I'm very new to MVP and can't seem to grasp this concept.
Basically I have an activity which has an onClick which displays a DialogFragment. The activity does what it needs to do with MVP. The DialogFragment does too. However they are fully independent with regards to linking to each other which is posing a problem for me. When the DialogFragment chain is finished doing what it needs to do, the presenter on this layer holds the data to update the view on the Activity layer. I want the presenter in the DialogFragment layer to give the data to the presenter in the Activity layer who can easily let their view know as it's already linked up nicely.
I've thought of interfaces, read about eventBus (I know nothing about this so be kind).
There must be a specific way of achieving this because it must be a common task, I know I'm going to be doing it a few times in this application.
Your model is the data source in MVP. Don't know if I got your case properly or not but the model is responsible for providing data to the presenters.
So generally, your other presenter should be accessing the data it needs from the model. Your first presenter can ask the model to do insertions or updations etc required as per the business logic.
Once the alterations have been done by the model, your second presenter can access the data by asking for it from the model.
Hope, I made that out clearly.