BIS07 Application Development - I

Business Information Systems Application Development An outline of computer programming Prithwis Mukerjee, Ph.D.

What shall we cover here
Languages and Environments
Computer Languages
Development Environments
Activities
What are the steps required to create an application
World of Objects
What and why ?
Business application design
Software development life cycle
Water fall method
Iterative Method
Rational Unified Process

From Desire to Deployment
I want the computer to print out “Hello Praxis” on the screen
Computer Prints out “Hello Praxis”
Hello Praxis Say “ Hello Praxis”

Structure of an “application” Database Application

What does an “application” do ? Database Read Write Print
“Process” Data
Manipulate
Modify Data

Same Task : Two Languages PRINT "Hello World" InputString$ = INLINE$("What is your name > ") InputString$ = InputString$ + " Welcome to Programming" PRINT InputString$ cout << "Hello World" << endl; cout << "What is your name ?" << endl; gets(InputString); strcat(InputString," Welcome to Programming"); cout << InputString << endl;

Which Language ?

What is a computer PROGRAM
A set of instructions that
A computer can “understand”
Correct syntax
That [ unless specified otherwise ] are executed sequentially
To generate a “desired” result
Correct semantics
PRINT "Hello World" InputString$ = INLINE$("What is your name > ") InputString$ = InputString$ + " Welcome to Programming" PRINT InputString$
Exceptions
CONDITIONALS
LOOPS

Conditional : IF – THEN – ELSE

BOTH : Conditional AND Loop FOR K = 1 TO 10 IF ( K < 5 ) THEN PRINT "I will not be naughty" K ELSE PRINT " I will not be naughty ... but i am getting tired " K END IF NEXT K

The Four Primary Tasks
Input – Output
Read and Write data
From Users
From databases
Manipulate Data
Assign values
Perform calculations or “operations”
Conditionals
IF – THEN – ELSE
Change the order of statements depending on certain conditions
LOOP
Repeat a statement a number of times using some CONDITIONAL statement

Compilation Process
Human being “write” a program in HIGH LEVEL LANGUAGE
C, C++, Basic
“closer” to natural languages like ENGLISH
Computers understand only a LOW LEVEL LANGUAGE
Which consists of sequences of ZERO and ONE ONLY
“Impossible” for a human being to write this code
Compilation is a process of converting the HLL to LLL
This is a tedious process which is best done by another program called a 'compiler'

Seven Steps to meeting expectations
A computer understands instructions given as binary code.
A human can delivery instructions in an English like language
These are the seven steps required to convert human instructions delivered in English to binary instructions that a computer can understand

Human to High Level Language
Choose a language to write the program
C, C++, Java
VB Script, Javascript
Programmer's task is to convert
From English
Say “hello praxis”
To C++ :
cout << “hello praxis”
Use an “Editor” to write the program in the language of your choice
Notepad ?
editor Say “ Hello Praxis”

High Level to Low Level Language
Same language, say C++, can be compiled by compilers from different vendors
Turbo C++
Microsoft C++
UDD C++
HLL like C++ is converted to a low level language which consists of binary code 0 and 1
The Compiler is a piece of software that automates this process
Compiler will also locate all syntax errors
Spelling
Punctuation
etc
editor compiler

Link with pre-built parts
Linker will also spot errors like undefined external requests
Not all the instructions needed for the complete execution are written by the programmer
Many parts of the program are provided by the vendor who has supplied the compiler in low level machine language
These have to be linked together with the part of the program written by the programmer
editor compiler linker

First Execution
The binary machine code is now ready for execution on the operating system
Windows XP / Vista
Unix / Linux
The first execution is expected to show up non-syntax errors :
Errors in logic
Errors in specifications
editor compiler linker runtime

Debugging : Locating & Fixing Errors
The debugging process generally leads all the way back to the editor where the program is altered to fix the problem.
All subsequent steps are done again
Until no more errors are found.
editor compiler linker runtime debugger

Deployed for Use
The final program is distributed on CDs or as downloads on the internet
Has to be packaged in an appropriate manner
With necessary runtime libraries
Pricing Decisions
Freeware ?
Single user license ?
Multiuser license ?
Hello Praxis editor compiler linker runtime debugger packaging

Integrated Development Environment
A single piece of software that does all the six functions
IDE is different from a language
For the same language there are different IDEs from different vendors
Some IDEs are better or more user friendly
Some IDEs are free, others have to bought
I ntegrated D evelopment E nvironment editor compiler linker runtime debugger packaging

A Free C++ IDE

XBasic IDE

Zoho Creator

Why ZOHO ?
Comparable in functionality to any IDE
Relational database management feature
Visual application development feature
Equivalent to Visual Basic + Oracle
Zero Cost
Nothing to buy or steal ( that is piracy)
No extra hardware required
Goes beyond any available IDE in terms
Rapid Deployment on the web : nothing else required !!
Basic security structures in place
So what is the catch ? What is missing
Very new product, not yet known in the market
No demonstrated capability in the corporate world
Wonderful tool to learn about application development

BIS07 Application Development - I

by Prithwis Mukerjee

Accessibility

Categories

Upload Details

Usage Rights

Statistics

BIS07 Application Development - I Presentation Transcript