/labs/architecture-examples/backbone.xmpp/js/lib/backbone.xmpp.node.js

//    Backbone XMPP PubSub Storage v0.3

//    (c) 2012 Yiorgis Gozadinos.
//    Backbone.xmpp is distributed under the MIT license.
//    http://github.com/ggozad/Backbone.xmpp


// A simple model/collection using **Backbone.xmpp.storage** and supporting XMPP
// notifications. Can be used to base your models upon.

(function ($, _, Backbone, Strophe, PubSubStorage) {

    // PubSub Item
    var PubSubItem = Backbone.Model.extend({

        sync: Backbone.xmppSync

    });

    // PubSub Items collection
    var PubSubNode = Backbone.Collection.extend({

        model: PubSubItem,
        node: null,
        sync: Backbone.xmppSync,

        // **initialize** expects the id of the node to be passed in `options`
        // as well as the Strophe connection.
        // If you do not know it ahead you should add the `node` attribute and
        // subscribe to the XMPP events manually.
        initialize: function (models, options) {
            options = options || {};
            if (options.id && options.connection) {
                this.setNode(options.id, options.connection, options.payloadFormat);
            }
        },

        setNode: function(id, connection, format) {
            if (this.node) {
                connection.PubSub.off('xmpp:pubsub:item-published:' + this.node.id, this.onItemPublished, this);
                connection.PubSub.off('xmpp:pubsub:item-deleted:' + this.node.id, this.onItemDeleted, this);
            }
            this.node = new PubSubStorage(id, connection, format);
            connection.PubSub.on('xmpp:pubsub:item-published:' + id, this.onItemPublished, this);
            connection.PubSub.on('xmpp:pubsub:item-deleted:' + id, this.onItemDeleted, this);
        },

        // **onItemPublished** is a subscriber to the `xmpp:pubsub:item-published` event.
        // When a model has been pushed to the server from a different client, it will be
        // received and added automatically to the collection, triggering an `add` event.
        // If the model already existed it will be updated triggering a `change` event.
        onItemPublished: function (item) {
            var payload = item.entry,
                self = this,
                d = $.Deferred(),
                existing,
                json;

            d.promise().done(function () {
                existing = self.get(item.id),
                json = self.node.parseItem(payload);
                if (existing) {
                    self.remove(existing, {silent: true});
                    self.add(existing, {at: 0, silent: true});
                    existing.set(json);
                } else {
                    json.id = item.id;
                    self.add(json, {at: 0});
                }
            });

            if (payload) {
                d.resolve();
            } else {
                this.node.connection.PubSub.items(this.node.id, {item_ids: [item.id]})
                    .done(function (res) {
                        payload = $('entry', res);
                        d.resolve();
                    });
            }
        },

        onItemDeleted: function (item) {
            item = this.get(item.id);
            if (item) {
                this.remove(item);
            }
        }

    });

    this.PubSubItem = PubSubItem;
    this.PubSubNode = PubSubNode;

})(this.jQuery, this._, this.Backbone, this.Strophe, this.PubSubStorage);