It seems that the way to connect entities on UML diagram is with ball-and-socket/lollipop notation. Each ball and socket pair should be listed with the interface implemented. However, as my project is in JavaScript there are no interfaces, so I am confused about what should replace it.
Am I right to use ball and socket notation, or is there some other notation I should use that would be more appropriate?
You connect your classes with associations. You can place role names and use the dot-notation to represent properties used to navigate between the classes.
From the specs. pp. 203:
... GH, end h is owned by Class G and end g is owned by Class H. Because the ends are class- owned, they are navigable. This is in a diagram where arrows are only shown for one-way navigable associations.
The lollipop-notation is used primarily to show interfaces between components (though you can also use it for classes).
I think that you can use the ball-and-socket/lollipop notation here just like an high level of abstraction on how your components are communicating. In fact here your are modelling your system in a certain abstraction level, so it is not the real one (obviously there must be consistency!).
See for example this UML Component Diagram Example.
