Architecture Recovery Of Web Applications

1
Architecture Recovery Of Web Applications
Ahmed.Hassan_at_uWaterloo.ca Software Architecture
Group University of Waterloo CANADA
2
Traditional Software Visualization

• LINUX

3
(No Transcript)
4
Visualization of Web Applications
5
Example of a Web Application

• Island Hopper News
• A sample web app. from MS

6
(No Transcript)
7
(No Transcript)
8
Web Application as a 3-tiered system
9
Web Applications

• Online in 60-90 days, Innovate at Web Speed,
  Change on a Dime..Asera Inc.
• Zero to Portal _at_ Web Speed..Oracle

10
SE Challenges for Web Apps?

• The speed of development
• The speed of evolution
• The different sets of concerns
• The expectations of the user
• The origins of the web

11
(No Transcript)
12
Introduction to ASP

• Simple html file (foo.html)
• lthtmlgt
• Welcome to CNN.COM
• lt/htmlgt
• ASP file (foo.asp)
• lthtmlgt
• Welcome to lt Write(CNN.COM) gt
• lt/htmlgt

13
Introduction to ASP

• Interesting asp file (foo2.asp)
• lthtmlgt
• Welcome to lt Write(Server.name) gt
• lt/htmlgt

14
Introduction to ASP

• ASP files are preprocessed by the web server
• ASP files access web server built in objects or
  distributed objects (COM/DCOM/COM/CORBA)
• ASP files can access databases too

15
Introduction to ASP
file.asp
file.html
Web Server Pre-processor
COM/ CORBA Objects
Data Tables
Data Flow
16
DEMO

• Visualization of the sample web application

17
How to visualize web applications?
18
Structure of an ASP Page
ASP Page
Client Scripts
Server Scripts
HTML
JScript
Perl
VBScript
VBScript
JavaScript
19
Generating the info to visualize
ASP Page
HTML Extractor
DB Access Extractor
ASP Code
ASP Extractor
HTML Facts
ASP Facts
Data Facts
20
First Attempt - Visualization
21
Generating Views for Web App.
FACTBASE
HTML Facts
ASP Facts
Data Facts
Source Code Facts
Binary Facts
Contain.
Grok
Layout
Viewer
22
Visualization
23
Visualization
24
Conclusion

• Web Apps developers face different challenges
  than Traditional Soft
• Visualization of Web Apps using our current tools
  is possible
• Large Web Apps have been visualized

25
Revealing some of the magic --- The hidden track!
26
Generating Views for Web App.
FACTBASE
HTML Facts
ASP Facts
Data Facts
Source Code Facts
Binary Facts
Contain.
Grok
Layout
Viewer
27
The Web App Domain Model
Component Subsystem
ASP, Database, DLL, COM Object, etc.
Java, JavaScript, VBScript, C, C, etc.
28
Entity Level Schema for JavaScript
29
Entity Level Schema for VBScript
30
Common Entity Level Schema for Object Based
Languages
31
Component Level Schema for Web Applications
32
Architecture Level Schema
33
Conclusion

• A Web App is the legacy application of the future
• A tool is built to visualize Web Apps and gain a
  better understanding of them
• A scalable framework is presented to study Web
  Apps
• Dynamic Static views are needed to understand
  Web Apps

34
Every day it becomes clear that the Net (Web) is
taking its place alongside the other great
transformational technologies that first
challenged, and then fundamentally changed, the
way things are done in the world, Lou Gestner,
CEO of IBM Corp.
35
A Taxonomy for Web Applications
36
Web App. Vs. Traditional App.

• Technical properties of Web App.
• Concerned with data tables, distributed objects
  and multimedia objects instead of variables,
  procedures and simple objects
• Heavy use of scripting to combine components
  together
• Implemented using multiple languages

37
Web App. Vs. Traditional App.

• Non Technical properties of Web App
• Shorter development time expected
• Lower costs expected too!
• Average employment length just over 1 year!!