Question

Is there a more complicated example of knockout.js along the lines of Holla https://github.com/maccman/holla/commits/master/app ?

I would like to have a list/tree on a left pane that would populate a form on a right side pane.

Answer 1

Here’s a skeleton for a master/details app. You can see it live on this jsfiddle. In the JSFiddle, I simplified the code a bit, but it’s probably better to have a separate select function rather than using $parent.selectedItem directly. If you’re doing other stuff as well, you’ll want the var self = this; variable to use in functions where this may not be bound to the right object.

<table border="3" cellpadding="2">
    <tr>
        <th>Item list</th>
        <th>Details</th>
    </tr>
    <tr>
        <td class="list">
            <ul data-bind="foreach: items">
                <li data-bind="text: label, click: $parent.select"></li>
            </ul>
        </td>
        <td class="detail"  data-bind="with: selectedItem">
            <div>Item: <span data-bind="text: label"></span></div>
            <div>Price: <span data-bind="text: price"></span></div>
        </td>
    </tr>
</table>

and the javascript:

function Item(title, amnt) {
    var self = this;

    this.label = ko.observable(title);
    this.price = ko.observable(amnt);
}

var items = [ new Item('foo', 27.30), new Item('fruity foo', 30.12), new Item('foo bar', 12.34)];

function viewModel(list) {
    var self = this;

    this.items = ko.observableArray(list);

    this.selectedItem = ko.observable();

    // You could call $parent.selectedItem from the binding directly, but it's a bit of a hack
    this.select = function(item) {
        self.selectedItem(item);
    }
}

ko.applyBindings(new viewModel(items));