I've got a node.js-based webserver running at home and i'm trying to implement a login form.
So basically I need to access POSTed data (login/password). I found this :
How do you extract POST data in Node.js?
(req.on('data'...) & req.on('end'...))
But i need to do this asynchronously, can someone tell me how to do that ?
(I need this code to be blocking, not non-blocking)
EDIT: All my code is available on Github :
https://github.com/Fointard/NodeJs/tree/authentication
The problem lies here : https://github.com/Fointard/NodeJs/blob/authentication/js/reqHandlers/auth.js Lines 98 and 104, i'm relying on 'data' and 'end' envents but i'd like to do that asychronously so that checkID() (line 95) is able to return true or false.
You can't. HTTP Requests are I/O operations and will always be resolved asychronously. Your checkID function will never return a value. You need to add a second parameter (usually called callback) that will be called with true or false.
function checkID(req, callback) {
var body = '';
req.on('data', function (data) {
body += data;
if (body.length > 1e6)
req.connection.destroy();
});
req.on('end', function () {
var post = qs.parse(body);
if ('loginInputLogin' in post && 'loginInputPassword' in post) {
console.log('login : '+post['loginInputLogin']);
console.log('password : '+post['loginInputPassword']);
}
if (post['loginInputLogin'] === 'fointard' && post['loginInputPassword'] === 'f01n') {
console.log('ID confirmed');
callback(true);
}
callback(false);
});
}
And use it like so:
checkID(yourRequest, function(success) {
if(success) {
//login successfull
} else {
//login failed
}
})
Related
I am using Express in Nodejs in order to make a GET Call. As a response, I get the value that I need, but when I return the value from my function to the main I get undefined.
function getInfo()
{
var oauth = getoAuth();
request.get({
url:'myurl',
oauth:oauth,
qs:null,
json:true
},
function (e, r, data) {
body.data = data;
body.emit('update');
});
body.on('update', function () {
console.log(body.data.issues[0].key);
return (body.data.issues[0].key);
});
}
This key is what I need. When I print it in the console I get the correct value, but it doesn't return anything, because it is an async call. How can I return the value? Can I somehow wait for the value using express? I saw on stackoverflow that some people used this body.on('update'... solution, but it didn't work for me. It still saves nothing to a variable.
EDIT-> the response:
TESTING: undefined
THEKEY1
Saving the value at:
var myid= geInfo();
try this way :
function getInfo()
{
var oauth = getoAuth();
request.get({ url:'myurl', oauth:oauth, qs:null, json:true},
function (error, response, body) {
if(!error && response && response.statusCode==200){
console.log(body);
return body.data.issues[0].key;
}else{
return null;
}
});
}
I have a post method, whose request input is a list of newLink objects (newLink with attributes linkUrl and status)
I am using async.map for iterating over my URLs to check if the links are active or not.
newLinks contains links like {www.google.com,www.nourl.com,www.xyz.com} I am expecting like after all the request are processed and setting corresponding status as true or false, I want this to send using res.send(newLinks)
But the console is giving the below results: "www.google.com is up", then calling res.send(), then executing "www.nourl.com is up" and "www.xyz.com is up"
So basically here, after the first url request , my code below is executing the function outside the async loop. I thought async will only allow the next piece of code to execute only after all the urls are validated.
app.post('/myposturl', function(req , res){
var request = require('request');
let linkDetails= req.body.linkDetails;
var i = 0;
async.map(linkDetails, function(newLink, callback) {
var Url = "url";
var url = newLink.linkUrl;
var proxiedRequest = request.defaults({'proxy': Url});
proxiedRequest(url , function (error, response, body) {
if(error){
console.log('Err: '+ error);
}
if (!error) {
if(response.statusCode == 200 || response.statusCode == 201 ||
response.statusCode == 202){
console.log(url + ' is up!!');
newLink.isActive = true;
}
if(response.statusCode == 301 || response.statusCode == 302){
console.log(url + ' is redirecting us!!');
return false;
}
}
});
callback();
} , function(err, linkDetails) {
res.send(linkDetails);
});
//tried res.send here as well.
});
}
The callback of async.map should invoke inside proxiedRequest. What your code is doing now: invoke callback immediately before the proxiedRequest finished. Also return false; does not work in asynchronous function. You should return the new status like this callback(null, newLink). After all the request are processed, the newLinkDetails will be the array of all newLink.
Note, that since this function applies the iteratee to each item in parallel, there is no guarantee that the iteratee functions will complete in order.
If you need to keep the order, user mapSeries insted.
Please read the doc of async.map for more. Hope it helps.
app.post('/myposturl', function(req , res){
//other codes
async.map(linkDetails, function(newLink, callback) {
//other codes
proxiedRequest(url , function (error, response, body) {
if(error){
console.log('Err: '+ error);
callback(error);
//^ ^ ^ ^ ^
// Validation failed, return from here
}
else {
//some validation & set newLink.isActive
callback(null, newLink);
// ^ ^ ^ ^ ^
//return newLink status by invoking the callback
}
});
}, function(err, newLinkDetails) {
//err = if any Validation failed
// now all the request are processed,newLinkDetails is array of all newLink's
res.send(newLinkDetails);
});
});
Usually when using async.js, I follow these two principles:
Always call the callback at least AND at most once during your async function.
Call the callback only when the async function is complete OR if an error has occurred. If the latter occurs, call the callback passing the error AND stop further execution of the async function e.g. return callback(error)
I would revise your code as below:
var request = require('request');
app.post('/myposturl', function (req , res) {
async.mapSeries(req.body.linkDetails || [], function(newLink, callback) {
var Url = "url";
var proxiedRequest = request.defaults({ 'proxy': Url });
proxiedRequest(newLink.linkUrl, function (err, response, body) {
if (err)
return callback(err);
// I'm assuming you don't want to stop checking the links for bad status codes
if ([301, 302].indexOf(response.statusCode) > -1){
return callback(null, url + ' is redirecting us!!');
if ([200, 201, 202].indexOf(response.statusCode) == -1) {
return callback(null, url + ' came back with ' + response.statusCode);
console.log(url + ' is up!!');
newLink.isActive = true;
callback(null, newLink);
});
}, function (err, linkDetails) {
// when all links get checked, it will come down here
// or if an error occurs during the iteration, it will come down here
console.log(err, linkdetails);
res.send(linkDetails);
});
});
If you only want to get back active links, you may also want to check out async.filterSeries(). Here the callback would need to be passed a boolean in its second argument.
I am using Facebook Graph NodeJS API to fetch user_posts. The response has pagination and therefore I need to loop over the response to fetch all the posts. I am using following route to fetch facebook posts and I am looping over pagination using get_user_statuses function:
var posts = "";
function get_user_statuses(response_posts, res) {
var link_regex = /https?:\/\/(?:www\.|(?!www))[^\s\.]+\.[^\s]{2,}|www\.[^\s]+\.[^\s]{2,}/g;
var isNextPageAvailable = true;
if ("paging" in response_posts) {
var nextPage = response_posts.paging.next;
isNextPageAvailable = true;
} else {
isNextPageAvailable = false;
}
for (var i = 0; i < response_posts.data.length; i++) {
var post = response_posts.data[i].message + " ";
if ("message" in response_posts.data[i]) {
posts += post.replace(link_regex, "");
}
}
if (nextPage !== undefined) {
request(nextPage, function (error, response, body) {
if (!error && response.statusCode === 200) {
get_user_statuses(JSON.parse(body));
} else {
console.log(error);
}
});
}
if (!isNextPageAvailable){
//Sending posts to facebook Modal
console.log(posts);
res.send(JSON.stringify({posts: posts})); //res is not defined here
}
}
router.post('/fbData', function (req, response, next) {
FB.setAccessToken(req.body.access_token);
FB.api('/me?fields=posts&posts.limit=1000', function (res) {
if (!res || res.error) {
if (!res) {
response.send(JSON.stringify({error: 'An error occurred. Please try again.'}))
}
response.send(JSON.stringify({error: response.error}));
return;
}
get_user_statuses(res.posts, response); //Passing response object here
});
});
The issue is that response object passed from express route is not defined in get_user_statuses function. Now I have two question:
Why is response object is not defined?
Is there better approach to achieve this arrangement?
res is not defined because you forgot to pass it in internal call. Change get_user_statuses(JSON.parse(body)); to get_user_statuses(JSON.parse(body), res); and it should work
I solved my problem. I needed to create a function with a callback. In case anyone else is stuck at this kind of issue, this post helped me resolve it:
[How to recurse asynchronously over API callbacks in node.js?
I have var movieRecommendation which is being populated from data coming from Mongo DB. Issue is Mongoose Movie.findOne() call is asycn call which is not allowing me to get my final populated movieRecommendation which I need to send back as response.
exports.getRecommendation=function(req,res){
var movieRecommendation = [];
var id=req.params.id;
console.log('----- Get User Recommendation - ' + id);
var url = 'http://52.8.48.113:8080/recommender-server/recommender/v1/recommendations/'+id+'.do';
//make http get request
request({
url: url,
json: true
}, function (error, response, recommendations) {
// res.json(recommendations);
if (!error && response.statusCode === 200) {
recommendations.forEach(function(entry) {
**Movie.findOne({'id':parseInt(entry.itemId)},function(err, movieData){**
entry.movie = movieData;
movieRecommendation.push(entry);
//console.log('rec', movieRecommendation);
console.log(movieRecommendation.length);
});
});
}
console.log("====Final========"+movieRecommendation.length);
//Output = 0
});
res.json(movieRecommendation); // Here movieRecommendation is coming as black Array
};
Please let me know how I can get finally populated movieRecommendation var at end to make it available for response.
For this type of issues we can use Async library. To populate the data finally once all the operations done, we can use async.each collection from Async Library.
For example:
NOTE:Install Async by this command
npm install async to use async library
var async = require("async");
var recomenmendations = [{"data2" : "value2"} , {"data1" : "value2"}, {"data3" : "value3"}, {"data4" : "value4"} ]
var movieRecommendation = [];
async.each(recomenmendations,
function(recomenmendationItem, callback){
console.log("Here you can query the required data using current recomenmendations ITEM");
console.log(recomenmendationItem);
callback();
// Movie.find({'id':parseInt(recomenmendationItem.itemId)},function(err, movieData){
// recomenmendationItem.movie = movieData;
// movieRecommendation.push(entry);
// callback();
// });
},
function(err){
console.log("here you can send your resopnse");
console.log("This section will be executed once all the recomenmendations are processed");
//res.json(movieRecommendation)
}
);
You can query the mongoDB as shown with comment section. You should use callback() once all the operations performed for an iteration.
As I mentioned in one of my comments, use the callback passed to the iterator function and call it inside the Movie.findOne() callback. That way, async.each will know when each step has finished:
async.each(recomendations, function (recomendationItem, callback) {
Movie.findOne({'id':parseInt(entry.itemId)},function(err, movieData){
if (err) return callback(err); // if you have an error on you search, just pass it to the iterator callback
recommendationItem.movie = movieData;
movieRecommendation.push(recommendationItem);
callback();
});
}, function (error) {
if (error) return res.json ({ error: error }); // you should also check if an error ocurred
res.json(movieRecomendation);
});
Just to point out: you can also use async.eachSeries, that will just call the next step of your iteration when the previous one has returned (if that matters to you, but I think it's not your case though) and it has the same signature.
#Vivek Panday replace the following code inside your exports.getRecommendation function to get your expected output. We don't need to use the count variable if we use the callback function. And an important thing is we have to use callback(); once all the process done. I think you have not used callback function properly in The example you have worked out. Use the following code If there is any issue please let me know.
var async = require('async');
var request = require("request");
var movieRecommendation = [];
var id=req.params.id;
console.log('----- Get User Recommendation - ' + id);
var url = 'http://52.8.48.113:8080/recommender-server/recommender/v1/recommendations/'+id+'.do';
//make http get request
request({
url: url,
json: true
}, function (error, response, recommendations) {
if (!error && response.statusCode === 200) {
console.log('recommendation lenght '+ recommendations.length);
async.each(recommendations,
function(recommendationItem, callback){
Movie.findOne({'id':parseInt(recommendationItem.itemId)},function(err, movieData){
recommendationItem.movie = movieData;
movieRecommendation.push(recommendationItem);
//you have to use callback(); once all your process is done
callback();
});
},
function(err){
//you should use this function, this will be execute once all the process done
console.log(movieRecommendation);
console.log("finally callback");
res.json(movieRecommendation);
}
);
}
});
I have tried as per given suggestion above ..
var async = require("async");
var recomenmendations = [{"data2" : "value2"} , {"data1" : "value2"}, {"data3" : "value3"}, {"data4" : "value4"} ]
var movieRecommendation = [];
async.each(recomenmendations,
function(recomenmendationItem, callback){
console.log("Here you can query the required data using current recomenmendations ITEM");
console.log(recomenmendationItem);
// Movie.find({'id':parseInt(recomenmendationItem.itemId)},function(err, movieData){
recomenmendationItem.movie = movieData;
movieRecommendation.push(entry);
console.log("any data"); // line y
});
callback();
},
function(err){
console.log("here you can send your resopnse"); // line x
console.log("This section will be executed once all the
recomenmendations are processed");
//res.json(movieRecommendation)
}
);
But still face same issue line x is printing before line y ,which is making again same issue.
However I have tried something given below and achieved expected result .
exports.getRecommendation=function(req,res){
var movieRecommendation = [];
var id=req.params.id;
console.log('----- Get User Recommendation - ' + id);
var url = 'http://52.8.48.113:8080/recommender-server/recommender/v1/recommendations/'+id+'.do';
//make http get request
request({
url: url,
json: true
}, function (error, response, recommendations) {
// res.json(recommendations);
if (!error && response.statusCode === 200) {
console.log('recommendation lenght '+ recommendations.length);
// recommendations.forEach(function(entry) {
var count=0;
async.each(recommendations,function(recommendationItem){
// console.log(recommendationItem);
Movie.findOne({'id':parseInt(recommendationItem.itemId)},function(err, movieData){
recommendationItem.movie = movieData;
movieRecommendation.push(recommendationItem);
count ++;
console.log('final res length : ' + movieRecommendation.length);
console.log('final res length count : ' + count +' and item recomm lenght ' + recommendations.length );
if(count === recommendations.length){
console.log(' =====Final=====> here you can send your response =========' + movieRecommendation.length);
res.json(movieRecommendation);
}
});
// callback();
});
}
});
};
Still I am open for any feedback and suggestions.
Ok, lets say I have two Models. Contract and CommLog. Both work find independently but I need many CommLog to relate to each Contract.
In the ContractSchema trying async
ContractSchema.methods.getCommLog = function getCommLog(){
var log = false;
async.parallel([
function(){
CommLog.find({commType:'contract',parent:this._id},function(err,comms){
log = comms;
});
}],
function(){return log;});
};
Where I am trying to use it
router.get('/:code', function(req, res, next) {
Contract.findOne({accessCode:req.params.code},function(err,contract){
if(err)
res.send(err);
var data;
if(contract != null){
var comms = contract.getCommLog();
data = {error:false,data:contract,commlog:comms}
}else{
data = {error:true,message:"No Contract"}
}
res.json(data);
});
});
Where it shows var comms = contract.getCommLog(); It is never returning anything because the getCommLog() is not executing async...
I think its my misunderstanding of mongoose querying, so if you understand what I am trying to accomplish, please let me know what I am doing wrong. I have tried without async which would always return false.
The find call can return all matching results with one query, so I don't think you need async here. The reason it is not populating correctly when you call res.json(data) is because you are not waiting for the method call to finish before you fire off your server response. You would be better off nesting an additional CommLogs.find call within the Contract.find call, and only sending your response once that finishes.
//pseudo code:
Contract.find({}, function(err, contract) {
if(err || !contract) {
//return error response
}
else {
CommLogs.find({contract: contract._id}, function(err, commlogs) {
if(err || !commlogs) {
//return error response 2
}
else {
res.json({errors: false, contract: contract, commlogs: commlogs});
}
});
}
}