Detect data-part on widget

Question

I have a widget that allow me to pass a data-part. Based on if I informed a data-part to a instance of that widget, I want to show/hide something from the widget. So it is possible to detect on my widget viewmodel if the was specified something for a data-part?

Answer 1

The activate method of a widget's view model gets passed a settings object (this code is from the Durandal sample application):

ctor.prototype.activate = function(settings) {
    this.settings = settings;
};

Within the settings object, you can inspect the parent property which will give you the node that the widget was bound to:

<div data-bind="expander:{items:projects}"></div>

That should give you access to the data-part attribute on the node.

Answer 2

You could use the composition module's getParts method within the widget's attached event callback. See http://durandaljs.com/documentation/api#module/composition/method/getParts

// MyWidget viewmodel
define(['durandal/composition'], function (composition) {
    var widget = function() {
        var plugin = this;

        plugin.showSomething = function () {
            something.show();
        );

        // See http://durandaljs.com/documentation/Interacting-with-the-DOM    
        plugin.attached = function (view, parent) {
            // See http://durandaljs.com/documentation/api#module/composition/method/getParts
            var dataparts = composition.getParts(view);

            plugin.parts = {
                $partOne: $(dataparts.datapartnameone),
                $partTwo: $(dataparts.datapartnametwo)
            };

            if (plugin.parts.$partOne) {
                // An element with data-part="datapartnameone" was found in the host container
                plugin.showSomething();
            }
        };
    };

    return widget;
});

// Example host container

<div data-bind="MyWidget: {}">
    <span data-part="datapartnameone">My data-part</span>
</div>