I have a problem with a jQuery Ajax request that does not respond when my NodeJS server crushes.
function postRequest(url, query, onComplete) {
$.post(url, query)
.done(function (response) {
onComplete(false, response);
})
.fail(function (xhr) {
onComplete(true, xhr.status);
});
}
postRequest('/noderoute', {id: 4}, function (error, res) {
if (!error) {
$('#content').html(res);
}
else {
alert(res);
}
});
If the server responds, all is good and well but if it crushes nothing happens. How can I solve this? Thank you.
Edit: Solved
I have been running my tests on a production build instead of my development files. Everything working fine now.
You are passing an incorrect xhr argument to your fail call.
.fail(xhr, function () {
should be
.fail(function (xhr) {
Related
I am trying to send/update data to mongoDB database via AAJAX call but the command is not reaching theere. I have tried debugging using alert in between the code but the command is not reaching there. Means AJAX call doesn't get executed.
Below is my AJAX POST request code:
var text = "Done";
var data = {
selectedValue: text
}
$ajax({
method: 'POST',
url: '/update-sources',
dataType: 'text/json',
data: data,
success: function(data){
console.log(data);
alert("Working!!")
}
});
And Below is the /update-sources route code:
router.post('/update-sources', function(req, res, next) {
console.log("/Update-Sources")
User.findOneAndUpdate({email: req.user.email}, {$set:{status:data.selectedValue}}, {new: true}, (err, doc) => {
if (err) {
console.log("Something wrong when updating data!");
}
else
{
res.render('taskswriter');
console.log(doc);
return "Great Working!";
}
});
});
What mistake I am doing?
Would be great if you shared browser's console output, but trying to execute attached client-side snippet, I got the following error:
VM219:7 Uncaught ReferenceError: $ajax is not defined
at <anonymous>:7:1
You've got a typo there - it should be $.ajax as you are accessing a function from within jQuery namespace (https://api.jquery.com/jQuery.ajax/)
I have a simple node Express app that has a service that makesa call to a node server. The node server makes a call to an AWS web service. The AWS simply lists any S3 buckets it's found and is an asynchronous call. The problem is I don't seem to be able to get the server code to "wait" for the AWS call to return with the JSON data and the function returns undefined.
I've read many, many articles on the web about this including promises, wait-for's etc. but I think I'm not understanding the way these work fully!
This is my first exposer to node and I would be grateful if somebody could point me in the right direction?
Here's some snippets of my code...apologies if it's a bit rough but I've chopped and changed things many times over!
Node Express;
var Httpreq = new XMLHttpRequest(); // a new request
Httpreq.open("GET","http://localhost:3000/listbuckets",false);
Httpreq.send(null);
console.log(Httpreq.responseText);
return Httpreq.responseText;
Node Server
app.get('/listbuckets', function (req, res) {
var bucketData = MyFunction(res,req);
console.log("bucketData: " + bucketData);
});
function MyFunction(res, req) {
var mydata;
var params = {};
res.send('Here are some more buckets!');
var request = s3.listBuckets();
// register a callback event handler
request.on('success', function(response) {
// log the successful data response
console.log(response.data);
mydata = response.data;
});
// send the request
request.
on('success', function(response) {
console.log("Success!");
}).
on('error', function(response) {
console.log("Error!");
}).
on('complete', function() {
console.log("Always!");
}).
send();
return mydata;
}
Use the latest Fetch API (https://developer.mozilla.org/en-US/docs/Web/API/Fetch_API) to make HTTP calls. It has built-in support with Promise.
fetch('http://localhost:3000/listbuckets').then(response => {
// do something with the response here
}).catch(error => {
// Error :(
})
I eventually got this working with;
const request = require('request');
request(url, function (error, response, body) {
if (!error && response.statusCode == 200) {
parseString(body, function (err, result) {
console.log(JSON.stringify(result));
});
// from within the callback, write data to response, essentially returning it.
res.send(body);
}
else {
// console.log(JSON.stringify(response));
}
})
I have an internally maintained npm package myNpmPackage which exports a function (for e.g. fnTestMicroSerConn ) as below:
const rp = require('request-promise-native')
exports.fnTestMicroSerConn = function () {
return new Promise(function(resolve, reject) {
var options = {
method: 'GET',
uri : "http://example.net",
resolveWithFullResponse: true,
}
rp(options)
.then(function (response) {
if (response.statusCode !== 200){
console.error("http not 200 but : ",response.statusCode)
resolve(false)
} else {
console.info("connected successfully : "+response.body)
resolve(response)
}
})
.catch(function (err) {
console.error("Error in establishing connectivity : ",err)
resolve(false)
})
})
}
I then need to call the above exported function from a Meteor method like so:
import { Meteor } from 'meteor/meteor';
import myNpmPackage from 'myNpmPackage';
Meteor.methods({
foo: function () {
myNpmPackage.fnTestMicroSerConn().then(function (response){
console.log(" My response: ",response.body);
return(response.body)
})
}
});
console.log(" My response: ",response.body); gets executed successfully and I can see the expected value in the server console log. So till here it's good.
However, now I want to pass the value of response.body to the client side. In short, when I do below on the client :
Meteor.call("foo", function (err, response) {
console.log("calling foo");
if(!err){
console.log("response : ",response);
} else {
console.log("err : ",err);
}
})
Unfortunately, currently I am getting undefined on the client for console.log("response : ",response);
Note: I am using the Meteor Promise package from here
Let me know if any more details are needed or any thing is unclear. I am very new to the Promise style of coding, hence, this can sound as a noob question.
Meteor methods called from clients by Meteor.call run synchronously to prevent clients from pending, even if a callback is supplied.
Your foo method does not wait for that promise inside. It runs past fnTestMicroSerConn() call without hesitation and ends up with no more statement to execute, returning undefined as a result. By the time the promise resolved and logged the expected message on the server console, the method had been exited.
To get resolved/rejected result of that promise, you can return the promise from the method to the caller, and the client would be able to respond to the promise.
Meteor.methods({
foo: function () {
return myNpmPackage.fnTestMicroSerConn();
}
});
Meteor.call("foo")
.then( response => console.log("My response: ", response.body) )
.catch( err => console.log("err : ",err) );
Meteor methods is powerful. The API documentation of methods contains much information and is worth mastery.
I have socket.emit call from client to server in response i want to have filename to the client that is not happening with below code not sure what is implemented wrong any idea, I do not see any error. How can i get response fro server using socket.emit ?
client.js
socket.emit('startRecording',function (response) {
console.log('start recording emit response',response);
});
server.js
socket.on('startRecording',function () {
var response;
logsRecording(function (filename) {
response = filename;
return response;
//socket.emit('filename',filename);
});
To acknowledge the message, your handler for the startRecording event needs to accept an acknowledgement callback as a parameter. You can then call that with your desired data. See Sending and getting data (acknowledgements)
socket.on('startRecording',function (socket, ackFn) {
var response;
logsRecording(function (filename) {
ackFn(filename);
});
});
Alternatively, you could add a listener for that filename event you have commented out, in the client.js:
socket.emit('startRecording');
socket.on('filename', function(filename) {
console.log('Filename received: ' + filename);
});
It might be helpful to run through Get Started: Chat application starting at the heading "Integrating Socket.IO" to get a more general understanding of Websockets.
Your server code should look like this:
socket.on('startRecording',function (callbackFn) {
var response;
logsRecording(function (filename) {
callbackFn(filename);
});
If you want to pass in data from your client:
socket.emit('startRecording', {someData: 'value'}, function (response) {
then server will be :
socket.on('startRecording',function (dataFromClient, callbackFn) {
Thank you for this helpfull hint
Here an 2020 "call" example call possible to use with moleculer microservices with four arguments:
The server responds in the callback function with two arguments err and res for the angular promise.
Angular 9 socket io
protected call(method: string, param?: any) {
try {
return new Promise((resolve, reject) => {
this.socket.emit("call", method, param, (err: any, res: unknown) => {
console.log(res);
if (err) { return reject(err); }
return resolve(res);
});
});
} catch (err) {
console.error(err);
}
}
Socket IO server response
socket.on('call', function(method, param, callbackFn){ // call method, param,
console.log(param);
switch (method) {
case "test":
console.log("test detected");
callbackFn(null , {name:"test",email:"test"});
break;
}
});
So im completely stumped and hope someone can help with the combination of Node JS Async and Request modules. I'm attempting to build a list of file to download which I pass to Async, as an array of object contain all the information I need to download and store said file. After tons of debugging I discovered that Request are not even making there way out and I cant figure out why.
async.each(missingFiles,
function (obj, cb) {
console.log(obj.url);
//var file = nfs.createWriteStream(obj.fullPath);
request(obj.url, function (error, response, body) {
if (!error && response.statusCode == 200) {
console.log(response)
}
cb();
})
},
function (err) {
if (err) {
console.log("Async failed");
}
}
);
I came across similar issues before. If you send response outside the async block, http request/response cycle ends before your async tasks complete. The fix is to have send response in the done() callback.
app.post("/download", function(req, res) {
async.eachSeries(missingFiles, function (obj, cb) {
...
//do your work here
cb()
}, function done() {
res.json({success: true});
});
}