Zombieapps

We, programmers, are responsible for the architecture of the software we build. But, usually, we let others decide how we structure our systems.

Our applications solve a problem following the rules of a domain. Our
main task is building a software model of that domain. That model is the core, the soul of our system, and we usually sell it to the highest bidder.

In this talk I'll talk about domain models. We will discuss the the part they should play in our application and how its presence benefits the practices that, we, XP practitioners, love.

This talk is in Spanish and was given during XPDay 2013 in Madrid.

Transcript

1. ZOMBIEAPPS
   Javier Acero
   jacegu
   jacegu
   javieracero.com
   

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3. 1
   2
   3
   BUSINESS LOGIC
   DATA SOURCES
   PRESENTATION
   

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4. 1
   2
   3
   Busine
   Logic
   

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5. Business Logic is a non-technical term
   generally used to describe the functional
   algorithms that handle information exchange
   between a database and a user interface.
   - Wikipedia
   

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6. Business Logic is a non-technical term
   generally used to describe the functional
   algorithms that handle information exchange
   between a database and a user interface.
   - Wikipedia
   oh boy...
   

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7. - Martin Fowler, Patterns of Enterprise Application Architecture
   Business Logic is the work the application
   needs to do for the domain it’s working with.
   

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8. CALCULATIONS VALIDATIONS
   CALLS TO EXTERNAL SYSTEMS
   +
   + =
   BUSINESS LOGIC
   

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9. SCRIPT
   TRANSACTION
   

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10. TRANSACTIONS
    busine logic a
    

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11. PROCEDURES
    modeled a
    def newPurchase()
    DB.insert();
    commit();
    end
    

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12. simple
    easy to understand
    works great with simple datasources
    makes transaction boundaries visible
    00
    {
    ADVANTAGES
    

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13. 00
    {duplicated code procedural code
    duplicated code procedural code
    duplicated code procedural code
    duplicated code procedural code
    ADVANTAGES
    DIS
    

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14. duplicated code
    get wo e a the a lication gro
    time
    

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15. MODULE
    TABLE
    

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16. OPERATIONS
    busine logic a
    TABLE ROWS
    on
    

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17. OBJECTS
    modeled a
    class Product {
    def purchase();
    recordSets();
    RECORD SETS
    &
    class RecordSet {
    

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18. avoids duplication better than a
    transaction script
    00
    {
    ADVANTAGES
    helps overcoming the relational - oo
    mismatch
    

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19. 00
    {
    ADVANTAGES
    DIS
    modeling limited by and tied to the
    data model
    mechanisms basic to OOP like
    polymorphism are not available
    

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20. MODEL
    DOMAIN
    

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21. OBJECT
    busine logic a
    BEHAVIOUR
    

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22. OBJECT GRAPHS
    modeled a
    Product
    Price
    Stock
    ProductService
    ProductRepository
    

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23. - Martin Fowler, Patterns of Enterprise Application Architecture
    The Object Oriented way of
    implementing business logic.
    

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24. ADVANTAGES
    - Martin Fowler, Patterns of Enterprise Application Architecture
    The Object Oriented way of
    implementing business logic.
    

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25. 00
    {the hardest to comprehend
    data sources get more complex
    overhead for simple business logic
    ADVANTAGES
    DIS
    

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26. effort to enhance
    complexity of the business logic
    domain model
    table module
    transaction script
    

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27. effort to enhance
    complexity of the business logic
    domain model
    table module
    transaction script
    7.42
    

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28. Programming
    What about...
    eXtreme
    

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29. OOP
    SOLID DESIGN PATTERNS REFACTORING
    

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30. UBIQUITOUS
    LANGUAGE
    

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31. .........F......
    ................
    .....TESTING.....
    ......F.........
    ....**...F..F...
    

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32. ANEMIC
    antipa ern
    DOMAIN
    MODEL
    

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33. antipa ern
    DOMAIN
    MODEL
    DRIVEN
    TABLE
    

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35. antipa ern
    DOMAIN
    MODEL
    CONNECTED
    

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37. DOMAIN MODEL
    BUILD
    Ho t ...
    A RICH
    

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38. BBBBRRRRR
    RAAAAIIILS
    

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39. Thank You
    

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40. QUESTIONS?
    

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41. The icons and images used in this
    presentation were found using Google and
    belong to their respective authors.
    The Database Slide was taken from
    @unclebob’s talk at Ruby Midwest 2011
    Credit
    

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42. Here is where I found them:
    Credit
    Spaghetti: http://goo.gl/KrGiL
    Zombie 1: http://goo.gl/mHiYe
    Zombie 2: http://goo.gl/hk8i0
    Zombie Apocalypse: http://goo.gl/7IIK6
    Tool: http://goo.gl/75Svb
    

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