Force to ko.observable manually to notify subscribscription on page load

Question

I'm trying to trigger self.selectedNavigation subscription each time my page loads. I have tried the code below, but it is not working.

self.selectedNavigation = ko.observable(-1);
self.selectedNavigation.extend({ notify: 'always' });
self.selectedNavigation(self.navigations()[0].id());
self.selectedNavigation.valueHasMutated();

self.selectedNavigation.subscribe(function (newValue) {
    alert(newValue);
});

Is this even possible? if yes, how do I trigger it?

Answer 1

For a subscription to get notified for changes, it has to be registered before the actual change has occurred:

// first defining the observable
self.selectedNavigation = ko.observable(-1);

// subscribing for changes
self.selectedNavigation.subscribe(function(newValue) {
    alert(newValue);
});

// mutating value
self.selectedNavigation(1);

See Fiddle