EFL MVVM Notes

efl-mvvm.md

EFL MVVM

General MVVM notes

Views

• Usually just shows stuff on screen
• Consumes data from ViewModel
• Bind properties to the ViewModel
  • Two way binding
  • Data on the ViewModel is shown
  • Activations on the View are sent to the ViewModel

ViewModel

• Implement the properties and commands the View can bind to
• Notifies the View of state changes through events (IObservable)
• Coordinate View interaction with Models
• Can act as a "conversion layer" between the raw Model data and the View
  • For example, combining two Model properties

Model

• Non visual classes that encapsulate domain's data and business and validation lgic.

Data bindings

• A run-time decision to connect ViewModels to View
• View-first composition
  • App composed of Views
  • They connect to the ViewModels they depend on
  • The ViewModels do not have a dependency on the Views themselves
  • More natural way
• ViewModel-first composition
  • App composed of ViewModels
  • A service locates Views for a given ViewModel
• Views and ViewModels should be kept independent as much as possible
• BindingContext
  • Property of BindableObject

MVVM In EFL

Models

• Efl.Model.eo

  • Interface
  • Store named properties
  • Can have Efl.Objects as children
    • Allows complex hierarchies
  • Emits events
    • properties,changed - Properties become ready or changed values.
    • child,[added,removed] - Child handling

• Efl.Loop_Model

  • Implements Efl.Model
  • Uses Eo reflection to set properties
  • volatile_make as helper to auto unref childs

Views

• Efl.Ui.View.eo
  • Single model get/set property

ViewModels

• Efl.View_Model.eo
  • Extends Efl.Composite_Model
    • Extends Efl.Loop_Model
      • Extends Efl.Loop_Consumer
      • Implements Efl.Model
      • Method volatile_make
        • Registers this model to be deleted if their only ref is their parent's one.
    • Implements Efl.Ui.View
    • Property: Index