Meteor observeChanges removed callback won't execute server methods - meteor

I am observing changes on the Results collection on the client and calling methods on the server for the added and removed callbacks. (The following is only on the client and 'foo' is on the server.)
Results.find().observeChanges({
added: function (id, doc) {
console.log('added on client')
Meteor.call('foo')
},
removed: function (id) {
console.log('removed on client')
Meteor.call('foo')
}
})
Here is the server code.
Meteor.methods({
foo: function() {
console.log('server code run')
}
})
If I insert a document on the client I get 'added on client' on the client and 'server code run' on the server. If I remove a document on the client, I get 'removed on the client' on the client, but nothing on the server at all.
Does anyone know what is going on?

A few suggestions:
Does the code run on the server (e.g if you put it into a Tracker.autorun block)?
Are there any errors on the server console?
Is there any error on the browser console?
If other code within the removed callback gets executed, the server method call will be executed too. There are no restrictions for these callbacks. I don't think your problem is with the code you've pasted. Maybe add the server method code as well.

Related

Insert new collection after function runs on server

When I return the geocode from googles API I'm trying to save it into my database. I've been trying to use the code below, to just insert a Test document with no luck. I think it has something to do with meteor being asynchronous. If I run the insert function before the googleMapsClient.geocode function it works fine. Can someone show me what I'm doing wrong.
Meteor.methods({
'myTestFunction'() {
googleMapsClient.geocode({
address: 'test address'
}, function(err, response) {
if (!err) {
Test.insert({test: 'test name'});
}
});
}
});
I see now where you got the idea to run the NPM library on the client side, but this is not what you really want here. You should be getting some errors on the server side of your meteor instance when you run the initial piece of code you gave us here. The problem is that the google npm library runs in it's own thread, this prevents us from using Meteor's methods. The easiest thing you could do is wrap the function with Meteor.wrapAsync so it would look something like this.
try {
var wrappedGeocode = Meteor.wrapAsync(googleMapsClient.geocode);
var results = wrappedGeocode({ address : "testAddress" });
console.log("results ", results);
Test.insert({ test : results });
} catch (err) {
throw new Meteor.Error('error code', 'error message');
}
You can find more info by looking at this thread, there are others dealing with the same issue as well
You should run the googleMapsClient.geocode() function on the client side, and the Test.insert() function on the server side (via a method). Try this:
Server side
Meteor.methods({
'insertIntoTest'(json) {
Test.insert({results: json.results});
}
});
Client side
googleMapsClient.geocode({
address: 'test address'
}, function(err, response) {
if (!err) {
Meteor.call('insertIntoTest', response.json);
}
});
Meteor Methods should be available on the both the server and client sides. Therefore make sure that your method is accessible by server; via proper importing on /server/main.js or proper folder structuring.
(If a method contains a secret logic run on the server, it should be isolated from the method runs on both server & client, though)

How do I reliably pull data from Meteor server collections to client collections when using an existing mongodb as MONGO_URL?

I know that there are several methods to share collections on both the client and server -- namely either in top level lib folder or publish/subscribe model -- but when I try either of these things when using mongodb running at localhost:27017 as my MONGO_URL, I am not reliably getting data on the client. Occasionally console.log(myCollection.findOne({})) will return expected data in the browser but most of the time it returns undefined.
//Client side code
Template.controls.onCreated(function controlsOnCreated() {
Meteor.subscribe("myEvents");
Events = new Mongo.Collection("events");
});
//Server side code
Meteor.startup(() => {
Events = new Mongo.Collection("events");
}
Meteor.publish('myEvents', function() {
console.log(Events.find());
return Events.find();
});
UPDATED CODE -- returns Events on server but not client:
//Client
Template.controls.onCreated(function controlsOnCreated() {
this.subscribe("myEvents");
});
//Server
if (Meteor.isServer) {
Meteor.publish("myEvents", function() {
return Events.find();
});
}
// /collections/events.js
Events = new Mongo.Collection("events");
UPDATE 2:
I am attempting to verify the publication in the browser after the page has rendered, calling Events.findOne({}) in the Chrome dev tools console.
on your client:
Template.controls.onCreated(function controlsOnCreated() {
Meteor.subscribe("myEvents");
Events = new Mongo.Collection("events");
});
that is an odd place to define the Events variable. typically, you would put that line of code in a JS file common to both platform. e.g.
collections/events.js:
Events = new Mongo.Collection("events");
when that line runs on the server, it defines the mongo collection and creates a server-side reference to it. when it runs on the client, it creates a collection by that name in mini-mongo and creates a client-side reference to it.
you can write your onCreated like this (note "this" instead of "Meteor"):
Template.controls.onCreated(function() {
this.subscribe("myEvents");
});
you don't say where on the client you ran your console.log with the find(). if you did it in the onCreated(), that's too early. you're seeing the effects of a race condition. typically, you might use it in a helper:
Template.controls.helpers({
events() {
return Events.find({});
}
});
and display the data in the view:
{{#each event in events}}
{{event.name}}
{{/each}}
that helper will run reactively once the data from the publish shows up.

meteor.call does not call method from meteor.method

i have an issue with callback method.
i have created on methods.js in server folder
and one callback.js file in client/test/mytest folder.
my callback.js contains following code
Template.testHello.events({
"click #testHello": function(e) {
Meteor.call("testmethod",function(error, id) {
if (error) {
Errors.throwError(error.reason);
}
return false;
});
return false;
}
});
and methods.js file code is
Meteor.methods({
testmethod: function(att) {
alert("hello testmethod..");
}
});
but when i clicked on button "testHello" then it gives me error like "internal server error 500".
can anyone have idea about this?
Thanks,
It makes no sense to have client-only method calls because Meteor methods are intended to perform RMI (remote method invokation) on the server.
Move your methods.js to either server/methods.js or lib/methods.js if you want your method to have a simulation counterpart on the client.
EDIT :
As hinted by #user728291, the alert method is defined on the window object which is a browser related object thus only available on client environment, you can use console.log instead to print something on the server.

Meteor.http.call gives not allowed by Access-Control-Allow-Origin

When I try to call an external server for JSON queries in Meteor with the Meteor.http.call("GET") method I get the error message "not allowed by Access-Control-Allow-Origin".
How do I allow my meteor app to make HTTP calls to other servers?
Right now I run it on localhost.
The code I run is this:
Meteor.http.call("GET",
"http://api.vasttrafik.se/bin/rest.exe/v1/location.name?authKey=XXXX&format=json&jsonpCallback=processJSON&input=kungsportsplatsen",
function(error, result) {
console.log("test");
}
);
There are other questions similar to this on StackOverflow.
You're restricted by the server you're trying to connect to when you do this from the client side (AJAX).
One way to solve it is if you have access to the external server, you can modify the header file to allow some, or all origins by:
Access-Control-Allow-Origin: *
However, if you place the call on the server side and not provide a callback function, the call will be made synchronously, thus not with AJAX, and it should succeed.
Here's
Meteor.methods({checkTwitter: function (userId) {
this.unblock();
var result = Meteor.http.call("GET", "http://api.twitter.com/xyz", {params: {user: userId}});
if (result.statusCode === 200) return true
return false;
}});

Meteor - Using collection on client startup

Why this code shows "0"? Shouldn't it return "1"?
Messages = new Meteor.Collection("messages");
if (Meteor.is_client) {
Meteor.startup(function () {
alert(Messages.find().count());
});
}
if (Meteor.is_server) {
Meteor.startup(function () {
Messages.insert({text: "server says hello"});
});
}
If I do the "Messages.find().count()" later, it returns 1.
By default, when a Meteor client starts up, it connects to the server and subscribes to documents in any Meteor.Collection you defined. That takes some time to complete, since there's always some amount of delay in establishing the server connection and receiving documents.
Meteor.startup() on the client is a lot like $() in jQuery -- it runs its argument once the client DOM is ready. It does not wait for your client's collections to receive all their documents from the server. So the way you wrote the code, the call to find() will always run too early and return 0.
If you want to wait to run code until after a collection is first downloaded from the server, you need to use Meteor.subscribe() to explicitly subscribe to a collection. subscribe() takes a callback that will run when the initial set of documents are on the client.
See:
meteor-publish
and meteor-subscribe
Just to follow up with a code example of how to know when a collection is ready to use on the client.
As #debergalis described, you should use the Meteor.subscribe approach - it accepts a couple of callbacks, notably onReady
For example:
if(Meteor.isClient){
Meteor.subscribe("myCollection", {
onReady: function(){
// do stuff with my collection
}
});
}

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