Kotlin for fullstack web/apps development

This talk covers the idea of having Kotlin to support in building multiple-component applications. With Kotlin's help, your Backend, Frontend, and Mobile all written in the same language, shares the same business model and domain objects, re-used the business rules and validations.
The talk also comes up with a sample code demonstration to understand how this could be realized.

Transcript

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2. About speaker
   Hello! I’m Toan
   Kotlin GDE, Android folk @Lazada
   https://toan.mobi
   toantran-ea
   toan_mobi
   

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3. Kotlin for fullstack web/apps development
   1. What is Kotlin? (2 mins
   )
   2. Why Kotlin? (5 mins
   )
   3. Kotlin multiple platform to power us (10 mins
   )
   4. Deep-dive into code to understand KMP (15 mins
   )
   5. Key-takeaways. (3 mins
   )
   

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4. What is Kotlin
   The Kotlin language project started in 2010 and soon went
   open-source
   

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5. Kotlin evolution
   v1.0: stable release
   v1.1: coroutines (experimental
   )
   v1.2: Kotlin multiple platforms/Kotlin native (experimental)
   v1.3: coroutine (stable
   )
   v1.4: Performance improvement
   

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6. GDG Location
   Why Kotlin?
   Expressiveness Safety
   Interoperability Structured
   concurrency
   

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7. class MainActivity : AppCompatActivity () {
   override fun onCreate(savedInstanceState: Bundle?) {
   ...
   fab.setOnClickListener { view ->
   Snackbar.make(view,
   "Hello ${name.capitalize()}",
   Snackbar.LENGTH_LONG).show()
   }
   fab.backgroundTintList = backgroundTintList
   }
   }
   Why Kotlin?
   

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8. class MainActivity : AppCompatActivity () {
   override fun onCreate(savedInstanceState: Bundle?) {
   ...
   fab.setOnClickListener { view ->
   Snackbar.make(view,
   "Hello ${name.capitalize()}",
   Snackbar.LENGTH_LONG).show()
   }
   fab.backgroundTintList = backgroundTintList
   }
   }
   Nullability in the
   type system
   Why Kotlin?
   

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9. class MainActivity : AppCompatActivity () {
   override fun onCreate(savedInstanceState: Bundle?) {
   ...
   fab.setOnClickListener { view ->
   Snackbar.make(view,
   "Hello ${name.capitalize()}",
   Snackbar.LENGTH_LONG).show()
   }
   fab.backgroundTintList = backgroundTintList
   }
   }
   Nullability in the
   type system
   Lambdas
   Why Kotlin?
   

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10. class MainActivity : AppCompatActivity () {
    override fun onCreate(savedInstanceState: Bundle?) {
    ...
    fab.setOnClickListener { view ->
    Snackbar.make(view,
    "Hello ${name.capitalize()}",
    Snackbar.LENGTH_LONG).show()
    }
    fab.backgroundTintList = backgroundTintList
    }
    }
    Nullability in the
    type system
    Lambdas
    Extension
    functions
    Why Kotlin?
    

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11. class MainActivity : AppCompatActivity () {
    override fun onCreate(savedInstanceState: Bundle?) {
    ...
    fab.setOnClickListener { view ->
    Snackbar.make(view,
    "Hello ${name.capitalize()}",
    Snackbar.LENGTH_LONG).show()
    }
    fab.backgroundTintList = backgroundTintList
    }
    }
    Nullability in the
    type system
    Lambdas
    Template
    expressions
    Extension
    functions
    Why Kotlin?
    

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12. class MainActivity : AppCompatActivity () {
    override fun onCreate(savedInstanceState: Bundle?) {
    ...
    fab.setOnClickListener { view ->
    Snackbar.make(view,
    "Hello ${name.capitalize()}",
    Snackbar.LENGTH_LONG).show()
    }
    fab.backgroundTintList = backgroundTintList
    }
    }
    Nullability in the
    type system
    Lambdas
    Template
    expressions
    Extension
    functions
    Property access
    syntax for getters
    and setters
    Why Kotlin?
    

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13. The major usage of Kotlin right now
    

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14. In my “ideal world”
    Cross-functional team model
    

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15. How Kotlin Multiple Platform could help?
    1. JVM Code
    2. JS Code
    3. Native Code
    4. Common Kotlin
    

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16. KMP - Common Kotlin
    1. The language, core libs, basic
    tools to serve all the platform.
    2. Rely on daily-task support
    tools like Http, serialization,
    and managing coroutines.
    

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17. Platform specific version of Kotlin
    1. Kotlin/JVM, Kotlin/JS,
    Kotlin/Native: Platform
    specific libs and tools.
    

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18. Structure of shared code
    

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19. Structure of shared code
    

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20. Structure of shared code
    

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21. Code demo - Project 1
    

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22. Code demo - Project 2
    

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23. Key takeaways
    1. Production ready? yes! (KotlinConf 2019: Kotlin in Space by Maxim
    Mazin)
    2. Not everything can be shared
    a. To share: Data, View Model, Validations, Utils, View Model, RPC,
    Common Libs
    b. Not to share: UI, Data storage
    

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24. Key takeaways
    3. Where to start? with sample
    a. Mobile KMP: Kotlin Conf app
    b. JS/JVM: git@github.com:kotlin-hands-on/jvm-js-fullstack.git
    c. Another one:
    git@github.com:Kotlin/kotlin-full-stack-application-demo.git
    4. Start with step-by-step guide: here
    

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25. Thank you
    

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