mardi 23 avril 2019

How to make object accessible from anywhere, without misusing static methods?

This question relates to a desktop application.

Something I'm always thinking about, is a way to be able to access an object that could be considered global, like if it is declared as static. But I always avoid this.

For example, in an application a User object (or something similar) is present very often. Imagine somewhere from the business logic a data model/repository is used, and you need the user ID to pass it as a parameter to the data layer so it can load the corresponding data for the user. Most times in web applications I see that information like a user ID is coming from a URL parameter, or HTTP post data, and is sent into a controller via its action method.

In desktop applications this is different, since all 'state' stays the same. Suppose a user object is constructed once on program startup, and of course stored now in memory somewhere. How do I access it from within another part of the application? It seems there are only two options:

  1. Using a static method on a general class that contains the user object, which returns it.
  2. Injecting the user object through the whole tree of classes that need the object.

I think both options are ugly and not optimal. Since I think it's a very common situation, what are best practises to keep a good structure?

Aucun commentaire:

Enregistrer un commentaire