Object-Oriented Programming with NaturalX

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Object-Oriented Programming with NaturalX
m i n d c r o s s

• Presented by Rosanne Verteramo
• Sr. Training Consultant
• MindCross Training Consulting

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MindCross Training Consulting -
www.mindcross.com
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Overview

• In such a rapidly changing field as OOP, it is
  essential to not only keep up but to lead the
  way. This presentation will cover the basic
  concepts of object-oriented programming and the
  elements of object oriented design, including
  objects, classes, and methods. It will introduce
  NaturalX and show you how to do Object-oriented
  programming (OOP) using NaturalX and the Natural
  development environment on NT.

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Topics

• An Introduction to Object-Oriented Programming
  (OOP)
• The basic principles
• Object-oriented design
• Classes and methods
• OO Programming with NaturalX
• What is NaturalX?
• Component-oriented development with NaturalX

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Introduction to Object-Oriented Programming
m i n d c r o s s
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MindCross Training Consulting -
www.mindcross.com
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Object-Oriented Programming

• Why Object-oriented Programming (OOP)?
• It will quickly and easily lead to increased
  productivity and reliability due to reuse
• Reusable components
• Easy transition from existing languages
• Similar to other programming techniques
• Enables Enterprise Application Integraiton (EAI)

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Object-Oriented Programming

• Understanding the concepts.
• A new way of thinking
• A programming technique
• Oriented around objects and data
• Object-oriented languages do not force
  object-oriented programming

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The Basic Principles of OOP

• An analogy sending wine and cheese to a friend
  in another state

Friend
Wine and cheese
Me
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The Basic Principles of OOP

• An analogy sending wine and cheese to a friend
  in another state

Friend
Wine and cheese
Me
method
message
agent
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Elements of OOP - Objects

• Everything is an object
• A software bundle of related variables and
  methods a code block
• Used to model real world objects
• Two characteristics
• State - Maintained within variables / data
• Variables are known as properties
• Behavior - Implemented within methods / functions
• An object is an instance

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Elements of OOP - Objects

• Everything is an object (continued)
• Packaging properties/variables within the method
  of an object is known as encapsulation
• Exposing properties makes them publicly available
  to the user of the object

Object
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Elements of OOP - Objects

• Everything is an object (continued)
• Encapsulating variables/properties and methods
  within an object provides two primary benefits
• Modularity
• The source code for an object is written and
  maintained independently of other objects
• Promotes reusability
• Information hiding
• Modifications to the information will not affect
  other users of the object

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Elements of OOP - Messages

• Communication between objects is accomplished by
  passing messages
• Actions are produced in response to requests,
  called messages
• An object may accept a message, and in return
  will perform an action and return a value
• Additional information is passed to a method
  within an object as arguments or parameters

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Information Hiding Encapsulation

• As a user of a service being provided by an
  object, you only need to know the name of the
  messages that the object will accept
• Its not necessary to know how the actions
  performed in response to the request will be
  carried out
• The object is responsible for carrying it out the
  request

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Elements of OOP - Receivers

• Messages differ from traditional function calls
  in two very important respects
• In a message there is a designated receiver that
  accepts the message
• The interpretation of the message may be
  different, depending upon the receiver

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Elements off OOP - Classes

• A class is a blueprint that defines the
  properties and methods for that class
• Every object is an instance of a class
• The variables and methods will be common to all
  objects
• Behavior is associated with classes, not with
  individual instances
• All objects that are instances of a class use the
  same method in response to similar messages

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Elements off OOP - Classes

• Every objects state is independent of every
  other object related to that class
• For every instance of a class the system
  allocates enough memory for the object and all
  its data

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Classes and Instances

• An object is an instance of a class
• Class Square
• Instance Maggies_ green_ square

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Classes and Instances

• Class hierarchies
• Classes can be created from other classes
• Class Bike
• Class Mountain_Bike
• Mountain_Bike is considered a sub-class of Bike
• Bike is considered the superclass

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Elements of OO - Inheritance

• Classes are organized into a singly-rooted tree
  structure, inheritance hierarchy
• Relates to both data and/or behavior
• Everything from a higher level class is
  automatically applicable to lower levels in the
  hierarchy

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Classes and Instances

• Class hierarchies - inheritance hierarchy

Class dot
Class line
Class rectangle
Maggies green square
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Elements of OOP - Encapsulation

• The proper use of methods
• One must provide the intended user of a module
  with all the information needed to use the module
  correctly, and with nothing more

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The Basic Principles of OOP

• OOP is not simply features added to a programming
  language - - it is a new way of thinking
• The OOP views a program as a community of agents,
  termed objects
• Each object is responsible for a specific task
• An object is an instance of a class

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The Basic Principles of OOP

• Communication is accomplished by passing messages
• An object is an encapsulation of state (data
  values) and behavior (operations)
• Every object has its own memory
• The behavior of objects is dictated by the object
  class

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The Basic Principles of OOP

• Classes are organized into a tree structure
  called the inheritance hierarchy
• An object will exhibit its behavior by invoking a
  method (similar to executing a procedure) in
  response to a message
• The OOP view of computation is that an
  application is a conglomeration of interacting
  computing objects

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OO Programming with NaturalX
m i n d c r o s s
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MindCross Training Consulting -
www.mindcross.com
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What is NaturalX

• Software AGs technology for component-oriented
  development using Natural

Natural
Mainframe
Unix
Windows
Open VMS
AS/400
Database
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What is NaturalX

• Component-oriented development

Component
Component
Component
NaturalX
Visual Basic
Visual C
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What is NaturalX

• Component-oriented development

EntireX DCOM
EntireX DCOM
EntireX DCOM
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Natural Development Environment

• Natural Studios
• User-friendly GUI for development of procedural,
  event-driven, and component-based Natural
  applications
• Includes a Class Builder for developing NaturalX
  classes/components
• Automatically generates code and statements
  necessary for the NaturalX class module

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Natural Development Environment
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NaturalX Statements

• Define Class . . .
• Define Interface . . .
• Property . . .
• Method Is. . .

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NaturalX Commands

• Register
• Deregister

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Steps to Creating NaturalX Classes

• Using the Class Builder
• Create a new Class with name
• Create a new Interface with name
• Create methods with appropriate names
• Implement methods as subprograms
• Create properties with appropriate names
• Create Object data area
• Stow class with module name
• Register

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Steps to Creating NaturalX Classes
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Components of a NaturalX Class
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Components of a NaturalX Class
Class Name and ClassID (GUID)
Interface Name and Interface ID (IID)
Method Name
PDA
Properties
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NaturalX Structure for Classes

• Define Class . . .
• Define Interface . . .
• Property . . .
• End-Property
• Method . . .
• End-Method
• End-Interface
• End-Class

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NaturalX Syntax for Class objects

• Define Class xxxxxxxx
• Object using LDA
• Local using GUID_LDA
• ID GUID_Variable (from GUID_LDA)
• Interface InterfaceName
• ID Interface_ID (from GUID_LDA)
• Property PropertyVariable
• IS VariableName (link variable to property)
• End-Property
• Method MethodName
• IS SubprogramName
• Parameter Using PDA
• End-Method
• End-Interface
• End-Class
• End

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NaturalX Statements

• Create Object . . .
• Send Method . . .

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Calling NaturalX Components

• Declaration
• Define data local
• 1 ObjectName HANDLE of OBJECT
• End-Define
• Instantiation
• Create Object ObjectName of CLASS ClassName
• Giving NaturalError
• Invoking Methods
• SEND Method MethodName to Object ObjectName
• WITH Parameters

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Calling NaturalX Components

• SEND syntax
• SEND Method MethodName to Object ObjectName
• WITH Parameters
• RETURN ReturnValueField
• GIVING NaturalError
• Parameter options
• By Value Input parameters of the method
• By Reference Input and output parameters
• By Value Result Return value for the method

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Writing the Client Program
1 MyEmpl Handle of Object Create Object MyEmpl
Of Class 'DEMOCLASS Send Method 'GET_EMPL' To
Object MyEmpl WITH PID result
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Registering Classes with NaturalX

• Manual Register/Deregister
• Register ClassName LibraryName
• DeRegister ClassName LibraryName
• Automatic Registration using Natparms
• AUTOREGISTER

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Distributing Components

• DCOMCNFG
• Microsoft utility which specifies information
  needed for DCOM
• Location of COM object
• Permissions
• Runtime specifications
• On Server - define launch and access permissions
• On Client - define location of COM object

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Distributing Components

• DCOMCNFG.exe

Component on NT Server
Define location of component on client machine
Define security (launch and access privileges)
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Writing the Client Program
1 MyObject Handle of Object
Create Object MyObject Of Class
'EAS.EMPLOYEE'
Height MyObject.Height
MyObject.Height Height
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The Component Browser

• Means for Browsing all Components
• GUIDs
• Interfaces
• Properties
• Methods
• Type library is created for every NaturalX class
  as part of the Register process

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Summary

• OOP is a new way of thinking
• OOP involves the use of classes, objects,
  methods, and properties
• A class is a blueprint for a software module
• An object is an instance of a class
• A method represents the code within the class for
  behavior

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Summary

• Properties represent data
• Encapsulation allows reuse and promotes
  information and function hiding
• Inheritance hierarchy is the ability to create
  classes from other higher level classes
• NaturalX is a tool allowing you to create
  components using the Natural programming language

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Summary

• NaturalX uses classes, interfaces, and methods,
  and properties
• An interface is a group of methods
• A method is processed in NaturalX as a subprogram
• There is a one to one ratio between Natural
  methods and subprograms
• Properties are needed within NaturalX to make
  class data publicly available

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Summary

• Properties store their data within an Object data
  area
• There is one object data area per class in
  NaturalX
• GUIDs can be created automatically in NaturalX
  when stowing the class

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The End
Thank you, from MindCross Training
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