I'm running into a scenario where my meteor server call is posting to a remote URL and then returning the result. However, my meteor client is expecting a result right away and its receiving an empty string (the default return).
What is the correct way of implementing this?
Meteor.methods({
run: function(options){
return HTTP.post(apiUrl, {
params:
{
"headers": headers
}
},
function (error, result)
{
if (error)
{
console.log("error: " + error);
}
else
{
console.log("result: " + JSON.stringify(result));
console.log(result.content);
}
})
});
on my client
Meteor.call('run', '1', function(err,response) {
if(err) {
console.log(err);
return;
}else{
r = response;
console.log(JSON.stringify(r));
FileSystem.update({ _id: fileid }, { $set: {taskid:taskid} }, function (e, t) {
if (e) {
}else{
}
});
}
});
I'm expecting on the client side that it waits for the full result to come in which contains the desired data to save to data base (taskid).
You are calling HTTP.post asynchronously. Just remove the callback function and it becomes synchronous, i.e., you will get a return value that contains the result of the call:
Meteor.methods({
run: function(options){
return HTTP.post(apiUrl, {
params:
{
"headers": headers
}
});
});
});
Related
I am playing with elasticsearch.js from the browser. I would like to ping elasticsearch, wait for the request to complete and then return the result of the connection. But right now it is happening asynchronously, and returning undefined even when the connection is ok. I have code like this:
var connectionOK = false;
function createElasticsearchClient(hostAddress) {
var client = new $.es.Client({
hosts: hostAddress
});
return client;
}
function checkElasticsearchConnection(client) {
$.when(pingElasticsearch(client)).done(function () {
return connectionOK;
});
}
function pingElasticsearch(client) {
console.log("ELASTICSEARCH: Trying to ping es");
client.ping({
requestTimeout: 30000,
// undocumented params are appended to the query string
hello: "elasticsearch"
}, function (error) {
if (error) {
console.error('ELASTICSEARCH: Cluster is down!');
connectionOK = false;
console.log("INSIDE: " + connectionOK);
} else {
console.log('ELASTICSEARCH: OK');
connectionOK = true;
console.log("INSIDE: " + connectionOK);
}
});
}
and how it is used:
var esClient = createElasticsearchClient("exampleserver.com:9200");
var esCanConnect = (checkElasticsearchConnection(esClient));
You're mixing asynchronous functions with synchronous functions. You could go with this approach instead:
function createElasticsearchClient(hostAddress, callback) {
var client = new $.es.Client({
hosts: hostAddress
});
return callback(client);
}
function pingElasticsearch(client, callback) {
console.log("ELASTICSEARCH: Trying to ping es");
client.ping({
requestTimeout: 30000,
// undocumented params are appended to the query string
hello: "elasticsearch"
}, function (error) {
if (error) {
return callback('ELASTICSEARCH: Cluster is down!');
} else {
return callback(null);
}
});
}
And then run
createElasticsearchClient("exampleserver.com:9200", function(esClient) {
pingElasticsearch(esClient, function(err) {
if (err) console.log(err);
else {
//Everything is ok
console.log('All good');
}
});
});
I would like to make http call synchronously using Q Promises, I have 100 students that I need for each of them to take some data from another platform and to do that I was trying via Q Promises but it does not seem like it is doing synchronously.
How do I make sure that another call is not being made once one is finished with parsing it's response and insertion into mongodb:
my code so far looks like this:
var startDate = new Date("February 20, 2016 00:00:00"); //Start from February
var from = new Date(startDate).getTime() / 1000;
startDate.setDate(startDate.getDate() + 30);
var to = new Date(startDate).getTime() / 1000;
iterateThruAllStudents(from, to);
function iterateThruAllStudents(from, to) {
Student.find({status: 'student'})
.populate('user')
.exec(function (err, students) {
if (err) {
throw err;
}
async.eachSeries(students, function iteratee(student, callback) {
if (student.worksnap.user != null) {
var worksnapOptions = {
hostname: 'worksnaps.com',
path: '/api/projects/' + project_id + '/time_entries.xml?user_ids=' + student.worksnap.user.user_id + '&from_timestamp=' + from + '&to_timestamp=' + to,
headers: {
'Authorization': 'Basic xxxx='
},
method: 'GET'
};
promisedRequest(worksnapOptions)
.then(function (response) { //callback invoked on deferred.resolve
parser.parseString(response, function (err, results) {
var json_string = JSON.stringify(results.time_entries);
var timeEntries = JSON.parse(json_string);
_.forEach(timeEntries, function (timeEntry) {
_.forEach(timeEntry, function (item) {
saveTimeEntry(item);
});
});
});
callback();
}, function (newsError) { //callback invoked on deferred.reject
console.log(newsError);
});
}
});
function saveTimeEntry(item) {
Student.findOne({
'worksnap.user.user_id': item.user_id[0]
})
.populate('user')
.exec(function (err, student) {
if (err) {
throw err;
}
student.timeEntries.push(item);
student.save(function (err) {
if (err) {
console.log(err);
} else {
console.log('item inserted...');
}
});
});
}
function promisedRequest(requestOptions) {
//create a deferred object from Q
process.env.NODE_TLS_REJECT_UNAUTHORIZED = "0";
var deferred = Q.defer();
var req = http.request(requestOptions, function (response) {
//set the response encoding to parse json string
response.setEncoding('utf8');
var responseData = '';
//append data to responseData variable on the 'data' event emission
response.on('data', function (data) {
responseData += data;
});
//listen to the 'end' event
response.on('end', function () {
//resolve the deferred object with the response
console.log('http call finished');
deferred.resolve(responseData);
});
});
//listen to the 'error' event
req.on('error', function (err) {
//if an error occurs reject the deferred
deferred.reject(err);
});
req.end();
//we are returning a promise object
//if we returned the deferred object
//deferred object reject and resolve could potentially be modified
//violating the expected behavior of this function
return deferred.promise;
}
Anyone could tell me what do I need to do to achieve such things?
Is it also possible so that I know when all of the http calls are finished and the insertion is done for all...
I would abandon your current approach and use the npm module request-promise.
https://www.npmjs.com/package/request-promise
It's very popular and mature.
rp('http://your/url1').then(function (response1) {
// response1 access here
return rp('http://your/url2')
}).then(function (response2) {
// response2 access here
return rp('http://your/url3')
}).then(function (response3) {
// response3 access here
}).catch(function (err) {
});
Now you just need to convert this to some kind of iteration for the 100 requests you want and the job will be done.
I am Learning Meteor and Javascript. I am using an npm package to get meta data of an url on the server side. This works fine. But I get undefined when passing that result back to client. Would appreciate some help.
Here is my code
if (Meteor.isClient) {
Meteor.call('getMetaData', "http://www.bbc.co.uk/news", function (err, data) {
if (err) {
console.log("error", err);
};
console.log("Meta data: " + data); //shows undefined
});
}
if (Meteor.isServer) {
Meteor.startup(function () {
var preview = Meteor.npmRequire('page-previewer');
Meteor.methods({
getMetaData: function (url) {
preview(url, function (err, data) {
if (!err) {
console.log(data); //Works fine
return data;
}
});
}
})
});
}
You need to convert the preview function to an synchronous function,using Future like this, this will make this function wait normal err,data callbacks into a synchronous function.
var Future = Npm.require('fibers/future'),
preview = Meteor.npmRequire('page-previewer');
Meteor.methods({
getMetaData: function(url) {
var f = new Future();
preview(url, function(err, data) {
if (!err) {
return f.return(data);
}
});
return f.wait();
}
});
Now this snippet should work
if (Meteor.isClient) {
Meteor.call('getMetaData', "http://www.bbc.co.uk/news", function (err, data) {
if (err) {
console.log("error", err);
}else{
console.log("Meta data: " + data); //shows undefined
}
});
};
try using else block to get the meta data. here's a solution of a similar problem .
https://forums.meteor.com/t/client-getting-undefined-for-server-method/6129/4?u=faysal
so basically you need to add only one extra line
else{ console.log('metadata '+ data);}
I'm 'modularizing' my application and I am using a Promise to pull data from my database inside my controller. After the data is back I want to deal with the response in another function:
Inside my controller i have:
var options = {
method: 'GET',
model: Event,
sort: {},
limit: {},
options: {}
};
database(options)
.then(handleResponse.ok)
.then(undefined, handleResponse.error);
And in the handleResponse file:
var response = {
ok: function(result, res) {
if (!result) {
return false;
}
response.json(result);
},
error: function (error) {
if (!error) {
return false;
}
console.log('Error: ' + error);
}
};
module.exports = response;
But the response.json is undefined. There is anyway that i can access the request and response inside the handleResponse file?
I write application by phonegap
Server Side I write by nodejs
exports.login = function(request, response) {
var keys = Object.keys(request.query);
request.body= JSON.parse(keys[1]);
Accounts.findOne({
name : request.body.name
}, function(err, docs) {
if (!docs) {
response.json('{"error": "user-not-found"}');
} else {
console.log("docs: ", docs);
Accounts.validatePassword(request.body.password, docs['hashedPass'], docs['salt'], function(error, res) {
if (error) {
response.json(error);
}
if (res) {
generateToken(request.body.name, request.body.device, function(res) {
if (res) {
response.json('{"token": "' + res + '"}');
} else {
response.json('{"error": "cant-create-token"}');
}
});
} else {
response.json('{"error": "invalid-password"}');
}
});
}
})
}
Phonegap: I write function to login
function LoginUser(info)
{
var varUrl=server+"/auth/login";
$.ajax({
url:varUrl,
type:"GET",
contentType:"application/json",
headers: {
Accept:"application/json",
"Access-Control-Allow-Origin": "*"
},
data:info,
dataType:"jsonp",
success:function(data)
{
console.log("HERE");
console.log(data);
},
error: function(err){
console.log(err);
}
});
}
and I request it will like this http://localhost:3000/auth/login?callback=jQuery161014894121675752103_1361459462241&{%22name%22:%22fdfdfd%22,%22password%22:%22fdfdfdfd%22}&_=1361459615743
and when I see in the response of tab network of developer of chrome is "{\"error\": \"user-not-found\"}"
but I can not catch this repsonse in function LoginUser(info) above
How to get it because in console it print error: function(err){
console.log(err);
}
I dont know why.
Can you help me.
On the server side you have to use callback and in the response of your
jsonp file you need to do:
jQuery161014894121675752103_1361459462241({"error": "user-not-found"})
Where the function name comes from the callback variable in your jsonp request.
Cause a jsonp request just "include" a script tag in your site, which can execute js (basically).