Assuming you have multiple child views and don't want to introduce dependencies between shell and children it's probably best to use Durandal's event system for this. The shell view would become the publisher and the child views subscribers.
Check out http://dfiddle.github.io/dFiddle-1.2/#/event-aggregator/dFiddle for a working demo.
publisher.js
define(['durandal/app'], function (app) {
var message = ko.observable();
var canPublish = ko.computed(function () {
return message() ? true : false;
});
return {
message: message,
canPublish:canPublish,
publish: function () {
app.trigger('sample:event', message());
}
};
});
subscriber.js
define(['durandal/app'], function (app) {
return {
received: ko.observableArray([]),
subscription:ko.observable(),
subscribe: function () {
var sub = app.on('sample:event').then(function(message) {
this.received.push(message);
}, this);
this.subscription(sub);
},
unsubscribe: function () {
this.subscription().off();
this.subscription(null);
}
};
});
Other options that could be considered
- a shared module that returns a singleton with properties that should be shared between parent/childs. Drawback it needs to be defined as dependency in all parent/childs.
- one global e.g. myApp with properties... Drawback: exposing a global
