model-view-controller: tips&tricks

Design Pattern

MVC July 17th, 2014

MVC

Agenda

● History ● MVC● Controller specifications● View specifications● Model specifications● Demo

History

Model View Controller (MVC) is one of the most quoted (and most misquoted) patterns around. It started as a framework developed by Trygve Reenskaug for the Smalltalk platform in the late 1970s. Since then it has played an influential role in most UI frameworks and in the thinking about UI design.

MVC● Controller sends commands to the model to update state.

Also sends commands to its associated view to change the appearance.

MVC● Controller sends commands to the model to update state.

Also sends commands to its associated view to change the appearance.

● A model notifies its controllers when there has been a change in its state. This notification allows the views to produce updated output.

MVC● Controller sends commands to the model to update state.

Also sends commands to its associated view to change the appearance.

● A model notifies its controllers when there has been a change in its state. This notification allows the views to produce updated output.

● A view requests information from the model that it needs for generating an output representation to the user.

MVCModel specifications:

● business logic

MVCModel specifications:

● business logic ● has knowledge about itself but does not know

about the controllers and views;

MVCModel specifications:

● business logic ● has knowledge about itself but does not know

about the controllers and views;● in some cases is a database manager or a set

of objects;

MVC Business logic - real-world business rules that determine how data can be created, displayed, stored, and changed.

Model

Model base types:- passive model- active model (basic type)

MVC

Model

ApiClient DataManager

update UI

MVC@property (readonly) DPManagerProvider *provider;

MVC@property (readonly) DPManagerProvider *provider;

#dynamic state

@property (readonly) NSString *email;

@property (readonly) NSString *password;

@property (readonly) NSString *messageText;

@property (readonly) BOOL canEdit;

MVC@property (readonly) DPManagerProvider *provider;

#dynamic state

@property (readonly) NSString *email;

@property (readonly) NSString *password;

@property (readonly) NSString *messageText;

@property (readonly) BOOL canEdit;

#static states@property (readonly) NSString *emailDefaultText;

@property (readonly) NSString *passwordDefaultText;

@property (readonly) NSString *title;

@property (readonly) NSString *loginTitle;

MVC@property (readonly) DPManagerProvider *provider;

#dynamic state

@property (readonly) NSString *email;

@property (readonly) NSString *password;

@property (readonly) NSString *messageText;

@property (readonly) BOOL canEdit;

#static states@property (readonly) NSString *emailDefaultText;

@property (readonly) NSString *passwordDefaultText;

@property (readonly) NSString *title;

@property (readonly) NSString *loginTitle;

#data access methods

- (void)login;

- (BOOL)shouldChangeEmailInRange:(NSRange)range

replacementText:(NSString *)text;

- (BOOL)shouldChangePasswordtInRange:(NSRange)range

replacementText:(NSString *)text;

MVCControllerModel

MVCControllerModel

● Notification

MVCControllerModel

● Notification● KVO

MVCControllerModel

● Notification● KVO● Delegate

MVCControllerModel

● Notification● KVO● Delegate● Binding

MVCController specifications:

● can transmit data

MVCController specifications:

● can transmit data ● can place Views on the screen

MVCController specifications:

● can transmit data ● can place Views on the screen ● can respond to user’s actions

MVCController specifications:

● can transmit data ● can place Views on the screen ● can respond to user’s actions ● can operate with several Views

MVCView specifications:

● can display data

MVCView specifications:

● can display data ● can, in some cases, have code that

implements some business logic

MVC

Controller

Model View

@ view;@ model;

MVC

Controller

Model View

View

MVC

Controller

Model

ViewController

View

MVC

Controller

Model View

View

Controller

MVC

Controller

ModelView

MVC

Controller

ModelView

View

Controller

Model@parameters

MVC

Controller

Model

Storyboard

Controller

Model @parameters

MVCAdditional materials:

● Msdn MVC

● MVC https://developer.apple.com

● Refactoring code

http://martinfowler.com/books/refactoring.html

● Steve McKinley “Perfect Code”

● Eric Freeman “Design Patterns”

Demo: dima.sai github - dsay