I kept having this error when i deploy my app onto meteor cloud server.
Meteor code must always run within a Fiber
at _.extend.get (app/packages/meteor/dynamics_nodejs.js:14:13)
at _.extend.apply (app/packages/livedata/livedata_server.js:1268:57)
at _.extend.call (app/packages/livedata/livedata_server.js:1229:17)
at Meteor.startup.Meteor.methods.streamTwit (app/server/server.js:50:24)
however, I have already wrapped within Fibers
streamTwit: function (twit){
var userid = '1527228696';
twit.stream(
'statuses/filter',
{ follow: userid},
function(stream) {
stream.on('data', function(tweet) {
Fiber(function(){
if(tweet.user.id_str === userid)
{
Meteor.call('addQn', tweet);
}
}).run();
console.log(tweet);
console.log('---------------------------------------------------------');
console.log(tweet.user.screen_name);
console.log(tweet.user.name);
console.log(tweet.text);
});
}
);
}
I don't know what's the reason but someone suggested that i should wrap it with Meteor.bindEnvironment instead. Hence, I did this:
streamTwit: function (twit){
this.unblock(); // this doesn't seem to work
console.log('... ... trackTweets');
var _this = this;
var userid = '1527228696';
twit.stream(
'statuses/filter',
{ follow: userid},
function(stream) {
stream.on('data', function(tweet) {
Meteor.bindEnvironment(function () {
if(tweet.user.id_str === userid)
{
Meteor.call('addQn', tweet);
}
}, function(e) {
Meteor._debug("Exception from connection close callback:", e);
});
console.log(tweet);
console.log('---------------------------------------------------------');
console.log(tweet.user.screen_name);
console.log(tweet.user.name);
console.log(tweet.text);
});
}
);
}
//add question method
addQn:function(tweet){
questionDB.insert({'tweet': tweet, 'date': new Date()});
}
but now it doesn't even work. I realise that this only happened when I tried to insert some data into mongodb.
May I know what is the problem with my code? Thanks!
All these codes were written in app/server/server.js
You shouldn't need to use Meteor.call on the server side. That is for client-side code only. Just call addQn directly or better yet, inline it since it's just one line of code.
Related
I have been on this for a while. The problem with is is that this line of code never get executed let userSchool = SchoolDb.findOne({slug: Session.get('ReceivedSlug')}); When I logged on the console I see the the slug is dynamic as it is suppose to be pull the record from the db. What am I to do right?
The oncreated template
Template.view.onCreated(function () {
Session.set('ReceivedSlug', FlowRouter.getParam('myslug'));
this.autorun(function () {
Meteor.subscribe('SingleSchool', Session.get('ReceivedSlug'));
});
});
The helper function
singleSchool: function () {
if (Meteor.userId()) {
console.log('reactive this ---- ' +Session.get('ReceivedSlug'));
let userSchool = SchoolDb.findOne({slug: Session.get('ReceivedSlug')});
if (!userSchool) {
Bert.alert('School not present', 'danger', 'growl-top-right');
} else {
console.log('school name ----' +userSchool.slug);
return userSchool;
}
}
},
Can you please check whether the subscription has fetched data. Also console out inside publish that whether data gets published when slug changed.
Use below code to check if subscription is working
Meteor.subscribe('SingleSchool', Session.get('ReceivedSlug'), {
onReady: function(){
console.log(SchoolDb.find({}).fetch());
}
});
When user refresh a certain page, I want to set some initial values from the mongoDB database.
I tried using the onRendered method, which in the documentation states will run when the template that it is run on is inserted into the DOM. However, the database is not available at that instance?
When I try to access the database from the function:
Template.scienceMC.onRendered(function() {
var currentRad = radiationCollection.find().fetch()[0].rad;
}
I get the following error messages:
Exception from Tracker afterFlush function:
TypeError: Cannot read property 'rad' of undefined
However, when I run the line radiationCollection.find().fetch()[0].rad; in the console I can access the value?
How can I make sure that the copy of the mongoDB is available?
The best way for me was to use the waitOn function in the router. Thanks to #David Weldon for the tip.
Router.route('/templateName', {
waitOn: function () {
return Meteor.subscribe('collectionName');
},
action: function () {
// render all templates and regions for this route
this.render();
}
});
You need to setup a proper publication (it seems you did) and subscribe in the route parameters. If you want to make sure that you effectively have your data in the onRendered function, you need to add an extra step.
Here is an example of how to make it in your route definition:
this.templateController = RouteController.extend({
template: "YourTemplate",
action: function() {
if(this.isReady()) { this.render(); } else { this.render("yourTemplate"); this.render("loading");}
/*ACTION_FUNCTION*/
},
isReady: function() {
var subs = [
Meteor.subscribe("yoursubscription1"),
Meteor.subscribe("yoursubscription2")
];
var ready = true;
_.each(subs, function(sub) {
if(!sub.ready())
ready = false;
});
return ready;
},
data: function() {
return {
params: this.params || {}, //if you have params
yourData: radiationCollection.find()
};
}
});
In this example you get,in the onRendered function, your data both using this.data.yourData or radiationCollection.find()
EDIT: as #David Weldon stated in comment, you could also use an easier alternative: waitOn
I can't see your collection, so I can't guarantee that rad is a key in your collection, that said I believe your problem is that you collection isn't available yet. As #David Weldon says, you need to guard or wait on your subscription to be available (remember it has to load).
What I do in ironrouter is this:
data:function(){
var currentRad = radiationCollection.find().fetch()[0].rad;
if (typeof currentRad != 'undefined') {
// if typeof currentRad is not undefined
return currentRad;
}
}
I'm using the Node.JS driver for MongoDB, and I'd like to perform a synchronous query, like such:
function getAThing()
{
var db = new mongo.Db("mydatabase", server, {});
db.open(function(err, db)
{
db.authenticate("myuser", "mypassword", function(err, success)
{
if (success)
{
db.collection("Things", function(err, collection)
{
collection.findOne({ name : "bob"}, function(err, thing)
{
return thing;
});
});
}
});
});
}
The problem is, db.open is an asychronous call (it doesn't block), so the getAThing returns "undefined" and I want it to return the results of the query. I'm sure I could some sort of blocking mechanism, but I'd like to know the right way to do something like this.
ES 6 (Node 8+)
You can utilize async/await
await operator pauses the execution of asynchronous function until the Promise is resolved and returns the value.
This way your code will work in synchronous way:
const query = MySchema.findOne({ name: /tester/gi });
const userData = await query.exec();
console.log(userData)
Older Solution - June 2013 ;)
Now the Mongo Sync is available, this is the right way to make a synchronous MongoDB query in Node.js.
I am using this for the same. You can just write sync method like below:
var Server = require("mongo-sync").Server;
var server = new Server('127.0.0.1');
var result = server.db("testdb").getCollection("testCollection").find().toArray();
console.log(result);
Note: Its dependent on the node-fiber and some issues are there with it on windows 8.
Happy coding :)
There's no way to make this synchronous w/o some sort of terrible hack. The right way is to have getAThing accept a callback function as a parameter and then call that function once thing is available.
function getAThing(callback)
{
var db = new mongo.Db("mydatabase", server, {});
db.open(function(err, db)
{
db.authenticate("myuser", "mypassword", function(err, success)
{
if (success)
{
db.collection("Things", function(err, collection)
{
collection.findOne({ name : "bob"}, function(err, thing)
{
db.close();
callback(err, thing);
});
});
}
});
});
}
Node 7.6+ Update
async/await now provides a way of coding in a synchronous style when using asynchronous APIs that return promises (like the native MongoDB driver does).
Using this approach, the above method can be written as:
async function getAThing() {
let db = await mongodb.MongoClient.connect('mongodb://server/mydatabase');
if (await db.authenticate("myuser", "mypassword")) {
let thing = await db.collection("Things").findOne({ name: "bob" });
await db.close();
return thing;
}
}
Which you can then call from another async function as let thing = await getAThing();.
However, it's worth noting that MongoClient provides a connection pool, so you shouldn't be opening and closing it within this method. Instead, call MongoClient.connect during your app startup and then simplify your method to:
async function getAThing() {
return db.collection("Things").findOne({ name: "bob" });
}
Note that we don't call await within the method, instead directly returning the promise that's returned by findOne.
While it's not strictly synchronous, a pattern I've repeatedly adopted and found very useful is to use co and promisify yield on asynchronous functions. For mongo, you could rewrite the above:
var query = co( function* () {
var db = new mongo.Db("mydatabase", server, {});
db = promisify.object( db );
db = yield db.open();
yield db.authenticate("myuser", "mypassword");
var collection = yield db.collection("Things");
return yield collection.findOne( { name : "bob"} );
});
query.then( result => {
} ).catch( err => {
} );
This means:
You can write "synchronous"-like code with any asynchronous library
Errors are thrown from the callbacks, meaning you don't need the success check
You can pass the result as a promise to any other piece of code
I'm new to AngularJS and to JS testing in general and I'm having trouble wrapping my mind around how to go about testing this rather simple service. I've tried using $httpBackend with 'when' and 'expect' GET in variations configurations, to no avail. The test should verify that 1) data is returned via the deferred.resolve and 2) no data is returned via the deferred.reject. If someone could point me in the right direction i'd be quite grateful. Thanks!
btw: I'm using Jasmine + Testacular
.service('myService', function($http, $q) {
return {
getMyData: function() {
var deferred = $q.defer();
$http.get('/foo/bar.do').success(function(data) {
deferred.resolve(data);
}).error(function(){
deferred.reject();
});
return deferred.promise;
}
}
})
I had kind of the same problem testing a service with $http and $q.
Here is one of my test which passes:
it('should issue a GET request to /foo/bar.do', inject(function ($httpBackend) {
$httpBackend.when('GET', '/foo/bar.do').respond('success');
var finalResult = '';
var result = myService.getMyData();
result.then(function(data) {
finalResult = data;
}, function() {
console.log('error');
});
$httpBackend.flush();
expect(finalResult).toBe('success');
}));
I've tried to understand this post regarding this concept, however, I'm failing to get it. I have the following simple setup:
/server/test.js
Meteor.methods({
abc: function() {
var result = {};
result.foo = "Hello ";
result.bar = "World!";
return result;
}
});
/client/myapp.js
var q = Meteor.call('abc');
console.log(q);
This structure returns to the console undefined.
If I change the myapp.js file to:
Meteor.call('abc', function(err, data) {
!err ? console.log(data) : console.log(err);
}
I receive the Object in my console.
Ideally this is what I'd like to be able to do, but it doesn't work, stating in the console: Cannot read property 'greeting' of undefined
/client/myapp.js
var q = Meteor.call('abc');
Template.hello.greeting = function() {
return q.foo;
}
Any help in passing the data from the server object into the template would be greatly appreciated. I'm still learning JavaScript & Meteor.
Thanks!
From the Meteor.call documentation:
On the client, if you do not pass a callback and you are not inside a stub, call will return undefined, and you will have no way to get the return value of the method. That is because the client doesn't have fibers, so there is not actually any way it can block on the remote execution of a method.
So, you'll want to do it like this:
Meteor.call('abc', function(err, data) {
if (err)
console.log(err);
Session.set('q', data);
});
Template.hello.greeting = function() {
return Session.get('q').foo;
};
This will reactively update the template once the data is available.
This happens because Npm.require has Async behavior. That's the reason that you have to write a callback for Meteor.call.
But there is a solution, just use install(mrt add npm) and you'll get a function named Meteor.sync(//...) with this you can do both games: sync and async in your Meteor.call().
Reference: http://www.sitepoint.com/create-a-meteor-app-using-npm-module/
You can get the return value of a Meteor method for use in a template by using a reactive variable. Check out the working demonstration on Meteorpad
I went for a ghetto solution. But, it works for me, which is what matters, to me. Below is my code, which, in concept, I think, solves OP's problem.
In the client's main.js:
Meteor.setInterval(function() {
confirmLogin();
}, 5000);
This runs the confirmLogin() function every five seconds.
The confirmLogin function (in the client's main.js):
function confirmLogin() {
Meteor.call('loggedIn', function (error, result) {
Session.set("loggedIn", result);
});
}
The loggedIn method (in the server's main.js):
loggedIn: function () {
var toReturn = false;
var userDetails = Meteor.user();
if (typeof userDetails["services"] !== "undefined") {
if (typeof userDetails["services"]["facebook"] != "undefined") {
toReturn = true;
}
}
return toReturn;
},
The relevant helper:
loggedIn: function () {
return Session.get("loggedIn");
}