Servers ❤️ Kotlin

A practical introduction of building an In App Purchase verification server backend with Kotlin using Ktor from JetBrains.

Transcript

1. Servers ❤ Kotlin
   Ryan Harter
   @rharter
   

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2. Ktor
   

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3. Ktor
   Easy to use, fun and asynchronous.
   

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4. Ktor
   Easy to use, fun and asynchronous.
   Composable, DSL based web services in Kotlin
   

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5. Ktor
   Application
   

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6. Ktor
   Application
   Jetty
   Netty
   Tomcat
   Servlet
   

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7. Ktor
   Application
   Feature
   Feature
   Feature
   Feature
   Servlet
   

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8. Ktor
   Application
   Feature
   Feature
   Feature
   Feature
   Routing
   HTML Templates
   Serialization
   Authentication
   Servlet
   

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9. Ktor
   

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10. Ktor
    Verify
    

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11. Ktor
    Verify
    Admin
    

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12. call.respond("Hello World")
    post("/verify") {
    routing {
    fun Application.verify() {
    }
    }
    }
    

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13. call.respond("Hello World")
    post("/verify") {
    routing {
    fun Application.verify() {
    }
    }
    }
    

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14. call.respond("Hello World")
    post("/verify") {
    routing {
    fun Application.verify() {
    }
    }
    }
    

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15. call.respond("Hello World")
    post("/verify") {
    routing {
    fun Application.verify() {
    }
    }
    }
    

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16. call.respond("Hello World")
    post("/verify") {
    routing {
    fun Application.verify() {
    }
    }
    }
    

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17. → curl -X POST -d '' http://localhost:8080/verify
    

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18. → curl -X POST -d '' http://localhost:8080/verify
    Hello World
    

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19. Typed Responses
    

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20. call.respond("Hello World")
    post("/verify") {
    routing {
    fun Application.verify() {
    }
    }
    }
    

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21. call.respond(Response(status = "OK"))
    post("/verify") {
    routing {
    fun Application.verify() {
    }
    }
    }
    data class Response(val status: String)
    

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22. → curl -X POST -d '' http://localhost:8080/verify
    

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23. → curl -X POST -d '' http://localhost:8080/verify
    →
    

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24. call.respond(Response(status = "OK"))
    post("/verify") {
    routing {
    fun Application.verify() {
    }
    }
    }
    data class Response(val status: String)
    

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25. call.respond(Response(status = "OK"))
    post("/verify") {
    routing {
    fun Application.verify() {
    }
    }
    }
    data class Response(val status: String)
    install(StatusPages)
    

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26. call.respond(Response(status = "OK"))
    post("/verify") {
    routing {
    fun Application.verify() {
    }
    }
    }
    data class Response(val status: String)
    install(StatusPages) {
    }
    exception { e ->
    }
    

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27. call.respond(Response(status = "OK"))
    post("/verify") {
    routing {
    fun Application.verify() {
    }
    }
    }
    data class Response(val status: String)
    install(StatusPages) {
    }
    exception { e ->
    call.respondText(e.localizedMessage,
    ContentType.Text.Plain, HttpStatusCode.InternalServerError)
    }
    

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28. call.respond(Response(status = "OK"))
    post("/verify") {
    routing {
    fun Application.verify() {
    }
    }
    }
    data class Response(val status: String)
    install(StatusPages) {
    }
    exception { e ->
    call.respondText(e.localizedMessage,
    ContentType.Text.Plain, HttpStatusCode.InternalServerError)
    }
    

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29. → curl -X POST -d '' http://localhost:8080/verify
    

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30. → curl -X POST -d '' http://localhost:8080/verify
    Cannot transform this request's content to class com.ryanharter.example.Response
    

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31. call.respond(Response(status = "OK"))
    post("/verify") {
    routing {
    fun Application.verify() {
    }
    }
    }
    data class Response(val status: String)
    install(StatusPages) {
    }
    exception { e ->
    call.respondText(e.localizedMessage,
    ContentType.Text.Plain, HttpStatusCode.InternalServerError)
    }
    

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32. install(StatusPages) { }1
    call.respond(Response(status = "OK"))
    post("/verify") {
    routing {
    fun Application.verify() {
    }
    }
    }
    data class Response(val status: String)
    ...
    

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33. call.respond(Response(status = "OK"))
    post("/verify") {
    routing {
    fun Application.verify() {
    }
    }
    }
    data class Response(val status: String)
    install(ContentNegotiation)
    ≈
    install(StatusPages) { }1
    ...
    ≈
    

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34. call.respond(Response(status = "OK"))
    post("/verify") {
    routing {
    fun Application.verify() {
    }
    }
    }
    data class Response(val status: String)
    install(ContentNegotiation)
    ≈
    install(StatusPages) { }1
    ...
    ≈
    {
    }2
    

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35. call.respond(Response(status = "OK"))
    post("/verify") {
    routing {
    fun Application.verify() {
    }
    }
    }
    data class Response(val status: String)
    install(ContentNegotiation)
    ≈
    install(StatusPages) { }1
    ...
    ≈
    {
    }2
    moshi()
    ≈
    ≈
    

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36. call.respond(Response(status = "OK"))
    post("/verify") {
    routing {
    fun Application.verify() {
    }
    }
    }
    data class Response(val status: String)
    install(ContentNegotiation)
    ≈
    install(StatusPages) { }1
    ...
    ≈
    {
    }2
    moshi()
    ≈
    ≈
    @JsonClass(generateAdapter = true)
    

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37. call.respond(Response(status = "OK"))
    post("/verify") {
    routing {
    fun Application.verify() {
    }
    }
    }
    data class Response(val status: String)
    install(ContentNegotiation)
    install(StatusPages) { }1
    ...
    {
    }2
    moshi()
    @JsonClass(generateAdapter = true)
    

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38. → curl -X POST -d '' http://localhost:8080/verify
    

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39. → curl -X POST -d '' http://localhost:8080/verify
    {"status":"OK"}
    

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40. call.respond(Response(status = "OK"))
    post("/verify") {
    routing {
    fun Application.verify() {
    }
    }
    }
    data class Response(val status: String)
    install(ContentNegotiation)
    install(StatusPages) { }1
    ...
    {
    }2
    moshi()
    @JsonClass(generateAdapter = true)
    

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41. call.respond(Response(status = "OK"))
    post("/verify") {
    routing {
    fun Application.verify() {
    }
    }
    }
    data class Response(val status: String)
    install(ContentNegotiation)
    install(StatusPages) { }1
    ...
    { }2
    @JsonClass(generateAdapter = true)
    ...
    

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42. Typed Requests
    

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43. View Slide

44. View Slide

45. call.respond(Response(status = "OK"))
    post("/verify") {
    routing {
    fun Application.verify() {
    }
    }
    }
    data class Response(val status: String)
    install(ContentNegotiation)
    install(StatusPages) { }1
    ...
    { }2
    @JsonClass(generateAdapter = true)
    ...
    

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46. call.respond(Response(status = "OK"))
    post("/verify") {
    routing {
    fun Application.verify() {
    }
    }
    }
    data class Response(val status: String)
    install(ContentNegotiation)
    install(StatusPages) { }1
    ...
    { }2
    @JsonClass(generateAdapter = true)
    ...
    ≈
    ≈
    ≈
    ≈
    @JsonClass(generateAdapter = true)
    data class Request(
    val userId: String,
    val packageName: String,
    val productId: String,
    val token: String
    )b
    

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47. call.respond(Response(status = "OK"))
    post("/verify") {
    routing {
    fun Application.verify() {
    }
    }
    }
    data class Response(val status: String)
    install(ContentNegotiation)
    install(StatusPages) { }1
    ...
    { }2
    @JsonClass(generateAdapter = true)
    ...
    @JsonClass(generateAdapter = true)
    data class Request(
    val userId: String,
    val packageName: String,
    val productId: String,
    val token: String
    )b
    ≈
    ≈
    ≈
    bird
    

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48. @JsonClass(generateAdapter = true)
    data class Request(
    val userId: String,
    val packageName: String,
    val productId: String,
    val token: String
    )b
    post("/verify") {
    routing {
    fun Application.verify() {
    }
    }
    }
    data class Response(val status: String)
    install(ContentNegotiation)
    install(StatusPages) { }1
    ...
    { }2
    @JsonClass(generateAdapter = true)
    ...
    ≈
    ≈
    ≈
    bird
    

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49. @JsonClass(generateAdapter = true)
    data class Request(
    val userId: String,
    val packageName: String,
    val productId: String,
    val token: String
    )b
    post("/verify") {
    routing {
    fun Application.verify() {
    }
    }
    }
    data class Response(val status: String)
    install(ContentNegotiation)
    install(StatusPages) { }1
    ...
    { }2
    @JsonClass(generateAdapter = true)
    ...
    ≈
    ≈
    ≈
    val request = call.receive()
    ≈
    ≈
    bird
    

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50. @JsonClass(generateAdapter = true)
    data class Request(
    val userId: String,
    val packageName: String,
    val productId: String,
    val token: String
    )b
    post("/verify") {
    routing {
    fun Application.verify() {
    }
    }
    }
    data class Response(val status: String)
    install(ContentNegotiation)
    install(StatusPages) { }1
    ...
    { }2
    @JsonClass(generateAdapter = true)
    ...
    ≈
    ≈
    ≈
    val request = call.receive()
    ≈
    ≈
    call.respond(request)
    bird
    

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51. @JsonClass(generateAdapter = true)
    data class Request(
    val userId: String,
    val packageName: String,
    val productId: String,
    val token: String
    )b
    post("/verify") {
    routing {
    fun Application.verify() {
    }
    }
    }
    data class Response(val status: String)
    install(ContentNegotiation)
    install(StatusPages) { }1
    ...
    { }2
    @JsonClass(generateAdapter = true)
    ...
    val request = call.receive()
    call.respond(request)
    

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52. →
    

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53. → cat << EOF >> /tmp/request.json
    

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54. → cat << EOF >> /tmp/request.json
    > {
    > "userId": "rharter",
    > "packageName": "com.pixite.pigment",
    > "productId": "com.pixite.pigment.subscription.monthly_t",
    > "token": “fpljlfogiejllhkebmjkpndm.AO-Oy5r83Kzef5afyMfL0suZM11l76cp_WdnWgOz...
    > }
    > EOF
    →
    

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55. →
    

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56. → curl -X POST —H "Content-Type: application/json" -d @/tmp/request.json \
    http://localhost:8080/verify
    

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57. → curl -X POST -H "Content-Type: application/json" -d @/tmp/request.json \
    http://localhost:8080/verify
    {“userId”:”rharter","packageName":"com.pixite.pigment","productId":"com.pixite.pig
    ment.subscription.monthly_t","token":"fpljlfogiejllhkebmjkpndm.AO-
    J1Oy5r83Kzef5afyMfL0suZM11l76cp_WdnWgOz..."}
    

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58. @JsonClass(generateAdapter = true)
    data class Request(
    val userId: String,
    val packageName: String,
    val productId: String,
    val token: String
    )b
    post("/verify") {
    routing {
    fun Application.verify() {
    }
    }
    }
    data class Response(val status: String)
    install(ContentNegotiation)
    install(StatusPages) { }1
    ...
    { }2
    @JsonClass(generateAdapter = true)
    ...
    val request = call.receive()
    call.respond(request)
    

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59. @JsonClass(generateAdapter = true)
    data class Request(
    val userId: String,
    val packageName: String,
    val productId: String,
    val token: String
    )b
    post("/verify") {
    routing {
    fun Application.verify() {
    }
    }
    }
    install(ContentNegotiation)
    install(StatusPages) { }1
    ...
    { }2
    ...
    val request = call.receive()
    call.respond(request)
    ???
    

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60. External Components
    

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61. @JsonClass(generateAdapter = true)
    data class Request(
    val userId: String,
    val packageName: String,
    val productId: String,
    val token: String
    )b
    post("/verify") {
    routing {
    fun Application.verify() {
    }
    }
    }
    install(ContentNegotiation)
    install(StatusPages) { }1
    ...
    { }2
    ...
    val request = call.receive()
    call.respond(request)
    ???
    

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62. @JsonClass(generateAdapter = true)
    data class Request(
    val userId: String,
    val packageName: String,
    val productId: String,
    val token: String
    )b
    post("/verify") {
    routing {
    fun Application.verify() {
    }
    }
    }
    install(ContentNegotiation)
    install(StatusPages) { }1
    ...
    { }2
    ...
    val request = call.receive()
    call.respond(request)
    // Find valid subscription in db or remotely
    ≈
    ≈
    

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63. @JsonClass(generateAdapter = true)
    data class Request(
    val userId: String,
    val packageName: String,
    val productId: String,
    val token: String
    )b
    post("/verify") {
    routing {
    fun Application.verify() {
    }
    }
    }
    install(ContentNegotiation)
    install(StatusPages) { }1
    ...
    { }2
    ...
    val request = call.receive()
    // Find valid subscription in db or remotely
    // Save to database
    ≈
    ≈
    

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64. // Return subscription or 404
    @JsonClass(generateAdapter = true)
    data class Request(
    val userId: String,
    val packageName: String,
    val productId: String,
    val token: String
    )b
    post("/verify") {
    routing {
    fun Application.verify() {
    }
    }
    }
    install(ContentNegotiation)
    install(StatusPages) { }1
    ...
    { }2
    ...
    val request = call.receive()
    // Find valid subscription in db or remotely
    // Save to database
    ≈
    ≈
    

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65. interface Api {
    suspend fun findSubscription(userId: String,
    packageName: String,
    productId: String,
    token: String): Subscription?
    }
    

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66. class PlayStore(serviceAccountFile: InputStream) : Store {
    private val publisher: AndroidPublisher by lazy {...}
    suspend fun findSubscription(userId: String,
    packageName: String,
    productId: String,
    token: String): Subscription? = coroutineScope {
    val response = async {
    publisher.purchases()
    .subscriptions()
    .get(packageName, productId, token)
    .execute()
    }
    response.await().asSubscription(ownerId, token)
    }
    }
    

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67. class PlayStore(serviceAccountFile: InputStream) : Store {
    private val publisher: AndroidPublisher by lazy {...}
    suspend fun findSubscription(userId: String,
    packageName: String,
    productId: String,
    token: String): Subscription? = coroutineScope {
    val response = async {
    publisher.purchases()
    .subscriptions()
    .get(packageName, productId, token)
    .execute()
    }
    response.await().asSubscription(ownerId, token)
    }
    }
    class top
    class bottom
    

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68. class PlayStore(serviceAccountFile: InputStream) : Store {
    private val publisher: AndroidPublisher by lazy {...}
    suspend fun findSubscription(userId: String,
    packageName: String,
    productId: String,
    token: String): Subscription? = coroutineScope {
    val response = async {
    publisher.purchases()
    .subscriptions()
    .get(packageName, productId, token)
    .execute()
    }
    response.await().asSubscription(ownerId, token)
    }
    }
    class top
    class bottom
    

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69. interface Database {
    suspend fun subscription(subscriptionId: String): Subscription?
    suspend fun subscriptionByToken(token: String): Subscription?
    suspend fun subscriptionByUserId(userId: String): Subscription?
    suspend fun createSubscription(subscription: Subscription): Subscription
    }
    

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70. // Return subscription or 404
    @JsonClass(generateAdapter = true)
    data class Request(
    val userId: String,
    val packageName: String,
    val productId: String,
    val token: String
    )b
    post("/verify") {
    routing {
    fun Application.verify() {
    }
    }
    }
    install(ContentNegotiation)
    install(StatusPages) { }1
    ...
    { }2
    ...
    val request = call.receive()
    // Find valid subscription in db or remotely
    // Save to database
    

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71. // Return subscription or 404
    @JsonClass(generateAdapter = true)
    data class Request(
    val userId: String,
    val packageName: String,
    post("/verify") {
    routing {
    fun Application.verify() {
    }
    }
    }
    install(ContentNegotiation)
    install(StatusPages) { }1
    ...
    { }2
    ...
    val request = call.receive()
    // Find valid subscription in db or remotely
    // Save to database
    ≈
    ≈
    ≈
    val api = TotallyRealApi()
    ≈
    ≈
    ≈
    

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72. // Return subscription or 404
    @JsonClass(generateAdapter = true)
    data class Request(
    val userId: String,
    post("/verify") {
    routing {
    fun Application.verify() {
    }
    }
    }
    install(ContentNegotiation)
    install(StatusPages) { }1
    ...
    { }2
    ...
    val request = call.receive()
    // Find valid subscription in db or remotely
    // Save to database
    ≈
    ≈
    ≈
    val db = InMemoryDatabase()
    val api = TotallyRealApi()
    ≈
    ≈
    ≈
    

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73. // Return subscription or 404
    @JsonClass(generateAdapter = true)
    data class Request(
    val userId: String,
    post("/verify") {
    routing {
    fun Application.verify() {
    }
    }
    }
    install(ContentNegotiation)
    install(StatusPages) { }1
    ...
    { }2
    ...
    val request = call.receive()
    // Save to database
    ≈
    ≈
    ≈
    val db = InMemoryDatabase()
    val api = TotallyRealApi()
    ≈
    ≈
    val subscription = db.subscriptionByUserId(request.userId)
    

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74. // Return subscription or 404
    @JsonClass(generateAdapter = true)
    data class Request(
    post("/verify") {
    routing {
    fun Application.verify() {
    }
    }
    }
    install(ContentNegotiation)
    install(StatusPages) { }1
    ...
    { }2
    ...
    val request = call.receive()
    ≈
    ≈
    val db = InMemoryDatabase()
    val api = TotallyRealApi()
    ≈
    ?: api.findSubscription(request.userId, request.packageName
    request.productId, request.token)
    val subscription = db.subscriptionByUserId(request.userId)
    

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75. ?: api.findSubscription(request.userId, request.packageName
    request.productId, request.token)
    // Return subscription or 404
    @JsonClass(generateAdapter = true)
    data class Request(
    post("/verify") {
    routing {
    fun Application.verify() {
    }
    }
    }
    install(ContentNegotiation)
    install(StatusPages) { }1
    ...
    { }2
    ...
    val request = call.receive()
    ≈
    ≈
    val db = InMemoryDatabase()
    val api = TotallyRealApi()
    ≈
    ?.also { db.createSubscription(it) }
    val subscription = db.subscriptionByUserId(request.userId)
    

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76. post("/verify") {
    routing {
    fun Application.verify() {
    }
    }
    install(ContentNegotiation)
    install(StatusPages) { }1
    ...
    { }2
    ...
    val request = call.receive()
    ≈
    ≈
    val db = InMemoryDatabase()
    val api = TotallyRealApi()
    val subscription = db.subscriptionByUserId(request.userId)
    if (subscription == null) {
    call.respond(HttpStatusCode.NotFound, "Subscription invalid.")
    } else {
    call.respond(subscription)
    }
    ?: api.findSubscription(request.userId, request.packageName
    request.productId, request.token)
    ?.also { db.createSubscription(it) }
    

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77. → curl -X POST -H "Content-Type: application/json" -d @valid.json http://localhost:8080/verify
    

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78. → curl -X POST -H "Content-Type: application/json" -d @valid.json http://localhost:8080/verify
    {“canceled":false,"expiryDate":"2018-10-12T04:35:21.000Z","id":"668245e4-b673-4258-
    ba7c-4b0367833e61","ownerId":"rharter","startDate":"2018-09-12T04:35:21.000Z","token":"token3"}
    

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79. → curl -X POST -H "Content-Type: application/json" -d @valid.json http://localhost:8080/verify
    {“canceled":false,"expiryDate":"2018-10-12T04:35:21.000Z","id":"668245e4-b673-4258-
    ba7c-4b0367833e61","ownerId":"rharter","startDate":"2018-09-12T04:35:21.000Z","token":"token3"}
    →
    → curl -X POST -H "Content-Type: application/json" -d @invalid.json http://localhost:8080/verify
    

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80. → curl -X POST -H "Content-Type: application/json" -d @valid.json http://localhost:8080/verify
    {“canceled":false,"expiryDate":"2018-10-12T04:35:21.000Z","id":"668245e4-b673-4258-
    ba7c-4b0367833e61","ownerId":"rharter","startDate":"2018-09-12T04:35:21.000Z","token":"token3"}
    →
    → curl -X POST -H "Content-Type: application/json" -d @invalid.json http://localhost:8080/verify
    Subscription invalid.
    →
    

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81. Templates
    

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82. post("/verify") {
    routing {
    fun Application.verify() {
    }
    }
    install(ContentNegotiation)
    install(StatusPages) { }1
    ...
    { }2
    ...
    val request = call.receive()
    val db = InMemoryDatabase()
    val api = TotallyRealApi()
    val subscription = db.subscriptionByUserId(request.userId)
    if (subscription == null) {
    call.respond(HttpStatusCode.NotFound, "Subscription invalid.")
    } else {
    call.respond(subscription)
    }
    ?: api.findSubscription(request.userId, request.packageName
    request.productId, request.token)
    ?.also { db.createSubscription(it) }
    

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83. post("/verify") {
    routing {
    fun Application.verify() {
    }
    }
    install(ContentNegotiation)
    install(StatusPages) { }1
    ...
    { }2
    ...
    ... }3
    ...
    

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84. get(“/subscriptions") {
    routing {
    fun Application.verify() {
    }
    }
    install(ContentNegotiation)
    install(StatusPages) { }1
    ...
    { }2
    ...
    }4
    ...
    post("/verify") {... }3
    

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85. get(“/subscriptions") {
    routing {
    fun Application.verify() {
    }
    }
    install(ContentNegotiation)
    install(StatusPages) { }1
    ...
    { }2
    ...
    }4
    ...
    post("/verify") {... }3
    val subscriptions = db.subscriptions()
    call.respond(subscriptions)
    

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86. http://localhost:8080/subscriptions
    [
    {
    "id": "sub-1",
    "ownerId": "Bandalls",
    "token": "asdf98hn",
    "startDate": "Sep 11, 2018 11:35:21 PM",
    "expiryDate": "Oct 11, 2018 11:35:21 PM",
    "canceled": true
    },
    {
    "id": "sub-2",
    "ownerId": "Editussion",
    "token": "asdf092s",
    "startDate": "Sep 11, 2018 11:35:21 PM",
    "expiryDate": "Oct 11, 2018 11:35:21 PM",
    "canceled": false
    },
    {
    "id": "sub-3",
    "ownerId": "Liveltekah",
    "token": "gju0u0fe",
    "startDate": "Sep 11, 2018 11:35:21 PM",
    "expiryDate": "Oct 11, 2018 11:35:21 PM",
    "canceled": false
    },
    {
    "id": "sub-4",
    "ownerId": "Ortspoon",
    "token": "diiefh48",
    "startDate": "Sep 11, 2018 11:35:21 PM",
    "expiryDate": "Oct 11, 2018 11:35:21 PM",
    "canceled": true
    },
    {
    "id": "sub-5",
    "ownerId": "Reakefit",
    "token": "dg09uui2",
    http://localhost:8080/subs…
    

    View Slide

87. get(“/subscriptions") {
    routing {
    fun Application.verify() {
    }
    }
    install(ContentNegotiation)
    install(StatusPages) { }1
    ...
    { }2
    ...
    }4
    ...
    post("/verify") {... }3
    val subscriptions = db.subscriptions()
    call.respond(subscriptions)
    

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88. install(FreeMarker) {
    get(“/subscriptions") {
    routing {
    fun Application.verify() {
    }
    }
    install(ContentNegotiation)
    install(StatusPages) { }1
    ...
    { }2
    ...
    }4
    ...
    post("/verify") {... }3
    val subscriptions = db.subscriptions()
    call.respond(subscriptions)
    }freemarker
    

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89. install(FreeMarker) {
    get(“/subscriptions") {
    routing {
    fun Application.verify() {
    }
    }
    install(ContentNegotiation)
    install(StatusPages) { }1
    ...
    { }2
    ...
    }4
    ...
    post("/verify") {... }3
    val subscriptions = db.subscriptions()
    call.respond(subscriptions)
    }freemarker
    templateLoader = ClassTemplateLoader(
    this@module.javaClass.classLoader,
    "templates"
    )
    

    View Slide

90. install(FreeMarker) {
    get(“/subscriptions") {
    routing {
    fun Application.verify() {
    }
    }
    install(ContentNegotiation)
    install(StatusPages) { }1
    ...
    { }2
    ...
    }4
    ...
    post("/verify") {... }3
    val subscriptions = db.subscriptions()
    call.respond(subscriptions)
    }freemarker
    ...
    

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91. install(FreeMarker) {
    get(“/subscriptions") {
    routing {
    fun Application.verify() {
    }
    }
    install(ContentNegotiation)
    install(StatusPages) { }1
    ...
    { }2
    ...
    }4
    ...
    post("/verify") {... }3
    val subscriptions = db.subscriptions()
    call.respond(
    }freemarker
    ...
    subscriptions)respond
    

    View Slide

92. install(FreeMarker) {
    get(“/subscriptions") {
    routing {
    fun Application.verify() {
    }
    }
    install(ContentNegotiation)
    install(StatusPages) { }1
    ...
    { }2
    ...
    }4
    ...
    post("/verify") {... }3
    val subscriptions = db.subscriptions()
    call.respond(
    }freemarker
    ...
    )respond
    FreeMarkerContent("subscriptions.ftl",
    mapOf("subscriptions" to ))
    subscriptions
    

    View Slide

93. install(FreeMarker) {
    get(“/subscriptions") {
    routing {
    fun Application.verify() {
    install(ContentNegotiation)
    install(StatusPages) { }1
    ...
    { }2
    ...
    ...
    val subscriptions = db.subscriptions()
    call.respond(
    }freemarker
    ...
    FreeMarkerContent("subscriptions.ftl",
    mapOf("subscriptions" to ))
    subscriptions
    }
    }
    }4
    post("/verify") {... }3
    )respond
    

    View Slide

94. install(FreeMarker) {
    get(“/subscriptions") {
    routing {
    fun Application.verify() {
    install(ContentNegotiation)
    install(StatusPages) { }1
    ...
    { }2
    ...
    ...
    val subscriptions = db.subscriptions()
    call.respond(
    }freemarker
    ...
    FreeMarkerContent("subscriptions.ftl",
    mapOf("subscriptions" to ))
    subscriptions
    }
    }
    }4
    post("/verify") {... }3
    )respond
    

    View Slide

95. 
    
    
    
    
    
    
    
    
    Home
    
    
    
    search
    
    
    
    Enter your query...
    
    
    
    more_vert
    
    
    About
    Contact
    Legal information
    
    
    
    
    
    
    
    
    Owner ID
    Start Date
    Expiry Date
    Cancelled
    
    
    
    <#list subscriptions as subscription>
    
    ${subscription.ownerId}
    ${subscription.startDate?date}
    ${subscription.expiryDate?date}
    
    ${subscription.canceled?string('yes', 'no')}
    
    
    #list>
    
    
    
    
    
    

    View Slide

96. Start Date
    Expiry Date
    Cancelled
    
    
    
    <#list subscriptions as subscription>
    
    ${subscription.ownerId}
    ${subscription.startDate?date}
    ${subscription.expiryDate?date}
    
    ${subscription.canceled?string('yes', 'no')}
    
    
    #list>
    
    /table>
    >
    

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97. [
    {
    "id": "sub-1",
    "ownerId": "Bandalls",
    "token": "asdf98hn",
    "startDate": "Sep 11, 2018 11:35:21 PM",
    "expiryDate": "Oct 11, 2018 11:35:21 PM",
    "canceled": true
    },
    {
    "id": "sub-2",
    "ownerId": "Editussion",
    "token": "asdf092s",
    "startDate": "Sep 11, 2018 11:35:21 PM",
    "expiryDate": "Oct 11, 2018 11:35:21 PM",
    "canceled": false
    },
    {
    "id": "sub-3",
    "ownerId": "Liveltekah",
    "token": "gju0u0fe",
    "startDate": "Sep 11, 2018 11:35:21 PM",
    "expiryDate": "Oct 11, 2018 11:35:21 PM",
    "canceled": false
    },
    {
    "id": "sub-4",
    "ownerId": "Ortspoon",
    "token": "diiefh48",
    "startDate": "Sep 11, 2018 11:35:21 PM",
    "expiryDate": "Oct 11, 2018 11:35:21 PM",
    "canceled": true
    },
    {
    "id": "sub-5",
    "ownerId": "Reakefit",
    "token": "dg09uui2",
    http://localhost:8080/subscriptions
    http://localhost:8080/subs…
    

    View Slide

98. [
    {
    "id": "sub-1",
    "ownerId": "Bandalls",
    "token": "asdf98hn",
    "startDate": "Sep 11, 2018 11:35:21 PM",
    "expiryDate": "Oct 11, 2018 11:35:21 PM",
    "canceled": true
    },
    {
    "id": "sub-2",
    "ownerId": "Editussion",
    "token": "asdf092s",
    "startDate": "Sep 11, 2018 11:35:21 PM",
    "expiryDate": "Oct 11, 2018 11:35:21 PM",
    "canceled": false
    },
    {
    "id": "sub-3",
    "ownerId": "Liveltekah",
    "token": "gju0u0fe",
    "startDate": "Sep 11, 2018 11:35:21 PM",
    "expiryDate": "Oct 11, 2018 11:35:21 PM",
    "canceled": false
    },
    {
    "id": "sub-4",
    "ownerId": "Ortspoon",
    "token": "diiefh48",
    "startDate": "Sep 11, 2018 11:35:21 PM",
    "expiryDate": "Oct 11, 2018 11:35:21 PM",
    "canceled": true
    },
    {
    "id": "sub-5",
    "ownerId": "Reakefit",
    "token": "dg09uui2",
    http://localhost:8080/subscriptions
    http://localhost:8080/subs…
    

    View Slide

99. http://localhost:8080/subscriptions
    http://localhost:8080/subs…
    

    View Slide

100. Authentication
     

     View Slide

101. }routing
     install(FreeMarker) {
     get("/subscriptions") {
     routing {
     fun Application.verify() {
     install(ContentNegotiation)
     install(StatusPages) { }1
     ...
     { }2
     ...
     ...
     val subscriptions = db.subscriptions()
     call.respond(
     }freemarker
     ...
     FreeMarkerContent("subscriptions.ftl",
     mapOf("subscriptions" to ))
     subscriptions
     }
     }4
     post("/verify") {... }3
     )respond
     

     View Slide

102. }routing
     install(FreeMarker) {
     get("/subscriptions") {
     routing {
     fun Application.verify() {
     install(ContentNegotiation)
     install(StatusPages) { }1
     ...
     { }2
     ...
     }freemarker
     ...
     }
     }4
     post("/verify") {... }3
     ...
     

     View Slide

103. }routing
     install(FreeMarker) {
     get("/subscriptions") {
     routing {
     fun Application.verify() {
     install(ContentNegotiation)
     install(StatusPages) { }1
     ...
     { }2
     ...
     }freemarker
     ...
     }
     }4
     post("/verify") {... }3
     ...
     install(Authentication)
     s
     

     View Slide

104. install(FreeMarker) {
     get("/subscriptions") {
     routing {
     fun Application.verify() {
     install(ContentNegotiation)
     install(StatusPages) { }1
     ...
     { }2
     ...
     }freemarker
     ...
     }
     }4
     post("/verify") {... }3
     ...
     install(Authentication) {auth
     }auth
     }basic
     basic(name = "userAuth") {basic
     }routing
     s
     

     View Slide

105. install(FreeMarker) {
     get("/subscriptions") {
     routing {
     fun Application.verify() {
     install(ContentNegotiation)
     install(StatusPages) { }1
     ...
     { }2
     ...
     }freemarker
     ...
     }
     }4
     post("/verify") {... }3
     ...
     install(Authentication) {auth
     }auth
     }basic
     realm = "Verifier"
     basic(name = "userAuth") {basic
     }routing
     s
     

     View Slide

106. }routing
     install(FreeMarker) {
     get("/subscriptions") {
     routing {
     fun Application.verify() {
     install(ContentNegotiation)
     install(StatusPages) { }1
     ...
     { }2
     ...
     }freemarker
     ...
     }
     }4
     post("/verify") {... }3
     ...
     install(Authentication)
     s
     {auth
     }auth
     }validate
     }basic
     validate { credentials ->
     realm = "Verifier"
     basic(name = "userAuth") {basic
     

     View Slide

107. }routing
     install(FreeMarker) {
     get("/subscriptions") {
     routing {
     fun Application.verify() {
     install(ContentNegotiation)
     install(StatusPages) { }1
     ...
     { }2
     ...
     }freemarker
     ...
     }
     }4
     post("/verify") {... }3
     ...
     install(Authentication)
     s
     {auth
     }auth
     authService.authenticate(credentials.name, credentials.password)
     }validate
     }basic
     validate { credentials ->
     realm = "Verifier"
     basic(name = "userAuth") {basic
     

     View Slide

108. }routing
     install(FreeMarker) {
     get("/subscriptions") {
     routing {
     fun Application.verify() {
     install(ContentNegotiation)
     install(StatusPages) { }1
     ...
     { }2
     ...
     }freemarker
     ...
     }
     }4
     post("/verify") {... }3
     ...
     install(Authentication)
     s
     {auth
     }auth
     ...
     

     View Slide

109. }routing
     install(FreeMarker) {
     get("/subscriptions") {
     routing {
     fun Application.verify() {
     install(ContentNegotiation)
     install(StatusPages) { }1
     ...
     { }2
     ...
     }freemarker
     ...
     }
     }4
     post("/verify") {... }3
     ...
     install(Authentication) {auth
     }auth
     ...
     

     View Slide

110. get("/subscriptions") {
     fun Application.verify() {
     }
     }
     }4
     post("/verify") {... }3
     ...
     authenticate("userAuth") {
     }
     install(FreeMarker) {
     routing {
     install(ContentNegotiation)
     install(StatusPages) { }1
     ...
     { }2
     ...
     }freemarker
     ...
     install(Authentication) {auth
     }auth
     ...
     

     View Slide

111. fun Application.verify() {
     get("/subscriptions") {
     }
     }
     }4
     post("/verify") {... }3
     ...
     authenticate("userAuth") {
     }
     install(FreeMarker) {
     routing {
     install(ContentNegotiation)
     install(StatusPages) { }1
     ...
     { }2
     ...
     }freemarker
     ...
     install(Authentication) {auth
     }auth
     ...
     

     View Slide

112. fun Application.verify() {
     }
     }
     post("/verify") {... }3
     authenticate("userAuth") {
     }
     get("/subscriptions") {
     val subscriptions = db.subscriptions()
     call.respond(
     FreeMarkerContent("subscriptions.ftl",
     mapOf("subscriptions" to subscriptions
     }4
     )respond
     ))
     install(FreeMarker) {
     routing {
     install(ContentNegotiation)
     install(StatusPages) { }1
     ...
     { }2
     ...
     }freemarker
     ...
     install(Authentication) {auth
     }auth
     ...
     

     View Slide

113. fun Application.verify() {
     }
     }
     post("/verify") {... }3
     authenticate("userAuth") {
     }
     get("/subscriptions") {
     val subscriptions = db.subscriptions()
     call.respond(
     FreeMarkerContent("subscriptions.ftl",
     mapOf( subscriptions
     }4
     )respond
     val user = call.authentication.principal
     d
     "subscriptions" to ))
     install(FreeMarker) {
     routing {
     install(ContentNegotiation)
     install(StatusPages) { }1
     ...
     { }2
     ...
     }freemarker
     ...
     install(Authentication) {auth
     }auth
     ...
     

     View Slide

114. }
     val subscriptions = db.subscriptions()
     call.respond(
     FreeMarkerContent("subscriptions.ftl",
     mapOf(
     subscriptions
     }4
     )respond
     val user = call.authentication.principal
     d
     )
     "subscriptions" to
     )
     ,
     "user" to user
     fun Application.verify() {
     authenticate("userAuth") {
     get("/subscriptions") {
     install(FreeMarker) {
     routing {
     install(ContentNegotiation)
     install(StatusPages) { }1
     ...
     { }2
     ...
     }freemarker
     ...
     install(Authentication) {auth
     }auth
     ...
     

     View Slide

115. [
     {
     "id": "sub-1",
     "ownerId": "Bandalls",
     "token": "asdf98hn",
     "startDate": "Sep 11, 2018 11:35:21 PM",
     "expiryDate": "Oct 11, 2018 11:35:21 PM",
     "canceled": true
     },
     {
     "id": "sub-2",
     "ownerId": "Editussion",
     "token": "asdf092s",
     "startDate": "Sep 11, 2018 11:35:21 PM",
     "expiryDate": "Oct 11, 2018 11:35:21 PM",
     "canceled": false
     },
     {
     "id": "sub-3",
     "ownerId": "Liveltekah",
     "token": "gju0u0fe",
     "startDate": "Sep 11, 2018 11:35:21 PM",
     "expiryDate": "Oct 11, 2018 11:35:21 PM",
     "canceled": false
     },
     {
     "id": "sub-4",
     "ownerId": "Ortspoon",
     "token": "diiefh48",
     "startDate": "Sep 11, 2018 11:35:21 PM",
     "expiryDate": "Oct 11, 2018 11:35:21 PM",
     "canceled": true
     },
     {
     "id": "sub-5",
     "ownerId": "Reakefit",
     "token": "dg09uui2",
     http://localhost:8080/subscriptions
     http://localhost:8080/subs…
     

     View Slide

116. http://localhost:8080/subscriptions
     http://localhost:8080/subs…
     Sign in
     http://localhost:8080
     Username
     Password
     Sign in
     Cancel
     

     View Slide

117. http://localhost:8080/subscriptions
     http://localhost:8080/subs…
     Sign in
     http://localhost:8080
     Username
     Password
     Sign in
     Cancel
     admin
     •••••••••••
     

     View Slide

118. http://localhost:8080/subscriptions
     http://localhost:8080/subs…
     Ryan
     

     View Slide

119. Forms
     

     View Slide

120. http://localhost:8080/subscriptions
     http://localhost:8080/subs…
     Ryan
     

     View Slide

121. http://localhost:8080/subscriptions
     http://localhost:8080/subs…
     Ryan
     

     View Slide

122. Ryan
     

     View Slide

123. }
     }
     post("/verify") {... }3
     }
     }4
     d
     fun Application.verify() {
     authenticate("userAuth") {
     get("/subscriptions") {
     install(FreeMarker) {
     routing {
     install(ContentNegotiation)
     install(StatusPages) { }1
     ...
     { }2
     ...
     }freemarker
     ...
     install(Authentication) {auth
     }auth
     ...
     ...
     

     View Slide

124. post("/verify") {... }3
     }
     }4
     authenticate("userAuth") {
     get("/subscriptions") {
     install(FreeMarker) {
     routing {
     }freemarker
     ...
     install(Authentication) {auth
     }auth
     ...
     ...
     post("/subscriptions") {
     }post
     get("/subscriptions") {
     

     View Slide

125. post("/verify") {... }3
     }
     }4
     authenticate("userAuth") {
     get("/subscriptions") {
     install(FreeMarker) {
     routing {
     }freemarker
     ...
     install(Authentication) {auth
     }auth
     ...
     ...
     post("/subscriptions") {
     }post
     get("/subscriptions") {
     val parameters = call.receiveParameters()
     

     View Slide

126. post("/verify") {... }3
     }
     }4
     authenticate("userAuth") {
     get("/subscriptions") {
     install(FreeMarker) {
     routing {
     }freemarker
     ...
     install(Authentication) {auth
     }auth
     ...
     ...
     post("/subscriptions") {
     }post
     get("/subscriptions") {
     val parameters = call.receiveParameters()
     val id = parameters[“id"]
     post("/subscriptions") {
     end post
     

     View Slide

127. post("/verify") {... }3
     }
     }4
     authenticate("userAuth") {
     get("/subscriptions") {
     install(FreeMarker) {
     routing {
     }freemarker
     ...
     install(Authentication) {auth
     }auth
     ...
     ...
     post("/subscriptions") {
     }post
     get("/subscriptions") {
     val parameters = call.receiveParameters()
     val id = parameters[“id"]
     ?: throw IllegalArgumentException("Missing parameter: id")
     post("/subscriptions") {
     end post
     

     View Slide

128. post("/verify") {... }3
     }
     }4
     authenticate("userAuth") {
     get("/subscriptions") {
     install(FreeMarker) {
     routing {
     }freemarker
     ...
     install(Authentication) {auth
     }auth
     ...
     ...
     post("/subscriptions") {
     }post
     get("/subscriptions") {
     val parameters = call.receiveParameters()
     val id = parameters[“id"]
     ?: throw IllegalArgumentException("Missing parameter: id")
     val action = parameters[“action"]
     ?: throw IllegalArgumentException("Missing parameter: action")
     post("/subscriptions") {
     end post
     

     View Slide

129. post("/verify") {... }3
     }
     }4
     authenticate("userAuth") {
     get("/subscriptions") {
     install(FreeMarker) {
     routing {
     }freemarker
     ...
     install(Authentication) {auth
     }auth
     ...
     ...
     post("/subscriptions") {
     }post
     get("/subscriptions") {
     val parameters = call.receiveParameters()
     val id = parameters[“id"]
     ?: throw IllegalArgumentException("Missing parameter: id")
     val action = parameters[“action"]
     ?: throw IllegalArgumentException("Missing parameter: action")
     when (action) {
     }when
     post("/subscriptions") {
     val parameters = call.receiveParameters()
     ids and such
     end post
     

     View Slide

130. post("/verify") {... }3
     }
     }4
     authenticate("userAuth") {
     get("/subscriptions") {
     install(FreeMarker) {
     routing {
     }freemarker
     ...
     install(Authentication) {auth
     }auth
     ...
     ...
     post("/subscriptions") {
     }post
     get("/subscriptions") {
     val parameters = call.receiveParameters()
     val id = parameters[“id"]
     ?: throw IllegalArgumentException("Missing parameter: id")
     val action = parameters[“action"]
     ?: throw IllegalArgumentException("Missing parameter: action")
     when (action) {
     }when
     "delete" -> db.deleteSubscription(id)
     post("/subscriptions") {
     val parameters = call.receiveParameters()
     ids and such
     end post
     when (action) {
     end when
     

     View Slide

131. post("/verify") {... }3
     }
     }4
     authenticate("userAuth") {
     get("/subscriptions") {
     install(FreeMarker) {
     routing {
     }freemarker
     ...
     install(Authentication) {auth
     }auth
     ...
     ...
     post("/subscriptions") {
     }post
     get("/subscriptions") {
     val parameters = call.receiveParameters()
     val id = parameters[“id"]
     ?: throw IllegalArgumentException("Missing parameter: id")
     val action = parameters[“action"]
     ?: throw IllegalArgumentException("Missing parameter: action")
     when (action) {
     }when
     "delete" -> db.deleteSubscription(id)
     "cancel" -> {
     } -> cancel
     post("/subscriptions") {
     val parameters = call.receiveParameters()
     ids and such
     end post
     when (action) {
     “delete” -> db.deleteSubscription(id)
     end when
     

     View Slide

132. post("/verify") {... }3
     }
     }4
     authenticate("userAuth") {
     get("/subscriptions") {
     install(FreeMarker) {
     routing {
     }freemarker
     ...
     install(Authentication) {auth
     }auth
     ...
     ...
     post("/subscriptions") {
     }post
     get("/subscriptions") {
     val parameters = call.receiveParameters()
     val id = parameters[“id"]
     ?: throw IllegalArgumentException("Missing parameter: id")
     val action = parameters[“action"]
     ?: throw IllegalArgumentException("Missing parameter: action")
     when (action) {
     }when
     "delete" -> db.deleteSubscription(id)
     "cancel" -> {
     db.subscription(id)
     } -> cancel
     post("/subscriptions") {
     val parameters = call.receiveParameters()
     ids and such
     end post
     when (action) {
     “delete” -> db.deleteSubscription(id)
     end when
     

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133. post("/verify") {... }3
     }
     }4
     authenticate("userAuth") {
     get("/subscriptions") {
     install(FreeMarker) {
     routing {
     }freemarker
     ...
     install(Authentication) {auth
     }auth
     ...
     ...
     post("/subscriptions") {
     }post
     get("/subscriptions") {
     val parameters = call.receiveParameters()
     val id = parameters[“id"]
     ?: throw IllegalArgumentException("Missing parameter: id")
     val action = parameters[“action"]
     ?: throw IllegalArgumentException("Missing parameter: action")
     when (action) {
     }when
     "delete" -> db.deleteSubscription(id)
     "cancel" -> {
     db.subscription(id)
     db.putSubscription(it.copy(canceled = true))
     }db.subscription(id)?.also
     } -> cancel
     ?.also {
     post("/subscriptions") {
     val parameters = call.receiveParameters()
     ids and such
     end post
     when (action) {
     “delete” -> db.deleteSubscription(id)
     end when
     

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134. post("/verify") {... }3
     }
     }4
     authenticate("userAuth") {
     get("/subscriptions") {
     install(FreeMarker) {
     routing {
     }freemarker
     ...
     install(Authentication) {auth
     }auth
     ...
     ...
     post("/subscriptions") {
     val parameters = call.receiveParameters()
     val id = parameters[“id"]
     ?: throw IllegalArgumentException("Missing parameter: id")
     val action = parameters[“action"]
     ?: throw IllegalArgumentException("Missing parameter: action")
     when (action) {
     "delete" -> db.deleteSubscription(id)
     "cancel" -> {
     db.subscription(id)?.also {
     db.putSubscription(it.copy(canceled = true))
     }db.subscription(id)?.also
     } -> cancel
     }when
     }post
     call.respondRedirect("/subscriptions")
     get("/subscriptions") {
     post("/subscriptions") {
     val parameters = call.receiveParameters()
     ids and such
     end post
     when (action) {
     “delete” -> db.deleteSubscription(id)
     end when
     cancel stuff
     

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135. Expiry Date
     Cancelled
     
     
     
     <#list subscriptions as subscription>
     
     ${subscription.ownerId}
     ${subscription.startDate?date}
     ${subscription.expiryDate?date}
     
     ${subscription.canceled?string('yes', 'no')}
     
     
     #list>
     
     /table>
     >
     

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136. 
     ${subscription.canceled?string('yes', 'no')}
     
     
     #list>
     
     
     
     
     
     <#if subscription.canceled>disabled#if>>
     block
     
     
     
     
     
     
     delete
     
     
     
     td
     /td
     

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137. 
     ${subscription.canceled?string('yes', 'no')}
     
     
     #list>
     
     
     
     
     
     <#if subscription.canceled>disabled#if>>
     block
     
     
     
     
     
     
     delete
     
     
     
     td
     /td
     start td
     End td
     

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138. 
     ${subscription.canceled?string('yes', 'no')}
     
     
     #list>
     
     
     
     
     
     <#if subscription.canceled>disabled#if>>
     block
     
     
     
     
     
     
     delete
     
     
     
     td
     /td
     start td
     End td
     form content
     

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139. 
     ${subscription.canceled?string('yes', 'no')}
     
     
     #list>
     
     
     
     
     
     <#if subscription.canceled>disabled#if>>
     block
     
     
     
     
     
     
     delete
     
     
     
     td
     /td
     start td
     End td
     formstart td
     /form td
     button
     

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140. 
     ${subscription.canceled?string('yes', 'no')}
     
     
     #list>
     
     
     
     
     
     <#if subscription.canceled>disabled#if>>
     block
     
     
     
     
     
     
     delete
     
     
     
     td
     /td
     start td
     End td
     formstart td
     /form td
     inputs
     

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141. http://localhost:8080/subscriptions
     http://localhost:8080/subs…
     Ryan
     

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142. http://localhost:8080/subscriptions
     http://localhost:8080/subs…
     Ryan
     Cancel
     

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143. http://localhost:8080/subscriptions
     http://localhost:8080/subs…
     Ryan
     

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144. Ryan
     

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145. Ryan
     

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146. Ktor
     • Web
     
     • Github
     
     • Slack
     
     http://ktor.io
     
     ktorio / ktor
     
     kotlinlang #ktor
     
     

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147. Ktor
     • Web
     
     • Github
     
     • Slack
     
     • Me
     http://ktor.io
     
     ktorio / ktor
     
     kotlinlang #ktor
     
     @rharter
     

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148. Servers ❤ Kotlin
     Ryan Harter
     @rharter
     

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