Mumbai University > Computer engineering > Sem 7 > Software Architecture.

Marks: 10 M

Year: May14, Dec14, Dec13

An architectural pattern is a named collection of architectural design decisions that are applicable to a recurring design problem parameterized to account for different software development contexts in which that problem appears.

The three basic types of patterns used are:

1. State-logic- display: is an example of three-tier architecture, which is commonly used in business applications. There is a data store behind a business logic rule which is accessed by user interface components. Examples of state-logic-display are:
2. Business applications.
3. Multiplayer games.

4. Web-based applications.

5. Model-view-controller: is an architectural pattern which separates information (M), presentation (V) and user interaction(C). This pattern has dominance in graphical user interface.

6. Sense-compute-control: is typically used in structuring embedded control applications. This may range from simple device such as those found in kitchen appliances to sophisticated system used in automotive applications or robotic control.

Model-View-Controller

• The objective of this architectural pattern is separation between information (M), presentation (V) and user interaction(C).
• This pattern has been a dominant influence in the graphical user interfaces.
• When a model object value changes, a notification is sent to the view and to the controller. Thus, the view can update itself and the controller can modify the view if its logic requires.
• When handling input from the user the windowing system sends the user event to the controller.
• If a change is required, the controller updates the model object.

• The view component encapsulates the information chosen and necessary for graphical depiction of the information. The model component encapsulates the information used by the application. The controller component encapsulates the logic necessary to maintain consistency between the models and the view, and to handle inputs from the user as they relate to the depiction.
• It is applied to low level of program design. It is basically used in Java’s framework.

An example of MVC pattern can be seen in the world-wide-web.

i. Web resources correspond to the model objects.

ii. The browser corresponds to a view (the HTML rendering object

iii. The controller corresponds to the code that is part of the browser that responds to user input and which causes either interactions with a web server or modifies the browser’s display in some manner.

MVC has also inspired the development of other related architectural patterns, such as presentation abstraction-controller (PAC).