Part 1:


UML IS NOT A PROGRAMMING LANGUAGE____________________


UML Basic :  

 The Unified Modelling Language (UML) is the general purpose visual modeling language (A modelling language can be made up of pseudo-code, picture, diagram or long passages of description. ) that is used to specify, visualize, construct  and document the artifacts of software system. it captures decision and understanding  (Static and Dynamic behavior ) about the systems that must be constructed.

  - The static behavior defines the kinds of objects important to a system  and to implementation, as well as the relationships among the Object.  


  - The dynamic behavior defines the history of objects over time and the communications among objects to accomplish goals.


when to use UML:
a) UML as a SKETCH - use UML to make brief sketches to conve key points.
b) UML as a BLUEPRINT  - deatil definition
c) UML as a PROGRAMMING LANGUAGE - UML model to executable code


Advantage of using UML:
a) It is concise - made up of simple and straightforward notation.
b) It is comprehensive - describes all important aspect of system.
c) It is scalable - enough to  handle massive system modelling projects.
d) It  is standard - way to  represent


Different view of Model :
  There are number of ways, you can break the UML model diagram into views that capture your essence of system.

Logical view - 

Describes the abstract descriptions which is used to model what a system is made up of and how the parts interact with each other, this view include class, object, state machine, and interaction diagrams.

Process view - 

Describes the processes within your system and what must happen within your system. This view typically contains activity diagrams.

Development view - 

Describes how your system's parts are organized into modules and components.  This view typically contains package and component diagrams.

Physical view - 

Describes how the system's design, as described in the three previous views,  This view typically contains deployment diagrams.

Use case view -

Describes the functionality of the system being modeled from the perspective of the outside world. 

Part 2: 

Class Diagram : Logical view
    - 4 different ways of representing class in UML notation

 - Visibility :

-  State and attribute : 

- Relationship :

Multiplicity indicator

 - Dependencies :  A dependency between two classes declares that a class needs to know about another class to use objects of that class.

- Association  : An association describes discrete connections among objects or other instance in a system ( it  means that a class will actually contain the reference to an object or objects , of the other class in form of attribute. )

The Account class is optionally associated with zero or more objects of the AddressBook class; the AddressBook is also associated with one and only one Account

a) Navigatability :   

b) Association classes :
 

        AddressBook associated with an Account by virtue of the fact that it is associated with a  particular AddressBook

- Aggregation :  
                           It is kind of association that specifies a whole/part relationship between the aggregate (whole) and a component part. It is really just a stronger version of association and is used to indicate that a class actually owns but may share objects of another class. It is also called a “has a” relationship. 

- Composition : composition is an even stronger relationship than aggregation, although they work in very similar ways.

If the Blog is deleted, then its corresponding parts (BlogEntries) are also deleted. This is exactly what composition is all about modeling the internal parts that make up a class.


- Generalization / Inheritance :   
           Generalization relationship is a relationship in which one model element (the child) is based on another model element (the parent). Generalization relationships are used in class, component, deployment, and use case diagrams.

- Realization :  The realization relationship connects a model element, such as a class, to another model element, such as an interface, that supplies its behavioral specification but not its structure or implementation.
 realization relates two elements at different semantic level for ex:  an interface and class

- Constraint : 
  http://www.is.informatik.uni-duisburg.de/courses/mod_ws06/skript/uml-ocl.pdf


There are three types of constraint can be applied to class member using 
OCL (Object constain language).
a) Invariants : - 
b) Pre-conditons :-
c) Post-condition :-

-Reference Material :


a) Video for Class UML
b) http://www.holub.com/goodies/uml/