Develop Reference

Meteor: publish dynamically requested range of items

I have huge collection of over 5000+ records. I want to be able to view records 10 at a time. How can I dynamically publish the data that way?
I've tried this so far:
My server.js file :
Meteor.methods({
publishSongs : function (first, last) {
Meteor.publish('adminSongs', function() {
return Songs.find({}, {
skip : first,
limit : last,
sort : {
date : -1
}
});
});
}
});
My client.jsfile :
Template.admin.events({
'click #previous' : function() {
updateSession(-10);
publishSong();
},
'click #next' : function() {
updateSession(10);
publishSong();
}
});
Template.admin.onCreated(function() {
Session.setDefault('limit', {
first : 0,
last : 10
});
publishSong()
})
function publishSong() {
Meteor.call(
'publishSong',
Session.get('limit').first,
Session.get('limit').last
);
}
function updateSession(value) {
Session.set('limit', {
first: Session.get('limit').first + value,
last: Session.get('limit').last + value,
});
}
The server is printing this error message:
Ignoring duplicate publish named 'adminSongs'
It seems like I'm using publications wrong and could use some guidance.

It doesn't look like you're never updating your Session.get('limit'). You'll need to update then you press next/previous otherwise you're always going to get the same records. You'll also need to change the way you're doing publications:
Template.admin.events({
'click #previous' : function() {
updateSession(-10);
},
'click #next' : function() {
updateSession(10);
}
});
Template.admin.onCreated(function() {
Session.setDefault('limit', {
first : 0,
last : 10
});
Template.instance().autorun( function() {
Template.instance().subscribe('adminSongs', Session.get('limit').first, Session.get('limit').last);
});
});
function updateSession(value) {
Session.set('limit', {
first: Session.get('limit').first + value,
last: Session.get('limit').last + value,
});
}
I'm assuming based on your code that you already have a helper defined to return the available songs. The code above makes it so that you have one subscription, and that subscription will update any time your session variable changes.
Your server code will also need to be updated:
Meteor.publish('adminSongs', function(first, last) {
return Songs.find({}, {
skip : first,
limit : last,
sort : {
date : -1
}
});
});
Can be outside of a Meteor.method.

How can I update a complex knockout observable programatically?

I'm using durandal/requirejs/knockout here.
I'm also using the coderenaissance plugin for mapping (ko.viewmodel.updateFromModel(zitem, data).)
I'm getting the following data from my ajax call which I'm mapping into my zitem observable.
{
"itemNumber" : "ABATAH000",
"effectiveDate" : "2015-11-03T15:30:05.7118023-05:00",
"expiryDate" : "2015-05-03T15:30:05.7118023-04:00",
"minimumPremium" : 25,
"zSubItems" : [{
"zSubItemName" : "Mine",
"unitDistance" : 100000,
"zSubSubItems" : [{
"zSubSubItemName" : "CoverageA",
"zSubSubItemPremium" : 100.0,
"id" : 0
}
],
"id" : 1
}
],
"id" : 0
}
And here is the viewmodel I'm using:
define(['plugins/http', 'durandal/app', 'knockout', 'services/datacontext'],
function (http, app, ko, datacontext) {
var zitem = ko.observable();
var activate = function () {
//This is just a wrapper around an ajax call.
return datacontext.getPolicy("value")
.then(function(data) {
ko.viewmodel.updateFromModel(zitem, data);
});
};
var updateMinimumPremium = function (thisItem) {
//This doesn't work
zitem.minimumPremium(thisItem.minimumPremium + 1);
};
return {
displayName: 'zitem example',
zitem: zitem,
updateMinimumPremium: updateMinimumPremium,
activate: activate
};
});
I'm binding the updateMinimumPremium to a click on a button at the same level as the minimumPremium element.
<button data-bind="click: $parent.updateMinimumPremium">Add 1</button>
How can I update [minimumPremium] or [zSubSubItemPremium] programatically?

"minimumPremium" would be observable
zitem.minimumPremium(thisItem.minimumPremium() + 1);

Your zitem is observable as well, so try this:
zitem().minimumPremium(thisItem.minimumPremium + 1);
In real application don't forget to check the value of zitem() call - it can be uninitialized.

ReferenceError: $firebase is not defined

I am trying to unit test this service using jasmine:-
my unit test is :-
describe('initial configuration for the test user', function () {
beforeEach(function(){
var config = {
'Apache 404' : {
content : {
type : 'tip',
template : 'yesNo',
text : 'Are you searching for status code 404?',
yesText : 'Try our more accurate field search',
attachTo : '#inputBox right',
yesActions : {
0 : {
type : 'replaceSubstring',
target : '#inputBox',
value : 'apache.status:404',
match : '404'
}
}
},
conditions : {
0 : {
type : 'valueChange',
target : '#inputBox',
textMatch : '(^|([\\s]+))404(([\\s]+)|$)',
preventSubmit : true
},
1 : {
type : 'contentPropertyLessThan',
propertyName : 'timesShown',
compareVal : 3
}
}
}
};
var clientName = 'testClient';
var fireRef = new Firebase('https://luminous-inferno-1740.firebaseio.com/' + clientName);
var fireSync = $firebase(fireRef);
fireSync.$set({'config' : config});
log.message = 'Resetting user data';
$log.debug(log);
userData.init(function(done) {
done();
});
});
it('should have a valid config', function () {
expect(Object.keys(userData.getConfig()).length > 1);
});
});
I am receiving an error :-
ReferenceError: $firebase is not defined
at Object.
Can somebody help me providing working example of my code with some explanation?

I also had the problem. I solved my problem by adding $firebaseArray in the parameter of the controller
.controller('ChatsCtrl', ['$scope','$firebaseArray','$rootScope',......
One thing should be noted that firebase has been updated that $firebase is no longer supported. You can only use $firebaseArray or $firebaseObject for retrieving the data.

Model doesn't change when modify view elements in backbone.js

I am validating model's attribute (Name), in order to make sure, customer have to input their name in the register form.
View :
define(["jquery" ,
"underscore" ,
"backbone" ,
"text!templates/CustomerTemplate.html",
"models/Customer"
],function($ , _ , Backbone, CustomerTemplate, CustomerModel){
var CustomerView = Backbone.View.extend({
initialize : function(){
this.listenTo(this.model, 'change', this.render);
},
events : {
'submit #customerForm' : 'Customer'
},
Customer : function(e){
e.preventDefault()
var _customer = new CustomerModel({
UID: "00000000-0000-0000-0000-000000000000",
Sex: 0,
Name: $("#name").val(),
});
this.model.save(_customer,{validate: true},{
wait:true,
success:function(model, response) {
console.log('Successfully saved!');
},
error: function(model, error) {
console.log(model.toJSON());
console.log('error.responseText');
}
});
},
render : function(){
var customertemplate = _.template(CustomerTemplate);
this.$el.html(customertemplate(this.model.toJSON()));
return this;
}
});
return CustomerView;
});
Model:
define(["underscore" , "backbone"],function(_ , Backbone){
var CustomerModel = Backbone.Model.extend({
urlRoot: "myurl",
initialize : function(){
this.bind('invalid', function(model, error) {
console.log(error);
});
},
validate: function (attrs){
if ( !attrs.Name) {
return 'You must provide a name';
}
},
defaults : {
UID: "00000000-0000-0000-0000-000000000000",
Sex: 0,
Name: "",
}
});
return CustomerModel;
});
Problem : Even the attribute Name is not null, the error message in validate method still appears (You must provide a name).
Any idea what could be causing this is appreciate. Thanks.

When you call this.model.save in your CustomerView, you're passing it a new Customer model you instantiated in the previous statement. This isn't quite what you want; you either want to call _customer.save() to save the brand new model, or - more likely - you want to pass your new attributes to the existing model, and save that:
var newAttrs = {
UID: "00000000-0000-0000-0000-000000000000",
Sex: 0,
Name: $("#name").val(),
};
this.model.save(newAttrs);
When you call this.model.save(_customer, {validate: true}) in your existing code, that Customer model get passed to your validate() function. And that model doesn't have a Name attribute. It does have a Name property - you can access it via _customer.get('Name') - but you should follow the Backbone convention and presume that your validate method is getting a 'simple' JavaScript object, not a Backbone model.

Unexpected behavior in my code

I have the following code:
var myApp = {
Models: {},
Views: {},
Collections: {},
Controllers: {},
init: function() {
new this.Controllers.Main();
Backbone.history.start();
}
}
myApp.Models.User = Backbone.Model.extend({
idAttribute : '_id',
url : 'currentUser',
initialize : function() {
this.fetch();
}
});
myApp.Controllers.Main = Backbone.Controller.extend({
initialize: function() {
this.currentUser = new myApp.Models.User();
},
routes: {
'' : 'index',
},
index: function() {
console.log('index called');
console.log(this.currentUser); // shows the correct object
console.log(this.currentUser.attributes); // empty object ?
console.log(this.currentUser.toJSON()); // empty object ?
console.log(this.currentUser.get('name')); // undefined ?
}
});
$(function() {
myApp.init();
});
What am i missing ?

This is an asynchronous problem. Fetch is doing an asynchronous Ajax call, it will return but no values will be set yet. Do something like that:
this.currentUser.bind("change:id", function(){
//your console logs
});
When the fetch succeed and an id is set on the model, the logs will be called.

If you do new myApp.Models.User(); , you create a new empty User .. How could it have attributes ..
You didn't specify an id so how could it be fetched from the server ?
And you didn't specify defaults values ..
So it seems coherent to me, no ?