Try to modularize a not so legacy Android App

Given at an internal company event.

This talk tells a story how I (and my team) tried to modularize a new Android App we developed for a customer.

Transcript

1. Try to modularize
   a not so legacy Android App
   

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2. Customer:
   "I want an App and a SDK"
   

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3. The obvious solution
   someProject/android someProject/sdk
   

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4. The obvious solution
   someProject/android someProject/sdk
   consumes
   

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5. The obvious solution - requirements
   someProject/android someProject/sdk
   consumes
   artifactory CI/CD
   

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6. The modularization solution
   someProject/android
   /app
   /sdk
   Benefits:
   ● No headache with artifactory and CI/CD
   ● Development of the SDK is "on the fly"
   ● … more?!
   

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7. Customer:
   "The SDK should contain feature
   A,B,C and X,Y,Z"
   

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8. The obvious solution
   someProject/android Packages:
   awesome/feature/a
   awesome/feature/b
   awesome/feature/c
   awesome/feature/x
   awesome/feature/y
   awesome/feature/z
   /sdk
   

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9. The modularization solution
   someProject/android
   /y
   /c
   /b
   /a
   /z
   /x
   /sdk
   Benefits:
   ● Each is decoupled of others
   ● Could be published independently
   ● Wrapper SDK provide still the full SDK
   ● app modules could pick only features which they require
   ● … more?!
   

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10. Customer:
    "We use Scandit for scanning barcodes.
    Here are the licenses.
    Uh - and maybe we will replace it later
    with XYZ"
    

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11. The obvious solution - Try to abstract it away
    someProject/android
    /app
    /build.gradle
    add licenses
    Implementation:
    awesome/scaninng/
    abstract.kt
    scanditImpl.kt
    

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12. The modularization solution
    someProject/android
    /app
    /build.gradle
    add licenses
    Implementation:
    awesome/scaninng/
    abstract.kt
    internal/scanditImpl.kt
    /scanning
    Benefits:
    ● Clear separation in our build files
    ● scanning module can be changed without touching /app
    ● … more?!
    

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13. Developer:
    "Our onboarding is so heavily.
    Let's extract it"
    

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14. The obvious solution
    someProject/android
    /onboarding
    /app
    

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15. The obvious solution
    someProject/android
    /onboarding
    /app
    HELP!
    I need some files* from /app
    * files like `layouts` or utility classes
    

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16. The obvious solution
    someProject/android
    /onboarding
    /app
    /resources
    /utils
    

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17. The obvious solution
    someProject/android
    /onboarding
    /app
    /resources
    /utils
    HELP!
    I need some files from /sdk
    

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18. The obvious solution
    someProject/android
    /onboarding
    /app
    /resources
    /a
    /sdk
    

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19. The obvious (and correct) solution
    someProject/android
    /onboarding
    /app
    /resources
    /a
    /sdk
    

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20. Audience:
    "Well, that looks weird and complicated"
    

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21. Speaker:
    "No it's not. It's like playing lego and
    pick only the correct bricks together"
    

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22. Q'nd A
    

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