AngularJS, plotting markers on a LeafletJS map via Express, Node and MongoDB. How do you do it?

I have begun writing an app with AngularJS, LeafletJS, NodeJS, Express and MongoDB (MongoJS). The app features a navigation of categories and a large map. The categories list things like restaurants, parks, shops and businesses. Clicking on each one will need to update the map with markers showing where these type of places are.

I am trying to find a good example that shows how you can update a LeafletJS map via AngularJS, calling a REST API (express/nodeJs) to pull in coordinates from MongoDB and plot them on the map? Clicking on another category would then clear the map to show you where your local parks are etc.

I know this quite an open-ended question but I am trying to work out how to do this.

Thanks in advance!