Android MVP: safe use Context in Presenter

Question

In my app I work with ContentProvider and use LoaderManager.LoaderCallbacks.

Fragment (View)

Answer 1

Code like this

Loader loader = new ArticleCatalogLoader(context, categoryId);

leads to untestable code. You should avoid creating "business" objects in your code and let anyone else do it for you (any DI framework such as Dagger 2 would be a better option than handling it yourself)

Having said that, your problem is something that DI has solved a long time ago. Do you need a fresh new instance of any object? Use a Provider

A Provider is an object that "provides" instances of objects. So instead of having

Loader loader = new ArticleCatalogLoader(context, categoryId);

you will have

Loader loader = loaderProvider.get(categoryId);

So the only thing you need is something like this:

public class ArticleCatalogPresenter ... {
    ...
    private final Provider loaderProvider;

    public ArticleCatalogPresenter(Provider loaderProvider, ...) {
        this.loaderProvider = loaderProvider;
        ...
    }

    private Loader onCreateArticleCatalogLoader(Bundle args) {    
        int categoryId = args.getInt(CATEGORY_ID);
        Loader loader = loaderProvider.get(categoryId); // no context needed anymore!
        return loader;
    }

}