nodejs express，ajax 发布 w/jquery 并接收响应
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nodejs express, ajax posting w/ jquery and receiving response
提问by thrice801
Having some trouble getting express to respond properly to my jquery ajax request. The actual posting is working fine, but no matter what I try I cant seem to actually get a data response from my app that I can use. At first it was just posting and hanging constantly, and like a minute later it would respond with an alert that said something like "XML Document loaded" (have no idea where it was coming from) -- Anyways, now its giving me
在快速响应我的 jquery ajax 请求时遇到了一些麻烦。实际发布工作正常，但无论我尝试什么，我似乎都无法从我可以使用的应用程序中实际获得数据响应。起初它只是不断地发布和挂起，就像一分钟后，它会响应一个警报，说“加载了 XML 文档”（不知道它来自哪里）——无论如何，现在它给了我
SyntaxError: Unexpected token ILLEGAL at parse (native) at IncomingMessage.
SyntaxError：在 IncomingMessage 解析（本机）时出现意外标记非法。
In my express App, I have:
在我的快递应用程序中，我有：
app.post('/save', function(req, res) {
console.log(req.body.objectData);
res.contentType('json');
res.send({ some: 'json' });
});
and in my jquery:
在我的 jquery 中：
$.ajax({
url: "/save",
type: "POST",
dataType: "json",
data: {objectData: someObject},
contentType: "application/json",
cache: false,
timeout: 5000,
complete: function() {
//called when complete
console.log('process complete');
},
success: function(data) {
console.log(data);
console.log('process sucess');
},
error: function() {
console.log('process error');
},
});
回答by Pastor Bones
You are not sending a valid JSON response but a String containing the word jsontherefore the JSON.parse()is failing on the client side. Try this:
您发送的不是有效的 JSON 响应，而是包含该词的字符串，json因此JSON.parse()在客户端失败。尝试这个：
app.post('/save', function(req, res) {
console.log(req.body.objectData);
res.contentType('json');
res.send({ some: JSON.stringify({response:'json'}) });
});
JavaScript Object Notationis a way to share data between applications in object format. However, you cannot send an object over an HTTP request without first turning it into a string and sending it as a single variable. The functions JSON.parse()and JSON.stringify()do this for us.
JavaScript Object Notation是一种以对象格式在应用程序之间共享数据的方法。但是，如果不先将对象转换为字符串并将其作为单个变量发送，则无法通过 HTTP 请求发送对象。函数JSON.parse()并JSON.stringify()为我们执行此操作。
回答by CLO
Pastor Bones' comment was particularly important to me, as I was using $.ajax to post to a Node server. My relevant portion of code ended up like this:
Pastor Bones 的评论对我来说特别重要，因为我使用 $.ajax 发布到 Node 服务器。我的相关代码部分最终是这样的：
// Incoming parameter "teams" is an array of objects
function saveTeams(teams) {
var xhr;
var data = JSON.stringify({ teams: teams });
xhr = $.ajax({
type: "POST",
url: "http://localhost:8000/saveteam",
contentType: "application/json",
data: data,
headers: {
Authorization: "..."
}
});
return xhr;
}
Note that the contentType header is relevant for the parsing to work.
请注意， contentType 标头与解析工作相关。
On the node server side, I can process the payload like this:
在节点服务器端，我可以像这样处理有效负载：
saveTeams: function (req, res, next) {
var teams = req.body.teams;
if (teams.length > 0) {
console.log("Teams to be added:");
for (var i = 0; i < teams.length; i++) {
console.log(teams[i]);
// ...
}
}
// ...
}
回答by Montana123
Since you are using express,
由于您使用的是快递，
res.contentType('json');
should be:
应该：
res.type('json');
but setting the type is not required since it is done automatically for you.
但是不需要设置类型，因为它会自动为您完成。
See the express api docs on res.type.
Also note that, for express, res.send({blah:"gee"});automatically converts json objects using JSON.stringify internally. After clicking the above link, click on res.sendand, while you are at it, res.jsonwhich saves a little processor overhead when you know you are sending JSON. Note that if you send JSON, the type is automatically set to JSON.
另请注意，对于 express，在res.send({blah:"gee"});内部使用 JSON.stringify 自动转换 json 对象。点击上面的链接后，点击res.sendand，当你在它的时候，res.json当你知道你正在发送 JSON 时，它会节省一点处理器开销。请注意，如果您发送 JSON，则类型会自动设置为 JSON。
Always best to look at the source! Note that res.send calls this.json when it detects JSON, and that res.json calls this.send (yeah seems like a loop but it all works out).
最好还是看源码！请注意， res.send 在检测到 JSON 时调用 this.json，而 res.json 调用 this.send（是的，看起来像一个循环，但一切正常）。
