Post on 09-Feb-2016
description
Design MechanismsThe path to successful projects
Lars FredholmMagicIT
Bio
Lars Fredholm, System Enginer IBM, RSV, LANI, MSC, MagicIT AB C, Clipper, VO, SQL-Windows, VB/MTS, Java Rose Experience since 1993 (Rose 2.x)Today: Rational OOAD/Rose Certified Instructor, MCP Consulting in Rational’s Tools
Architectural Mechanisms?
The Architect Mind
What does it mean technically?
Architectural Mechanisms? Technical functionality that is needed
WindowNavigatio
n
Persistency
Broker/Transaction
Security
Master/Detail
Communication
Language/Errors
Legacy System/
Import/Export
Devices
Reporting
Stateless/ State
GUIConcurrency/Distribution
Architectural MechanismsThree Categories
Architectural Mechanism Categories– Analysis Mechanisms (conceptual)– Design Mechanisms (concrete)– Implementation Mechanisms (actual)
Exampel – Persistence => Database => Sybase
Architectural Mechanisms have Characteristics
Persistency– Granularity: 1 to 10 Kbytes per row– Volume: up to 200000 rows– Access frequency
• Create: 500 per day• Read: 2,000 access per hour• Update: 1,000 per day• Delete: 50 per day
Communication– Synchronicity– Message Size– Protocol
Parts in RUPregarding Design Mechanisms
Inception / Early Elaboration– Requirements (functional and supplementary)– Build Technical Prototypes– SAD, Software Architecture Document
Elaboration– Model Design Mechanisms– Design Guidelines– Use Case Realization
Construction– Code Templates
Inception PhaseMilestone: Can we do this project?
Functional Requirements– Use Case survey, System scope, Priority
Non functional Requirements– Technical Prototypes (prove concept)
Candidate Architecture– Architecture Mechanisms
Project Plan– Cost and schedule
Functional RequirementsUse Case Model Survey
CompanyProject
Week
Employee
Gives Early Abstractions - Analysis Classes
Use-Case Model
Map to Analysis ClassesAnalysis Classes are early Classes
Mapping Mechanisms and Analysis Classes
Analysis Class Analysis Mechanism(s)
WeekProject
Employee
Company
ProjectController
Persistency, Security
Persistency, Legacy Interface
Persistency, Legacy Interface
Transaction
Persistency, Security
Non Functional Requirements Supplementary Specifications
GUIDevicesEnvironmentStorageCommunicationPerformanceDistribution
SupplementarySpecifications
Technical PrototypesTechnical prototypes proves the choice of Architecture and reduces Risks early
Validate Mechanism with Prototype If a Prototype doesnt exist, build it!
– GUI applet, graphical applet– Report applet, scanner applet– Database applet, transactions applet– Object broker applet– External system applet, import/export applet– Stress applets – Security applets
Candidate ArchitectureSoftware Architecture Document
Describes the Architecture by examples Shows Architecture significant examples of:
– Use Cases– Realizations– Class Diagrams– Process Diagrams– Component Diagrams– Deployment Diagrams– Data Model
SADSoftware Architecture Document
The Candidate Architecture
Elaboration Phase Milestone: Have we managed all questions regarding the Systems architecture?
Design Mechanisms– Design Patterns to Reuse
• Tested & proved technical Prototypes– Design Guidelines
• Rules to follow when designing the System
Use Case Realization– Use Case Scenarios with Iteration and Class
Diagrams
Design Mechanisms: Design Patterns
Parameterized Collaboration of components that solves a general design problem
Iteration Diagrams– Objects & Messages, Dynamic view
VOPC (View of Participating Classes)– Class Diagram, Static view
Technical Prototype– Code snippets
Design Pattern
Design Mechanisms
Inheritance– Use Structural behavior from Super Class
Delegation– Use build-in behavior from Subsystem
Role Classes (templates)– Reuse same behavior as modeled in Role Classes
Design Mechanisms,Design Pattern Styles
Design Mechanisms,Rose Design Model
Business Services
<<layer>>
Data Services<<layer>>
Design Mechanisms
User Services<<layer>> Use Case
Realizations
Design Model
Design Mechanisms,Package Overview
Design Mechanisms,Technical Use Case Diagram
Persistency
<<mechanism>>
Distribution<<mechanism>>
Security<<mechanism>>
Imaging<<mechanism>>
Transaction<<mechanism>>
Mechanism Client
GUI Navigation<<mechanism>>
Security Mechanismby Inheritance
Security Mechanism, Iteration Diagram
: Business
Object : cls
Session : cls
SecurityClient
1: ObjectPerm(String, clsSession)
2: ObjectPerm(String, clsSession)
3: ObjectPerm(String, PermissionType, RecordStatus)
4: Check Security Bit
Get Permission rights for Resource:3 * 5 binary bits1=Select, 2=New, 3=Update, 4=Softdelete, 5=Harddelete
Check if permission exist
Security Mechanism, VOPC, View of Participating Classes
clsSession
ObjectPerm()
Operation ObjectPerm() returns Permission rights for specified Resource:3 * 5 binary bits1=Select, 2=New, 3=Update, 4=Softdelete, 5=Harddelete
clsSecurity
ObjectPerm()SetResource()
(from Security)
Mechanism Client
Business Object
ObjectPerm()
<<role>>
Security Mechanism, Code Examples
'Check Permissions for resource
Public Function ChkRights(Session as clsSession, Resource as Object, Permission as Integer) As Boolean
On Error GoTo Catche
Dim strPerm as String
Try:
strPerm = Resource.ObjectPerm(Session)
Select Case Permission
Case 1 'Check VIEW permissions_ blnOk = Mid(strPerm,1,1)
Case 2 'Check NEW permissions _ blnOk = Mid(strPerm,2,1)
Case 3 'Check UPDATE permissions _ blnOk = Mid(strPerm,3,1)
Case 4 'Check DELETE permissions _ blnOk = Mid(strPerm,4,1)
Case Else _ blnOk=False
End Select
ChkRights=blnOk
Exit Function
Catche:
Err.Raise Err.number, Err.description, Err.source, Err.helpFile
End Function
Imaging Mechanismby Delegation
Security Mechanism, Iteration Diagram
Client
subsystem : ImageView
1: ImageNew( )
2: ImageScan( )
3: ImageSaveAs( )
4: PageInsertScan( )
5: ImageSave(VT_BOOL)
Imaging Mechanism, VOPC, View of Participating Classes
ImageViewMechanism Client
ImageSevices
(from User Services)
<<subsystem>>
Transaction Mechanismby Role Classes
Transaction Mechanism, Iteration Diagram
role : Controller
: ObjectContextglobal :
AppServer
Client
Get Transaction Server Control ObjectContext
5: Error Exception
role : Business Object
Atomic SQL
6) Errors ROLLBACK
4) Successful COMMIT
2: GetObjectContext( )
ObjectContext 4: SetComplete( )6: SetAbort( )
3: ObjectSave()1: Transaction
Transaction Mechanism, VOPC, View of Participating Classes
ObjectContext
SetComplete()SetAbort()
(from Transaction Server)
AppServer
GetObjectContext()SafeRef()
(from Transaction Server)
Business Object(from Role Classes)
<<role>>
Controller
Transaction()
(from Role Classes)
<<role>>
Mechanism Client
Via Client ProxyGlobal
Business Object(from Role Classes)
<<role>>
Business Object
ObjectSave()
(from Role Classes)
<<role>>
Transaction Mechanism, Code snippets – Templates
'Operation on <<role>> Controller Class in Application Server
Public Function Transaction() As Boolean
On Error GoTo Catche
Dim objCtxObj As ObjectContext
Try:
'Get MTS context Object from Global AppServer
Set objCtxObj = GetObjectContext()
'Inform MTS of Transaction Completion
If Not objCtxObj Is Nothing Then objCtxObj.SetComplete
Exit Function
Catche:
'Inform MTS of Transaction Abortion
If Not objCtxObj Is Nothing Then objCtxObj.SetAbort
Err.Raise Err.number, Err.description, Err.source, Err.helpFile
End Function
Design GuidelinesHandbook for designers
The Communication Tool
Realization Package: Iteration Diagrams
– Dynamic ViewVOPC (View of Participating Classes)
– Class Diagram - Static view
Use Case Realization
Use-Case Model Design Model
Use Case Use-Case Realization
Realization,Package Overview
Realization,Use case Behavior distributed to classes
Åtgärd Skapa intäktsfel<<realization>>
Registrera skada<<realization>>
Hantera skada<<realization>>
Preparera intäktsfil
(from Användningsfal l)
<<realizes>>
Interndebiteringsunderlag
(from Användningsfal l)
<<realizes>>
Skapa kundfakturafil
(from Användningsfal l)
<<realizes>>
Use Case Realization, Realization with Design Mechanisms
Receptionist is a person working in the Reception with Customers.
Order is received from Customer by Receptionist. The Paper is Scanned and Customer information captured by the System.
Receive Order(from Användningsfal l)
Receptionist
(from Aktörer)
Use Case Realization, Realization with Design Mechanisms
Enter New Order is a part of the GUI Navigation Mechanism
Client
role : DetailPage
interface : iWindow
role : DetailPage
1: PrinterPrint( )3: ObjectNew( )6: ObjectView( )9: ObjectEdit( )
15: ObjectDelete( )18: RowNext( )
20: RowPrevious( )22: WindowClose( )
12: ObjectSave( )
5: ObjectNew( )8: ObjectView(Long)11: ObjectEdit(Long)
17: ObjectDelete(Long)14: ObjectSave( )
2: PrintForm4: ObjectNew(Boolean, iWindow)7: ObjectView(Boolean, iWindow)10: ObjectEdit(Boolean, iWindow)
16: ObjectDelete(iWindow)19: NextRow( )
21: PreviousRow( )23: Unload
13: ObjectSave( )
Use Case Realization, Realization with Design Mechanisms
GUI Navigation MechanismRole Class PageDetail cloned to frmOrder
: Receptionist
: frmOrder
1: ObjectNew( )MechanismGUI Navigation
Use Case Realization, Realization with Design Mechanisms
Imaging MechanismNo need to model deeper into SubsystemAlready fully modeled in Mechanisms
: Receptionist
: frmOrder : ImageView
1: ObjectNew( )MechanismGUI Navigation
2: Scan3: ImageNew( )Mechanism
Imaging
Use Case Realization, Realization with Design Mechanisms
Persistency Mechanism - clone clsOrder
: Receptionist
: frmOrder : ImageView : clsOrder
1: ObjectNew( )MechanismGUI Navigation
2: Scan3: ImageNew( )Mechanism
Imaging4: Enter Data
5: ObjectSave( )MechanismPersistency
6: ObjectNew(Recordset, clsSession, Long, String)
7: ObjectSave(Recordset, clsSession, Recordset, Boolean)
Use Case Realization, Realization with Design Mechanisms
All Mechanisms
: Receptionist
frmOrder : iWindow
: ImageView : clsOrder : OrderController
1: ObjectNew( )MechanismGUI Navigation
2: Scan3: ImageNew( )Mechanism
Imaging4: (Enter Data)
5: ObjectSave( )
MechanismPersistency / Distribution
6: RetreiveOrder( )
8: ObjectNew(Recordset, clsSession, Long, String)
MechanismTransaction
7: ObjectPerm(String, clsSession)MechanismSecurity
9: WindowClose( )
Use Case Realization, Long version
Without Mechanisms – a long long version : Receptionist
frmOrder : iWindow
: ImageView : clsOrder : clsOrderList : iMenu : frmOrder : OrderController
1: ObjectNew( )
5: Scan
9: (Enter Data)
10: ObjectSave( )
19: WindowClose( )
6: ImageNew( )
15: ObjectNew(Recordset, clsSession, Long, String)
14: ObjectPerm(String, clsSession)
11: ObjectSave( )
13: RetreiveOrder( )
17: ObjectSave(Recordset, clsSession, Recordset, Boolean)
18: Validate(Boolean, clsSession, Recordset, String, Variant)
16: Fetch(Recordset, clsSession, Long, String)
2: Init(clsApplication, iWindow)
12: Data( )
3: ObjectNew( )
7: ImageScan( )
8: ImageSaveAs( )
4: MenuDetailNew( )
20: MenuReset( )
Construction PhaseMilestone: Are we ready to install?
Is it Good Quality code?Are executables Stable and Tested? Is System documented and mantainable?Will User receive high usability? Is it inside timeframe (TTM)?
Code TemplatesCode snippets with variation points
Design Mechanisms gives reusable beaviour
Resusable beaviour are code segments with variation points (Roles)
Copy boring repeating codeFocus on essential programming tasksReusable code already testedCode Templates could be written
AutomationEnhanced by Design Mechanisms
Code Automation:Rose Code Generation (Stubs)Copy & Paste programmingCode WizardsTemplate ToolsRose Reversing Code (Round Trip)
SummaryUsing Design mechanisms
Inception– Anaysis Mechanisms identifies risks early
Elaboration– Design Mechanisms reduces risks early– Design Mechanisms accelerates modeling
Construction– Templates code reduces risks early– Templates code accelerates coding– Templates code increases quality of the code
Design MechanismsThe Vehicle to successful projects
www.magicIT.com
Lars Fredholm
Thank You!Thank You!