1. Arc Hydrology Data Model An Overview of the Modeling Process Kim Davis and Tim Whiteaker Center for Research in Water Resources University of Texas at Austin

2. Introduction • UML—What it is, How to read it • CASE tools—What they are, How they are used • Build the UML Model with CASE tools • Export to a Repository • Generate C++ code (make a .dll) • Create the schema in ArcInfo 8.0 • Do Cool, Fun Stuff…

3. UML • Unified Modeling Language • Graphical interface to computer languages • A higher evolution of flow-charts • The standard vocabulary for Object-Oriented Programming

4. How to read the UML • Classes (Objects) • Inheritance(Is a kind of…) • Subtypes(Is a specific type of…) • Composition (Is made of…) • Aggregation (Is loosely made of…)

5. How to read the UML • Classes(Objects) • Have Name • Have Attributes • Have Methods • May have Extensions • May have Interfaces • May participate in relationships

6. How to read the UML • Inheritance (Is a kind of…) • Alternatively called Generalization • Passes Attributes down the diagram tree • Passes Methods down the tree • Classes involved are called Parent and Child • Children are also called Sub-classes HydroPoint is a generalization of HydroStructure HydroStructure is akind of HydroPoint

7. More on Inheritance Of HydroStructure

8. How to read the UML • Subtypes(Is a specific type of…) • Used for different “flavors” of the same object • Have the EXACT same attributes • May have different default values for those attributes

9. How to read the UML • Composition(Is made of…) • Parent controls lifetime of Child • Implemented in database by use of key fields (Table Linking)

10. How to read the UML • Aggregation(Is loosely made of…) • Classes exist independently of each other • Implemented in database by use of key fields (Table Linking)

11. CASE tools—Intro • CAD=Computer Aided Drafting • CASE=Computer Aided Software Engineering • Well suited to modern programs (object oriented vs. menu driven) • Examples: Visio Enterprise/Professional, Rational ROSE, ObjectDomain

12. CASE tools—What they do • Began as flow chart converters • Automate programming tasks which are repetitive and subject to human error • Provide graphical format that eases transfer and comprehension of software architecture

13. CASE tools—Example Document Window “Table of Contents” Standard Shapes

14. Build the UML Model with CASE tools • Decide what objects to create • Brainstorm • Continuous refining • Determine what attributes they have • Enough to clearly define object • Minimum set to practice good modeling • Devise methods to give custom behaviors • Delineate relationships required

15. Generate C++ Code • Creates the objects you have designed so ArcInfo can use them • Implements the relationships and behaviors • Results in a .dll (dynamic link library) which contains the objects • Add custom code if desired

16. Create Schema in ArcInfo 8.0 • Creates empty tables in the geodatabase • Establishes relationships automatically • Looks to the .dll for information on custom classes • Allows user to choose which classes to instantiate • Allows last-minute editing of certain properties

17. Schema Creation • Allows user to choose which classes to instantiate • Allows last-minute editing of certain properties

18. Do Cool, Fun Stuff • Learn more through ESRI tutorials • UML - Visio Enterprise • C++ Code Generation • Schema Creation • Nifty Network Demo