Meteor insert into collection appears to work, but remains empty - asynchronous

I'm doing a simple insert into a meteor collection that appears work, but leaves the collection empty.
The collection is defined properly on the server:
Meteor.publish("comments", function () {
return Comments.find();
});
Subscribed to properly in the client.js:
Meteor.subscribe("commments");
And set up properly on the model.js:
Comments = new Meteor.Collection("comments");
The insert code is as follows:
Meteor.methods({
addComment: function (options) {
check(options.post_id, String);
check(options.comment, NonEmptyString);
if (! this.userId)
throw new Meteor.Error(403, "You must be logged in to comment.");
if (options.comment.length > 1000)
throw new Meteor.Error(413, "Comment is too long");
var post = Posts.findOne(options.post_id);
if (! post)
throw new Meteor.Error(404, "No such post");
// add new comment
var timestamp = (new Date()).getTime();
console.log('Comment: ' + options.comment);
console.log('Post: ' + options.post_id);
console.log('UserId: ' + this.userId);
var saved = Comments.insert({
owner: this.userId,
post_id: options.post_id,
timestamp: timestamp,
text: options.comment});
console.log('Saved: ' + saved);
}
});
Once the insert is called, the console prints out the following:
Comment: Something
Post: xRjqaBBEMa6qjGnDm
UserId: SCz9e6zrpcQrKXYWX
Saved: FCxww9GsrDsjFQAGF
> Comments.find().count()
0
I have inserts into several other collections that work just fine (Posts being one of them as you can see the post ID in the code). In the docs ist said that if the insert errors out it will print to the console, but as you can see it appears to be working, yet is actually empty.
Thanks.
UPDATE: I did find that the data is being put into the database, but for some reason is not showing up. I'm not sure why the data is not being published properly since there are no filters on the find().

I'm not sure exactly what's wrong, but there's a few things to check here.
• First, this:
Meteor.publish("comments", function () {
return Comments.find();
});
directs the server to publish the Collection, but doesn't actually establish the collection server side.
You should have Comments = new Meteor.Collection("comments"); available on both the client and the server. I tend to put in a file called model.js like the examples tend to do.
• Second possibility, you don't have a subscribe function shown above, such as Meteor.subscribe("comments"); If you don't have a subscribe function, your client isn't going to know about it, even though it does exist in the collection.
You can test this theory by typing meteor mongo in the shell (with your Meteor app running), and db.comments.find() to see if your comments are actually in the database but not subscribed to.

Verify you do not have an error in your client code. With Meteor.call, if you do not initialize a variable you can have an error condition that will block reactive updating in your templates but continue to write fine to your console just before hand.
I've made that mistake which I talk about here:
http://doctormehmet.blogspot.com/2013/07/revoltdc-hackathon-20130622-iteration-3.html
Specifically I had something like
Template.mytemplate.helpers({
somevar: function({
if (some_session_var_set_by_a_call.party){
//do something
}
}
Now the somevar function gets called on render, before the Meteor.call returns. Therefore the variable some_session_var_set_by_a_call isn't set yet. The whole thing stops client side on the undefined error.

Related

Meteor: what is the right way to add custom settings object to users collection?

There are multiple examples on publish/subscribe but not clear on what is the best practice for storing custom data in the in-built "users" collection in Meteor (especially in the new possibility of template specific collections).
For example, I need to store user browse history - something that is accessible through Meteor.user().settings.history.lastvisited[]
The challenge is:
Is any special publish / subscribe required for the above? (the
reason being, I am assuming the users collection is already
published and available on client side - so do we need another?)
How to take care of edge cases where user is new and hence settings.history object may not be defined? Can we have a special publish that automatically takes care of creating an empty object if the settings is undefined? How to do it?
I did this :
// server side
Meteor.publish('userSettings', function (maxRows) {
if (this.userId) {
return Meteor.users.find({ _id: this.userId }, { fields: {'settings':1}});
}
this.ready();
});
//client side
Meteor.subscribe('userSettings');
But I do not see anyway how I can access the published "userSettings" object on the client side - what is missing ??
You can create a field and set it to false/'', on each user you create using the accountsOnCreateUser method.
Accounts.onCreateUser(function(options, user) {
//this function gets called each time a user has been created on the Meteor.user collection
if (options.profile)
user.settings = ''; //this is just and example.
return user;
})
Now the publish looks ok, but in order to get it work im always use a Tracker.autorun function.
Tracker.autorun(function(){
Meteor.subscribe('userSettings');
})
Why the autorun? well if you don't call the auto run here, the subscription get only called 1 time when the apps loads, and not when the user documents.
Take care of yours deny/allow permissions, check this meteor:common mistakes post on the Profile editing section
Also the subscribe function have a callback function. Meteor.subscribe(name, [arg1, arg2...], [callbacks]), so you can do something like this.
var myUserSubscription = Meteor.subscribe('userSettings',function(){
console.log("ok im here on the client side")
console.log("this user subscription is ready " + myUserSubscription.ready())
})
console.log("outside the subscription why not? " + myUserSubscription.ready();
About ready();
True if the server has marked the subscription as ready. A reactive
data source.

Can't put data from a Meteor collection into an array

I'm learning Meteor and I was trying to pass the result of a Collection.find() into and array (using a variable) and the simpler code I have is (in a file that is in the root):
CalEvents = new Mongo.Collection('calevents'); //creating a collection
/*------------------------- Populating the database with dummy data-------*/
if (Meteor.isServer) {
Meteor.startup(function () {
if (CalEvents.find().count() === 0) {
CalEvents.insert({
title: "Initial room",
start: '2010-02-02'
});
}
});
}
/*--------------- Creating an array from the collection-----------------*/
events = [];
calEvents = CalEvents.find({});
calEvents.forEach(function(evt){
events.push({
title: evt.title,
start: evt.start,
})
});
The page has nothing to show but using the console I can see (CalEvents.find().fetch()) that I have data in my database but the "events" variable is empty...
I can't understand why because I tried several other things such as changing file names and moving code to guarantee the proper order.
And I already tried to use CalEvents.find().fetch() to create an array an put the result into a variable but I'm not able to do it...
Does anyone know what's so simple that I'm missing?...
Do you use autosubscribe?
You probably need to make sure the sbscription is ready. See Meteor: How can I tell when the database is ready? and Displaying loader while meteor collection loads.
The reason you do see CalEvents.find().fetch() returning items in the console is that by the time you make that call, the subscription is ready. But in your events = []; ... code (which I assume is in a file under the client directory, you might have assumed that the subscription data has arrived when in fact it has not.
A useful debugging tool is Chrome's device mode ("phone" icon near the search icon in DevTools), which lets you simulate slow networks (e.g. GPRS, with 500ms delay for every request).

How to prevent a client race condition between Meteor.userId() and subscription updates that depend on userId?

I am seeing a repeatable issue where a user authenticates ("logs in") with a Meteor server, and then a client subscription that depends on userId is updated (and dependent UI templates reactively update) before Meteor.userId() registers the successful login.
For example, in this code snippet, the assert will throw:
var coll = new Meteor.Collection("test");
if (Meteor.isServer) {
Meteor.publish('mineOrPublic', function () {
// Publish public records and those owned by subscribing user
return coll.find({owner: { $in: [ this.userId, null ]}});
});
}
if (Meteor.isClient) {
var sub = Meteor.subscribe('mineOrPublic');
var cursor = coll.find({});
cursor.observe({
added: function (doc) {
if (doc.owner) {
// This should always be true?!
assert(doc.owner === Meteor.userId());
}
}
});
}
Analogous to the added function above, if I write a template helper that checks Meteor.userId(), it will see a value of null, even when it is invoked with a data context of a document with an owner.
There is apparently a race condition between Meteor collection Pub/Sub and the Account userId update mechanisms. It seems to me that Meteor.userId() should always be updated before any subscriptions update based on a change in this.userId in a server publish function, but for some reason the opposite usually seems to be true (that is, the assert in the code above will usually throw).
The reason I care is because I have packages that depend on obtaining a valid Meteor Authentication token (using Accounts._storedLoginToken()) on the client for use in securing HTTP requests for files stored on the Meteor server. And the authentication token isn't correct until Meteor.userId() is. So the flow of events usually goes something like this:
User logs in
Publish function on server reruns based on the change in this.userId.
Client begins receiving new documents corresponding to the change in userId.
UI Template reactively updates to add DOM elements driven by new documents
Some of the DOM elements are <img> tags with src= values that depend on the data context.
HTTP requests are triggered and ultimately fail with 403 (forbidden) errors because the required authentication cookie hasn't been set yet.
Meteor.userId() finally updates on the client, and code reactively runs to set the authentication cookie
Helpers in the template that depend on a session variable set in the cookie update code are rerun, but the DOM doesn't change, because the URLs in the <img> tags don't change.
Because the DOM doesn't change, the tags don't retry their failed attempts to load the images.
Everything settles down, and the user has to manually reload the page to get their images to appear.
I've come up with two possible approaches to work around this issue:
In the template helper that generates the URL for the <img> tag, always append a dummy query string such as: "?time=" + new Date().getTime(). This causes the DOM to change every time the helper is called and fixes the problem, but it screws-up browser caching and if not coordinated will cause some assets to unnecessarily load multiple times, etc.
In every template helper that touches document data add a test of:
if (this.owner && this.owner !== Meteor.userId()) {
// Perhaps Meteor.loggingIn() could be used above?
// Invalid state, output placeholder
} else {
// Valid state, output proper value for template
}
I really hope someone knows of a less kludgy way to work around this. Alternatively, if consensus arises that this is a bug and Meteor's behavior is incorrect in this respect. I will happily file an issue on Github. I mostly really enjoy working with Meteor, but this is the kind of gritty annoyance that grinds in the gears of "it just works".
Thanks for any and all insights.
After trying lots of things, this variation on the example code in the OP seems to consistently solve the race condition, and I find this an acceptable resolution, unlike my initial attempted workarounds.
I still feel that this kind of logic should be unnecessary and welcome other approaches or opinions on whether Meteor's behavior in the OP sample code is correct or erroneous. If consensus emerges in the comments that Meteor's behavior is wrong, I will create an issue on Github for this.
Thanks for any additional feedback or alternative solutions.
var coll = new Meteor.Collection("test");
if (Meteor.isServer) {
Meteor.publish('mineOrPublic', function (clientUserId) {
if (this.userId === clientUserId) {
// Publish public records and those owned by subscribing user
return coll.find({owner: { $in: [ this.userId, null ]}});
} else {
// Don't return user owned docs unless client sub matches
return coll.find({owner: null});
}
});
}
if (Meteor.isClient) {
Deps.autorun(function () {
// Resubscribe anytime userId changes
var sub = Meteor.subscribe('mineOrPublic', Meteor.userId());
});
var cursor = coll.find({});
cursor.observe({
added: function (doc) {
if (doc.owner) {
// This should always be true?!
assert(doc.owner === Meteor.userId());
}
}
});
}
This code works by giving the server publish function the information it needs to recognize when it is running ahead of the client's own login state, thereby breaking the race condition.
I think this is something that Meteor should do automatically: clients should not see documents based on changes to this.userId in a publish function until after the client Meteor.userId() has been updated.
Do others agree?
I tried with this code that works on server too. In association with FileCollection package.
if (Meteor.isServer) {
CurrentUserId = null;
Meteor.publish(null, function() {
CurrentUserId = this.userId;
});
}
....
OrgFiles.allow({
read: function (userId, file) {
if (CurrentUserId !== file.metadata.owner) {
return false;
} else {
return true;
}
}
...

Is there a post createUser hook in meteor when using accounts-ui package?

Let's say I have a todo app, and I want to make sure that every user that registers has at least one todo to start with, something like "First todo to cross off!", how would I do that in meteor?
In general, the way I see it, I can do it when the user is created for the first time (ideal), or check to see whether they need a new todo every time they log in (less ideal). In the latter case, I can do a check for Todos.findOne(), and if the count is 0, add one. However, seems that whether I do this in my router when the page loads, or on some template's .rendered function, the collection I'm checking hasn't been loaded yet, so I always create a new todo, even if one really does exist. So it'd be great if someone could explain how to get around that.
But, what I'd ideally want is the ability to just create a new Todo when the user is created. There is a Accounts.onCreateUser method, but that is used to add additional info to user profile, not a post-create hook. There's also a method to programmatically create the user using Accounts.createNewUser with a callback, but I'm using the accounts-ui package so am not programmatically adding users. In a less ideal case, I could check for the Todo whenever the user logs in, but even in that case, there seems to be a federated Accounts.loginWithXService login, so not sure how to handle the callback when any user logs in, regardless of service type.
I think I must be missing something simple, so apologies if this is super obvious. Any help is appreciated.
The Meteor API now has the hook onCreateUser:
Accounts.onCreateUser(function (options, user) {
Todos.insert({
owner: user._id,
text: "First todo to cross off!",
});
// We still want the default hook's 'profile' behavior.
if (options.profile)
user.profile = options.profile;
return user;
});
I used the _.wrap method described above but wanted to include an additional suggestion. It's a good idea to call the original callback from your new custom callback. Meteor does some things on the callback that we don't want to miss.
Modified code that worked like a champ for me:
Accounts.createUser = _.wrap(Accounts.createUser, function(createUser) {
// Store the original arguments
var args = _.toArray(arguments).slice(1),
user = args[0];
origCallback = args[1];
var newCallback = function(error) {
// do my stuff
origCallback.call(this, error);
};
createUser(user, newCallback);
});
If you are using the UserAccounts package: postSignUpHook now exists.
Splendido just merged my pull request for exactly this issue.
AccountsTemplates.configure({
/*...*/
postSignUpHook: /*[callback with your actions post full user creation goes here]*/,
/*...*/
}
Documentation (You'll need to scroll down it's the last hook):
func(userId, info) Called, server side only, just after a successfull user account creation, post submitting the pwdForm for sign-up: allows for custom actions on the data being submitted after we are sure a new user was successfully created. A common use might be applying roles to the user, as this is only possible after fully completing user creation in alanning:roles. The userId is available as the first parameter, so that user object may be retrieved. The password is not available as it's already encrypted, though the encrypted password may be found in info if of use.
You can piggyback onto functions that are called by Meteor by wrapping them. I'm also using the accounts-ui and accounts-password packages and I use Underscore's _.wrap method to redefine the loginWithPassword function. Underscore is included in Meteor by default.
I use something like this for logging in:
Meteor.loginWithPassword = _.wrap(Meteor.loginWithPassword, function(login) {
// Store the original arguments
var args = _.toArray(arguments).slice(1),
user = args[0],
pass = args[1],
origCallback = args[2];
// Create a new callback function
// Could also be defined elsewhere outside of this wrapped function
var newCallback = function() { console.info('logged in'); }
// Now call the original login function with
// the original user, pass plus the new callback
login(user, pass, newCallback);
});
In this specific case, the code above would go in your client code somewhere.
For Accounts.createUser, it might look something like this (also somewhere in client code):
Accounts.createUser = _.wrap(Accounts.createUser, function(createUser) {
// Store the original arguments
var args = _.toArray(arguments).slice(1),
user = args[0],
origCallback = args[1];
// Create a new callback function
// Could also be defined elsewhere outside of this wrapped function
// This is called on the client
var newCallback = function(err) {
if (err) {
console.error(err);
} else {
console.info('success');
}
};
// Now call the original create user function with
// the original user object plus the new callback
createUser(user, newCallback);
});
Hope that's helpful.
One of the Meteor devs answered this question in Meteor google group: https://groups.google.com/forum/?fromgroups=#!topic/meteor-talk/KSz7O-tt4w8
Basically, right now, there is no createUser hook when using accounts-ui, only when programmatically doing so via Accounts.createUser. Also, there are no hooks for login, unless using the lower-level login functions like loginWithFacebook, etc. I haven't figured out an ideal way around this yet, but a few ways of handling it:
if needing to enter a default value into a collection, in that collection's subscription, use the onComplete argument. In this callback, if there are no entries in collection, add one. This avoids the first problem I mentioned in my post about not knowing when a collection was loaded, though not ideal since collection could be empty because user already removed first default one:
Meteor.subscribe 'todos', user: Meteor.userId(), () ->
todo = Todos.findOne()
unless todo
Todos.insert user: Meteor.userId()
you can set up a login hook by using the Meteor.autorun reactive method to check for a change in Meteor.userId(). That'll only get called when the user logs in/reloads the page. This is more useful for non-collection stuff since the collection is not guaranteed to be loaded when Meteor.userId is set:
Meteor.autorun () ->
if Meteor.userId()
console.log 'Do some post login hook'
So I think the efficient solution is still out there somewhere, but wanted to update this post with workarounds I had found in the meantime.
I think this answer this question better: How can I create users server side in Meteor?
in resume:
Accounts.createUser({
username: username,
email : email,
password : password,
profile : {
//publicly visible fields like firstname goes here
}
});
check the meteor docs for more: http://docs.meteor.com/#/full/accounts_createuser

Meteor collection.insert callback issues

According to the Meteor documentation....
collection.insert(doc, [callback])
callback Function
Optional. If present, called with an error object as the first argument and the _id as the second.
...then later down...
On the server, if you don't provide a callback, then insert blocks until the database acknowledges the write, or throws an exception if something went wrong. If you do provide a callback, insert returns immediately. Once the insert completes (or fails), the callback is called with error and result arguments, same as for methods.
Which is it, error and _id or error and result? I do have Meteor.methods that are firing their callbacks correctly with error, result available to the scope.
I just can't get the callback to work correctly on a collection.insert(doc, [callback])
Either way I can't get my callback to register anything?
function insertPost(args) {
this.unblock;
if(args) {
post_text = args.text.slice(0,140);
var ts = Date.now();
Posts.insert({
post: post_text,
created: ts
}, function(error, _id){
// or try function(error, result) and still get nothing
// console.log('result: ' + result);
console.log('error: ' + error);
console.log('_id: ' + _id); //this._id doesn't work either
});
}
return;
}
What am I doing wrong? I have been up since 2 am coding...6 pm my time zone...I am blurry, so I might (probably) be missing something quite obvious.
Cheers
Steeve
This was a bug, fixed in the next release. Now, if you provide a callback to insert, it will be called with error and result arguments, where result is the ID of the new document, or null if there's an error.
Since this is serverside code you can just do:
var id = Posts.insert({data}); // will block until insert is complete
and the id will be available.

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