How can I aggregate when I'm mapping in KnockoutJS? - json

Question

I'm working with KnockoutJS for a few days now and I have just faced with a simple problem that I cannot solve!
I have a model like this:
function Contact() {
var self = this;
self.name = ko.observable("");
self.phones = ko.observableArray([]);
self.faxes = ko.observableArray([]);
self.address = ko.observable("");
}
I have to call a service which will return repeatitive rows if each contact contains more that one phone or fax. e.g. :
{{"name":"Name1","phone":"1234","fax":"5654","address":"abc"},{{"name":"Name1","phone":"2323","fax":"8787","address":"abc"}}
I do a call like to server like this:
self.GetContacts = function () {
$.getJSON(self.queryUrl(),
function (data) {
if (data.results) {
self.contacts(ko.toJS(data.results));
}
});
There is no way to aggregate it on the serverside as it is an out-of-the-box tool and the only possible way is to aggregate it on the client side.
How can I aggregate them using my custom model, before binding them?

Answer 1

I would do something like that :
function aggragateContacts(data) {
var contacts = [];
ko.utils.arrayForEach(data, function (contactData) {
// looking an existing contact with the same name and address
var contact = ko.utils.arrayFirst(contacts, function (c) {
return c.name() == contactData.name && c.address() == contactData.address;
});
// otherwise create one
if (contact == null) {
contact = new Contact();
contact.name(contactData.name);
contact.address(contactData.address);
contacts.push(contact);
}
contact.phones.push(contactData.phone);
contact.fax.push(contactData.fax);
});
}
self.GetContacts = function () {
$.getJSON(self.queryUrl(),
function (data) {
if (data.results) {
self.contacts(aggragateContacts(ko.toJS(data.results)));
}
})
}