Embed Size (px)
Citation preview
1
Another group of Patterns
Architectural Patterns
2
Patterns
Pattern: A representation of a proven solution.
Problem
Applicable Forces
Solution
ConsequencesBenefits
3
Software Architecture
• Architecture is OVERLOADED– System architecture
– Application architecture
• Architecture for this presentation is
• The modules, processes, interconnections, and protocols which constitute the deployed software system.
• Different from the behavioral architecture which describes how the business classes execute the business processes.
4
Architecture Specification
• Document which defines in text and diagrams the design, flow and technologies of the design.
• Shows how persistence, communication, and behavior are to be implemented in the system.
5
Types of Patterns
• Lowest Level – Programming Patterns– Iterator, if, while
• Design Level – Design Patterns– Factory, builder, --- gang of 4
• Before Design – Architectural Patterns–Martin Fowler- presentation, domain, data
storage, environment
• Analysis Patterns – – used in requirements analysis
6
Architectural Layers - Patterns
–Presentation » interactions with the user – HTML, thick client, MVC,
web services
–Domain (Logic) » Business rules, validations, calculations,
verifications
–Data Storage » database
–Environmental» Session management, messaging
7
Presentation Architectural Patterns
• Presentation interactions with the user
• No Client
• Thick Client (rich client)
• Thin Client
8
Presentation Architectural Patterns
• Model View Controller
• Application Controller
• Input Controller– Page Controller
– Front Controller
• View Controller– Template View
– Transform View
– Two Step View
9
Model View Controller
Separation of Presentation (View/Controller) from Domain (Model)
Separation of View and Controller
Model – Domain object
View – Presentation object
Controller – Controller object to handle user request/response
10
Application Controller
A centralized point for handling screen navigation and flow of an application.
Application Controller – determines which type of input is needed or which screen.
Input Controller
View
Application Controller
Domain Layer
11
Application Controller
12
Application Controller
• A single point of control to change program flow and navigation
• May be in mediating layer between the presentation and the domain
• May be reusable across various presentations
• Testable outside the UI framework.
13
Front Controller
14
Page Controller
15
Front vs Page Controller
• Front Controller – Single point for adding behavior
– Can add behavior dynamically (filter pattern)
– Use with more complex applications
• Page Controller – Simple - Input controller per page
– Don’t put controller logic into scriplets – use separate classes
– More prone to duplicate code with this controller
16
Template View
17
Transform View
18
Template vs Transform vs Two Step
• Template View– Follows natural editing notions
– Supports non=programmer editors of HTML
– Needs discipline to avoid scriplets
• Transform View– Can test without server
– Works well with XML
• Two Step View– Easy to make global appearance changes
– Easy to support multiple appearances
– Complex
19
Example
20
Data Storage
• Need mechanisms to allow RDBMS to communicate in the OO world.
• With OO databases none of these patterns necessary.
• Useful even if non-OO language wants to communicate with RDBMS to make the DB flexible to change in type and to make the data representation protected.
21
Data Storage Patterns
• Table Data Gateway
• Row Data Gateway
• Active Record
• Data Mapper
• Structural Patterns– Foreign Key Mapping, Identify Field Association,
Table Mapping, Single Table Inheritance.
22
Table Data Gateway
23
Row Data Gateway
24
Row Data Gateway (2)
25
Active Record
26
Data Mapper
27
Distribution Patterns
• Remote Façade
• Data Transfer Object
28
Remote Facade
29
Data Transfer Object
30
Summary
• No one patterns is an end all
• Patterns are mechanisms to help decompose applications into reusable, maintainable, modules.
• The layers of development help to define the needed patterns
• No pattern is always correct -- fit the application.
31
Computing Degrees at FSU-Panama City
Math&ScienceBusiness
Math&EEGeneral
Information System Degrees Scientific Degrees
Management Information Systems (BS)
Information Studies (Web – BS,MS)
Computer Science (MS, Web-BS)
Computer Engineering (BS, Web-MS)
Systems Analysis IT Management Computer Consulting Application Programming
Web Development Network Management Information Systems Management of Information
Services Social Informatics Information and Communication
Technologies
Embedded Systems Image Processing Electronics and Electromagnetics Signals and Systems Communications Microprocessors Computer Architecture
Operating Systems Systems Programming Applications Programming Database Administration Systems Administration
. Degree Programs http://www.pc.fsu.edu/degreeplansheets/default.asp
. Advisor Jeanne Dexter – [email protected]
. Advisor Alan Stromberg [email protected] . Advisor Kamran Imen [email protected]
. Advisor Sara Stoecklin [email protected]
