Angular – Refreshing a Route with Parameters
Angular routing is pretty nifty. Going into how it works is beyond the scope of this post 
(and there’s plenty of resources out there doing just that), but suffice it to say if you’re working on an Angular application, you’re using Angular’s routing.
One of the things Angular’s routing does to increase performance is reusing a Component for a route that has already been instantiated. Say you have a Component, “MyComponent”, tied to a route, “/MyPath”. “MyComponent” isn’t created until the user actually navigates to the “/MyPath” route. That makes perfect sense – why instantiate a component that doesn’t need to be used yet? What’s interesting about this design, though, is how parameters factor into it. Let’s say you add a parameter to your “/MyPath” route, making the route “/MyPath/:id”. The first time the user navigates to some version of this route, let’s say “/MyPath/1”, “MyComponent” will be instantiated (with the id parameter set to 1). Then if, without leaving that route, the user changes only the parameter – for example, there’s a link in the component to go to “/MyPath/2”, “MyComponent” will not be recreated. In fact, if not handled correctly, to the user nothing will have changed. It will still look like they’re seeing the “/MyPath/1” version of “MyComponent”. Read more
When working with Angular Routing, it’s very useful to be able to respond to routing events – the most obvious and useful being when the route changes. In AngularJS this was accomplished with by attaching a callback function to one the “$routeChange” events on the $scope. In Angular the concept is similar but has some key (and in my opinion, useful) differences.