
</body>
在NODEJ Restful api的app.js中增加如下代码，以避免在angular 6或其他框架中出现“Access-Control-Allow-Origin”错误
var express = require('express');
var app = express();
var cors = require('cors');
var bodyParser = require('body-parser');
//enables cors
app.use(cors({
'allowedHeaders': ['sessionId', 'Content-Type'],
'exposedHeaders': ['sessionId'],
'origin': '*',
'methods': 'GET,HEAD,PUT,PATCH,POST,DELETE',
'preflightContinue': false
}));
上面的答案对我来说很好，只是我需要将多个域名列入白名单。
此外，top answer还会受到这样一个事实的影响，即OPTIONS请求不是由中间件处理的，您不能自动获得它。
我将白名单域存储为allowed_origins在Express配置中，并根据origin头放置正确的域，因为Access-Control-Allow-Origin不允许指定多个域。
这是我最后得出的结论:
var _ = require('underscore');
function allowCrossDomain(req, res, next) {
res.setHeader('Access-Control-Allow-Methods', 'GET, POST, OPTIONS');
var origin = req.headers.origin;
if (_.contains(app.get('allowed_origins'), origin)) {
res.setHeader('Access-Control-Allow-Origin', origin);
}
if (req.method === 'OPTIONS') {
res.send(200);
} else {
next();
}
}
app.configure(function () {
app.use(express.logger());
app.use(express.bodyParser());
app.use(allowCrossDomain);
});
尝试在你的NodeJS/Express应用程序中添加以下中间件(为了方便起见，我添加了一些注释):
// Add headers before the routes are defined
app.use(function (req, res, next) {
// Website you wish to allow to connect
res.setHeader('Access-Control-Allow-Origin', 'http://localhost:8888');
// Request methods you wish to allow
res.setHeader('Access-Control-Allow-Methods', 'GET, POST, OPTIONS, PUT, PATCH, DELETE');
// Request headers you wish to allow
res.setHeader('Access-Control-Allow-Headers', 'X-Requested-With,content-type');
// Set to true if you need the website to include cookies in the requests sent
// to the API (e.g. in case you use sessions)
res.setHeader('Access-Control-Allow-Credentials', true);
// Pass to next layer of middleware
next();
});
(您可能需要使用127.0.0.1而不是localhost。)
应答码只允许localhost:8888。此代码不能部署到生产环境中，也不能部署到不同的服务器和端口名称中。
要让它适用于所有源，请使用下面的代码:
// Add headers
app.use(function (req, res, next) {
// Website you wish to allow to connect
res.setHeader('Access-Control-Allow-Origin', '*');
// Request methods you wish to allow
res.setHeader('Access-Control-Allow-Methods', 'GET, POST, OPTIONS, PUT, PATCH, DELETE');
// Request headers you wish to allow
res.setHeader('Access-Control-Allow-Headers', 'X-Requested-With,content-type');
// Set to true if you need the website to include cookies in the requests sent
// to the API (e.g. in case you use sessions)
res.setHeader('Access-Control-Allow-Credentials', true);
// Pass to next layer of middleware
next();
});
