You'll see in the next sketches that the mechanism works by components sending messages to one another.
In MVC, you'll see the message flow is actually relatively simple.
In MVC, you'll see the message flow is actually relatively simple.
We can even simplify it further into:
- Model
- User Interface (UI)
- An event fires in the view
- The view sends an "event handler" message to the controller (the handler is associated with the event).
- The controller sends an "action" message to the model.
We have a tripler model (object). It has a value and can triple the value.
The purpose of the UI is to display the model, and to offer actions like button clicks to manipulate the model.
All is quiet at the moment.
The purpose of the UI is to display the model, and to offer actions like button clicks to manipulate the model.
All is quiet at the moment.
- Button is pressed which fires click event
- View sends message that is associated with event to controller.
- Controller recieves message and relays message "triple" to model.
The model would then triple its value (shown on next step).
The model received the triple message so has tripled its value from 5 to 15.
And the view has simply refreshed to display the updated value.
And the view has simply refreshed to display the updated value.