Cannot acces properties of resulting array of cursor.fetch(); - meteor

I have a helper where I want to acces the properties of a different collection.
Template.notification.helpers({
username: function () {
game = Games.findOne({_id: this.gameId}, {fields: {players:1}});
console.log(game) // output is correct
}
})
If I log this, it wil produce the result I expected:
Object {players: Array[2], _id: "qF3skjX2755BYcr8p"}
However, if I in my helper function I try to use/reach this properties I get an undefined error.
Template.notification.helpers({
username: function () {
game = Games.findOne({_id: this.gameId}, {fields: {players:1}});
console.log(game._id) // error;
console.log(game.players) // error
}
})
Output:
Exception from Deps recompute function: TypeError: Cannot read property 'players' of undefined
Why is this happening?

This happens because when Meteor initiall loads on your web browser, all the html and js is ready, but the data is not yet ready.
If you tried to check console.log(game) it may be null. It does this only when the page has loaded. If you load the template after all the data has downloaded you wouldn't see this issue.
When the data arrives the username helper would re-run with the new data.
In the meanwhile you just need to take care of this exception:
var game = Games.findOne({_id: this.gameId}, {fields: {players:1}});
if(!game) return null;

Related

Cannot read property of undefined, but property exists

I am getting a curious error in a template helper and I was hoping someone could lay eyes on it with me. Basically the error I'm getting in the console of the client is that the getArena().height is undefined. However, console.log(getArena().height) returns the correct property value. It appears to be a timing issue causing me to get the error, but my application is actually working. What can I do to alleviate this console error?
//My template helper function
yGrids: function() {
console.log(getArena);
console.log(getArena().height);
var yArray = [];
for (var i=0;i<(getArena().height);i++){
yArray.push({});
}
return yArray;
},
// The console results
function getArena() { // 50
return Arenas.findOne(Session.get('arena_id')); …
Exception in template helper: TypeError: Cannot read property 'height' of undefined
at Object.yGrids (http://localhost:3000/app/app.js?hash=c17abf51d6af6541e868fa3fd0b26e34eea2df28:94:35)
at http://localhost:3000/packages/blaze.js?hash=ef41aed769a8945fc99ac4954e8c9ec157a88cea:2994:16
at http://localhost:3000/packages/blaze.js?hash=ef41aed769a8945fc99ac4954e8c9ec157a88cea:1653:16
at http://localhost:3000/packages/blaze.js?hash=ef41aed769a8945fc99ac4954e8c9ec157a88cea:3046:66
at Function.Template._withTemplateInstanceFunc (http://localhost:3000/packages/blaze.js?hash=ef41aed769a8945fc99ac4954e8c9ec157a88cea:3687:12)
at http://localhost:3000/packages/blaze.js?hash=ef41aed769a8945fc99ac4954e8c9ec157a88cea:3045:27
at Object.Spacebars.call (http://localhost:3000/packages/spacebars.js?hash=65db8b6a8e3fca189b416de702967b1cb83d57d5:172:18)
at http://localhost:3000/app/app.js?hash=c17abf51d6af6541e868fa3fd0b26e34eea2df28:24:22
at .<anonymous> (http://localhost:3000/packages/blaze.js?hash=ef41aed769a8945fc99ac4954e8c9ec157a88cea:2754:17)
at http://localhost:3000/packages/blaze.js?hash=ef41aed769a8945fc99ac4954e8c9ec157a88cea:1875:20
function getArena() { // 50
return Arenas.findOne(Session.get('arena_id')); …
2
This is a very common issue in Meteor helpers when referring to a collection which may not yet have been loaded via a subscription. In general you want to show a loading template instead of your actual layout until your subscription is ready. Or (less elegant) you can defend yourself with:
var arena = getArena();
var height = arena && arena.height;
Whatever getArena() returns you ought to store it in the reactive variable by setting the reactive variable and you can access the reactive var in helper by get() method

Is there a way to update the URL in Flow Router without a refresh/redirect?

Is there a way to update a part of the URL reactively without using FlowRouter.go() while using React and react-layout?
I want to change the value in the document that is used to get the document from the DB. For example, if I have a route like ~/users/:username and update the username field in the document, I then have to user FlowRouter.go('profile', {data}) to direct the user to that new URL. The "old" route is gone.
Below is the working version I have, but there are two issues:
I have to use FlowRouter.go(), which is actually a full page refresh (and going back would be a 404).
I still get errors in the console because for a brief moment the reactive data for the component is actually wrong.
Relevant parts of the component are like this:
...
mixins: [ReactMeteorData],
getMeteorData() {
let data = {};
let users = Meteor.subscribe('user', {this.props.username});
if (user.ready())
data.user = user;
return data;
}
...
updateName(username) {
Users.update({_id:this.data.user._id}, {$set:{username}}, null, (e,r) => {
if (!e)
FlowRouter.go('profile', {username});
});
},
...
The route is like this:
FlowRouter.route('/users/:username', {
name: 'profile',
action(params) {
ReactLayout.render(Main, {content: <UserProfile {...params} />});
}
});
The errors I get in the console are:
Exception from Tracker recompute function:
and
TypeError: Cannot read property '_id' of undefined

returning cursor results causes "stack size exceeded" error

I have a page that lists a company's profile and shows its open jobs. I use iron-router to get the companies profile info, but use a Meteor.call to get active jobs once the page has been loaded. However, when I return a cursor it throws a stack size exceeded error.
organization.js
Template.organization.rendered = function() {
Meteor.call('getActiveJobs', function(error, jobs){
if(error){
console.log(error);
} else {
console.log(jobs);
}
});
}
collection
Meteor.methods({
.....
getActiveJobs: function(){
return Jobs.find({organizationId: user.profile.organizationId});
}
.....
});
this throws a "RangeError: Maximum call stack size exceeded" error.
However, I can return
return Jobs.find({organizationId: user.profile.organizationId}).fetch();
without an error, but I'm trying t return the cursor so it's easier to work with using handlebars, but I don't quite understand why I'm getting this error.
Please note, that the values returned from your method need to be transferred from server to client in the JSON format. It follows that you cannot return Objects which are not JSON-serializable (there are small exceptions here, but we can forget about them for now).
If you want to return a cursor you should use Meteor.publish instead of Meteor.methods, so
Meteor.publish('activeJobs', function () {
var user = Meteor.users.findOne({_id: this.userId});
return Jobs.find({organizationId: user.profile.organizationId});
});
Also, remember to call Meteor.subscribe('activeJobs') on the client as soon as you need this data set.

Meteor client side collection needs to have all data populated before anything else

I'm trying to use a client side collection as a site configuration system. I insert documents representing my different pages, and the iron-router and navigation tabs all use them to determine what pages they are and what templates are represented by them. Each page uses a {{> contentTemplate}} inclusion helper to load it's relevant template.
It all works great, when the data has all loaded. When I restart the app on certain pages, the data hasn't loaded yet, and I receive the Exception from Deps recompute function: Error: Expected null or template in return value from inclusion function, found: undefined error.
Here's my javascript:
StoriesArray = [
{ category: 'teaching', contentTemplate: 'teachingHome', title: 'Teaching Home'},
...
];
Stories = new Meteor.Collection(null);
StoriesArray.forEach(function (story, index) {
story._id = index + '';
Stories.insert(story);
});
// in main.js
Template.teachingPost.contentTemplate = function() {
console.log(this);
console.log(this.contentTemplate);
return Template[this.contentTemplate];
};
// in router.js
this.route('teaching', {
layoutTemplate: 'teachingPost',
data: function() { return Stories.findOne({contentTemplate: 'teachingHome', category: 'teaching'}); }
});
The console logs in the contentTemplate helper above log twice, the first time as this:
Object {} main.js?1f560c50f23d9012c6b6dd54469bb32b99aa4285:45
undefined main.js?1f560c50f23d9012c6b6dd54469bb32b99aa4285:46
and the second time as this:
Object {category: "teaching", contentTemplate: "teachingHome", title: "Teaching Home"} main.js?1f560c50f23d9012c6b6dd54469bb32b99aa4285:45
teachingHome main.js?1f560c50f23d9012c6b6dd54469bb32b99aa4285:46
so the router is simply trying to load this data too early.
I've tried putting the StoriesArray loading process into different files all over my app, including lib, and even tried putting it into Meteor.startup, but it's always the same result.
The normal iron-router waitOn/subscription pattern doesn't really apply here, since this is a client side collection built with null, that has no server representation. I don't want this to have server representation, because this is static content that there's no need to go to my server for.
How do I ensure this information is done before continuing?
Untested, but per Iron Router's docs on waitOn:
Returning a subscription handle, or anything with a ready method from the waitOn function will add the handle to a wait list.
Also in general it's better to use find with data, rather than findOne, as find will return an empty cursor when the collection is empty as opposed to findOne returning undefined. So try this:
// in router.js
this.route('teaching', {
layoutTemplate: 'teachingPost',
data: function() {
return Stories.find({contentTemplate: 'teachingHome', category: 'teaching'});
},
waitOn: function() {
var handle = {};
handle.ready = function() {
if (Stories.find().count() !== 0)
return true;
else
return false;
}
return handle;
}
});
And adjust your Template.teachingPost.contentTemplate function to work with a cursor rather than an object.

angularFireCollection is not returning any data

I have no issues when using implicit updates (angelFire). However I need for some of my data use explicit updating. So I implemented angelFireCollection on the exact same ref I was using previously but despite the console.log explicitly saying that the read was granted and trying it with both with the onloadcallback and without, I don't get data directly into my assigned variable AND once the callback fires I get a strange looking object that DOES contain the data but not in the form I expect. My scope variable ends up with an empty collection. Never gets populated. Here is the code:
var streamController = function ($rootScope, $scope, $log, $location, angularFireCollection, profileService) {
//Wait for firebaseLogin...
$rootScope.$watch('firebaseAuth', init);
function init() {
if ($rootScope.firebaseAuth == false) {
return
};
var refUsers = new Firebase($rootScope.FBURL+'/users/'+$rootScope.uid);
$scope.profile = angularFireCollection(refUsers, function onload(snapshot) {
console.log(snapshot)
});
};
};
myApp.gwWebApp.controller('StreamController', ['$rootScope', '$scope', '$log', '$location', 'angularFireCollection', 'profileService',
streamController]);
}());
Here is what the console.log looks like ( ie; what snapshot looks like ):
>snapshot
T {z: R, bc: J, V: function, val: function, xd: function…}
Here is the earlier message before the snapshot was returned:
Firebase Login Succeeded! fbLoginController.js:16
FIREBASE: Attempt to read /users/529ccc5d1946a93656320b0a with auth={"username":"xxxxxxx#me.com","id":"529ccc5d1946a93656320b0a"} firebase.js:76
FIREBASE: /: "auth.username == 'admin'" firebase.js:76
FIREBASE: => false firebase.js:76
FIREBASE: /users firebase.js:76
FIREBASE: /users/529ccc5d1946a93656320b0a: "auth.id == $user" firebase.js:76
FIREBASE: => true firebase.js:76
FIREBASE:
FIREBASE: Read was allowed.
and finally the desired binding that ends up with an empty array: again from the console:
$scope.profile
[]
Anyone know what I could possibly be doing wrong?? This is like 5 lines of code. Frustrating.
I have put stops in angelFireCollection factory function and can see that the data is getting added to the collection in the callbacks inside that function but my binded variable never gets updated.
UPDATE
Ok experimenting with a plnkr. It seems that angularFireCollection EXPECTS your returning a LIST of items. The snapshot returns properly if you inspect snapshot.val() it will be whatever object structure was stored in firebase. IF you use angularFireCollection it does indeed bind to the variable HOWEVER it turns a non-list object into a garbled mess and you can not access the object user the normal dot operator. This is either a bug or it is a severe limitation of angularFireCollection which will cause me to revaluate how easily I can use firebase as the backend. I can't share my plnkr because it is accessing non-public data but tomorrow if i have time I will create a public firebase with an object store and demonstrate.
Ok. So it appears that indeed angularFireCollection is MEANT to be array based. Which is fine. It would be VERY helpful if the angularFire documentation was updated to make that clear. As such it is not an implicit vs explicit update technique.
For an explicit non-array based approach I have come up with the following code. Had I not been mislead by the documentation I would have gone down this path originally.
var MainCtrl = function($scope, angularFire) {
$scope.test = {};
var _url = 'https://golfwire.firebaseio.com/tmp';
var _ref = new Firebase(_url);
var promise = angularFire(_ref, $scope, 'implicit');
promise.then ( function(data){
$scope.explicit=angular.copy($scope.implicit );
});
}
You then work locally with the 'explicit' copy and when ready just update the 'implicit' by assigning: $scope.implicit = $scope.explicit.
Here is a plnkr: http://plnkr.co/edit/bLJrL1

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