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dynamic observable classes for knockout

I am working on a reporting related project, where I need to build lot of reports rendered using KO. All data pulled using AJAX and the model is updated. Currently I am writing tons of js functions to map the models. Something like:
function modelx(child) {
var self = this;
self.Name = ko.observable(child.Name);
self.Relation = ko.observable(child.Relation);
// hundred other properties
};
function modely(child) {
var self = this;
self.Age = ko.observable(child.Age);
self.Relation = ko.observable(child.Relation);
// hundred other properties
};
and after AJAX call, I am filling the observable arrays
for (var i = 0; i < jsn.length; i++)
{
VM.modelxlist().push(new modelx(jsn[i]));
}
for (var i = 0; i < jsn1.length; i++)
{
VM.modelylist().push(new modely(jsn1[i]));
}
Is there any way to avoid the definition of modelx, modely,... such that the model is automatically built without loosing the benefits of this approach while using in HTML? Of course there could be a corner case where I may not get a specific property from server, which I should check on the server side.
Also, at times I may need to add additional computed observables (just to be more flexible)

Why don't you use knockout mapping plugin:
http://knockoutjs.com/documentation/plugins-mapping.html
You would then have something like:
var modelxInstance= ko.mapping.fromJS(child);
There are a few mapping plugins for knockout, the one i like the most is actually this one:
https://github.com/LucasLorentz/knockout.mapper
And the reason is that it is more configurable and it is faster.

I think this is what you want..
With ko.mapping.fromJS method u can automatically observe all the properties from your object..
Take some time to read about that..

Create a copy of a module instead of an instance in Node.js

this would be my first question ever on stackoverflow, hope this goes well.
I've been working on a game (using corona SDK) and I used Node.js to write a small little server to handle some chat messages between my clients, no problems there.
Now I'm working on expanding this little server to do some more, and what I was thinking to do is create an external file (module) that will hold an object that has all the functions and variables I would need to represent a Room in my games "Lobby", where 2 people can go into to play one against the other, and each time I have 2 players ready to play, I would create a copy of this empty room for them, and then initialize the game in that room.
So I have an array in my main project file, where each cell is a room, and my plan was to import my module into that array, and then I can init the game in that specific "room", the players would play, the game will go on, and all would be well... but... my code in main.js:
var new_game_obj = require('./room.js');
games[room_id] = new_game_obj();
games[room_id].users = [user1_name,user2_name];
Now, in my room.js, I have something of the sort:
var game_logistics = {};
game_logistics.users = new Array();
game_logistics.return_users_count = function(){
return game_logistics.users.length;
}
module.exports = function() {
return game_logistics;
}
So far so good, and this work just fine, I can simply go:
games[room_id].return_users_count()
And I will get 0, or 1, or 2, depending of course how many users have joined this room.
The problems starts once I open a new room, since Node.js will instance the module I've created and not make a copy of it, if I now create a new room, even if I eliminated and/or deleted the old room, it will have all information from the old room which I've already updated, and not a new clean room. Example:
var new_game_obj = require('./room.js');
games["room_1"] = new_game_obj();
games["room_2"] = new_game_obj();
games["room_1"].users = ["yuval","lahav"];
_log(games["room_1"].return_user_count()); //outputs 2...
_log(games["room_2"].return_user_count()); //outputs 2...
Even doing this:
var new_game_obj = require('./room.js');
games["room_1"] = new_game_obj();
var new_game_obj2 = require('./room.js');
games["room_2"] = new_game_obj2();
games["room_1"].users = ["yuval","lahav"];
_log(games["room_1"].return_user_count()); //outputs 2...
_log(games["room_2"].return_user_count()); //outputs 2...
Gives the same result, it is all the same instance of the same module in all the "copies" I make of it.
So my question as simple as that, how do I create a "clean" copy of my original module instead of just instancing it over and over again and actually have just one messy room in the end?

What you're doing is this (replacing your require() call with what gets returned);
var new_game_obj = function() {
return game_logistics;
}
So, every time you call new_game_obj, you return the same instance of game_logistics.
Instead, you need to make new_game_obj return a new instance of game_logistics;
// room.js
function Game_Logistics() {
this.users = [];
this.return_users_count = function(){
return this.users.length;
};
}
module.exports = function() {
return new Game_Logistics();
}
This is quite a shift in mentality. You'll see that we're using new on Game_Logistics in module.exports to return a new instance of Game_Logistics each time it's called.
You'll also see that inside Game_Logistics, this is being used everywhere rather than Game_Logistics; this is to make sure we're referencing the correct instance of Game_Logistics rather than the constructor function.
I've also capitalized your game_logistics function to adhere to the widely-followed naming convention that constructor functions should be capitalized (more info).
Taking advantage of the prototype chain in JavaScript is recommended when you're working with multiple instances of functions. You can peruse various articles on "javascript prototypical inheritance* (e.g. this one), but for now, the above will accomplish what you need.

Knockout js gathering data from other view models

I have an app that uses several different view models (this is the first time I have built an app with knockout js).
Basically what I'm doing is a wizard and each page is a knockout view model, at the end I'd like to take all the json from all the view models and submit it with a final button.
What would be the best way of doing this?

window.firstViewModel = new function()
{
var self = this;
self.firstProperty = ko.observable();
//
}
window.secondViewModel = new function()
{
var self = this;
self.secondProperty = ko.observable();
//
}
var submit = function()
{
var firstProperty = firstViewModel.firstProperty(); // access to firstViewModel
var secondProperty = secondViewModel.secondProperty(); // access to secondViewModel
//...
}

I would recommend going towards a Single Page Application.
Essentially, you would have a single view model with sections for each step in the wizard, and on submit, you have all the data you need.
The visibility/aesthetics can be controlled via css and intelligent binding.
RP Niemeyer has a good demo, and also talks about it in this answer.

Confused about complex class structure and Knockout

Been getting into Knockout and and slowly getting used to it. Trying to use it in a new project, but am having a hard time getting things lined up to work. While I understand and can do simple examples (simple form with text boxes bound to ko.observables, or a table or list bound to a ko.observableArray), I can't get the syntax right for a combination, especially if I want to convert the data to JSON format in order to transmit it, via a webservice, to be saved into a database.
Basically it's a data entry form, with some text entry boxes, then a list of items (think company information + a list of it's employees).
I have a sample Fiddle here: http://jsfiddle.net/rhzu6/
In the saveData function, I just don't know what to do to get the data packaged. Doing ko.toJS(self) just shows "Object".
I tried defining the data as objects, but quickly got lost:
function Company(CompanyName, ZipCode) {
var self = this;
self.ZipCode = ko.observable(ZipCode);
self.CompanyName = ko.observable(CompanyName );
self.Employees = ko.observableArray();
}
function Employee(FirstName, LastNameB) {
var self = this;
self.FirstName = ko.observable(FirstName);
self.LastName = ko.observable(LastName);
}
Then the ViewModel looked like:
function viewModel() {
var self = this;
self.Company = ko.observable(); // company?
self.Employees = ko.observableArray(); // ?
}
But ran into the same issue. And also had binding problems - data-bind:"value: CompanyName" threw an exception saying it didn't know what CompanyName was...
Color me stumped. I'm sure it's something easy that I'm just missing.
Any and all help would be appreciated!
Thanks

You are looking for ko.toJSON which will first call ko.toJS on your ViewModel and afterwards JSON.stringify.
ko.toJS will convert your knockout model to a simple JavaScript object, hence replacing all observables etc. with their respective values.
I updated your Fiddle to demonstrate.
For more info, take a look at this post from Ryan Niemeyers blog.
An alternative is to make use of ko.utils.postJson:
ko.utils.postJson(location.href, {model: ko.toJS(viewModel) });
Notice the ko.toJS again.

It looks to me as if you (semantically) want to submit a form. Therefore, I think that you should use the submit binding. The biggest benefit is that you listen to the submit event, which allows submit by other means, such as Ctrl+Enter or any other keyboard combination you want.
Here is an example on how that submitEvent handler could look like. Note that it uses ko.mapper, which is a great way to create a viewModel from any JS/JSON-object you want. Typically, you would have
[backend model] -> serialization -> [JS/JSON-ojbect] -> ko.mapper.fromJSON(obj) -> knockout wired viewModel.
viewModel.submitEvent = function () {
if (viewModel.isValid()) { //if you are using knockout validate
$.ajax(
{
url: '/MyBackend/Add',
contentType: 'application/json',
type: 'POST',
data: ko.mapping.toJSON(viewModel.entityToValidateOnBackend),
success: function (result) {
ko.mapping.fromJSON(result, viewModel);
}
}
);
}
};
Good luck!

Advice needed... Javascript OOP/namespacing

right now i am at a point where i feel that i need to improve my javascript skills because i already see that what i want to realize will get quite complex. I've iterrated over the same fragment of code now 4 times and i am still not sure if it's the best way.
The task:
A user of a webpage can add different forms to a webpage which i call modules. Each form provides different user inputs and needs to be handled differently. Forms/Modules of the same type can be added to the list of forms as the user likes.
My current solution:
To make the code more readable and seperate functions i use namespaced objects. The first object holds general tasks and refers to the individual forms via a map which holds several arrays where each contains the id of a form and the reference to the object which holds all the functions which need to be performed especially for that kind of form.
The structure looks more or less similar to this:
var module_handler = {
_map : [], /* Map {reference_to_obj, id} */
init: function(){
var module = example_module; /* Predefined for this example */
this.create(module);
},
create: function(module) {
//Store reference to obj id in map
this._map.push([module,id = this.createID()]);
module.create(id);
},
createID: function(id) {
//Recursive function to find an available id
},
remove: function(id) {
//Remove from map
var idx = this._map.indexOf(id);
if(idx!=-1) this._map.splice(idx, 1);
//Remove from DOM
$('#'+id+'').remove();
}
}
var example_module = {
create: function(id) {
//Insert html
$('#'+id+' > .module_edit_inner').replaceWith("<some html>");
}
}
Now comes my question ;-)
Is the idea with the map needed?
I mean: Isn't there something more elegant like:
var moduleXYZ = new example_module(id)
which copies the object and refers only to that form.... Something more logical and making speed improvements?? The main issue is that right now i need to traverse the DOM each time if i call for example "example_module.create() or later on any other function. With this structure i cant refer to the form like with something like "this"???
Do you see any improvements at this point??? This would help me very much!!! Really i am just scared to go the wrong way now looking at all the stuff i will put on top of this ;-)
Thank You!

I think you're looking for prototype:
=========
function exampleModule(id)
{
this.id = id;
}
exampleModule.prototype.create = function()
{
}
=========
var module1 = new exampleModule(123);
module1.create();
var module2 = new exampleModule(456);
module2.create();