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Scaling Dagger
DI in a modular world
Droidcon Madrid 2019
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@CesarDielo
César
Puerta
Technical Lead
Twitter for Android
@mrmans0n
Nacho
López
Software Engineer
Android Foundation Architecture
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Author: Ben Sandofsky
Date: Mon Jun 21 23:24:55 2010 -0700
Initial import.
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Author: Ben Sandofsky
Date: Mon Jun 21 23:24:55 2010 -0700
Initial import.
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Periscope
@PeriscopeCo
You might have heard some
news: It involves a blue bird.
#YouCanGuessTheRest
#WeJoinedTheFlockInJanuary
13 Mar 2015
629 761
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+
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D
D
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DI is important
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DI is important
Reusability
for…
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DI is important
Testability
for…
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DI is important
Correctness
for…
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DI is important
Refactoring
for…
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regardless of app size
DI is important
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Static checks
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Static checks
Errors at compile time > Runtime errors
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Description: [Dagger/MissingBinding]
com.twitter.ui.util.UiArchLayoutContentViewProvider cannot be provided
without an @Inject constructor or an @Provides-annotated method.
Description: [Dagger/DuplicateBindings]
com.twitter.ui.util.UiArchLayoutContentViewProvider is bound multiple
times.
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Code generation
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Code generation
Automating the creation of glue code
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val inflater = LayoutInflater.from(context)
val renderer = Renderer(inflater)
val database = Database()
val timeline = Timeline(database, renderer)
class Renderer
(database: Database, renderer: Renderer)
class Timeline
class Database()
(inflater: LayoutInflater)
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class Renderer
(database: Database, renderer: Renderer)
class Timeline
class Database ()
(inflater: LayoutInflater)
@Inject constructor
@Inject constructor
@Inject constructor
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Graph Architecture
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Graph Architecture
Scoped object graphs mapping to the app lifecycle
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Graph Architecture
Scoped object graphs mapping to the app lifecycle
@Component
@Subcomponent
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@ApplicationScope
@UserScope
@RetainedScope
@ViewScope
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@Component(modules = [ApplicationModule::class])
@ApplicationScope
interface ApplicationObjectGraph
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@Component(modules = [ApplicationModule::class])
@ApplicationScope
interface ApplicationObjectGraph {
fun userObjectGraphBuilder(): UserObjectGraph.Builder
}
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@Subcomponent(modules = [UserModule::class])
@UserScope
interface UserObjectGraph
@Component(modules = [ApplicationModule::class])
@ApplicationScope
interface ApplicationObjectGraph {
fun userObjectGraphBuilder(): UserObjectGraph.Builder
}
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{
fun featureRetainedBuilder(): FeatureRetainedObjectGraph.Builder
}
@Subcomponent(modules = [UserModule::class])
@UserScope
interface UserObjectGraph
@Component(modules = [ApplicationModule::class])
@ApplicationScope
interface ApplicationObjectGraph {
fun userObjectGraphBuilder(): UserObjectGraph.Builder
}
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{
fun featureRetainedBuilder(): FeatureRetainedObjectGraph.Builder
}
@Subcomponent(modules = [UserModule::class])
@UserScope
interface UserObjectGraph
@ApplicationScope
interface ApplicationObjectGraph {
fun userObjectGraphBuilder(): UserObjectGraph.Builder
}
@Subcomponent(modules = [FeatureRetainedModule::class])
@RetainedScope
interface FeatureRetainedObjectGraph
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{
fun featureRetainedBuilder(): FeatureRetainedObjectGraph.Builder
}
@Subcomponent(modules = [UserModule::class])
@UserScope
interface UserObjectGraph
@ApplicationScope
interface ApplicationObjectGraph {
fun userObjectGraphBuilder(): UserObjectGraph.Builder
}
@Subcomponent(modules = [FeatureRetainedModule::class])
@RetainedScope
interface FeatureRetainedObjectGraph {
fun featureViewGraphBuilder(): FeatureViewObjectGraph.Builder
}
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{
fun featureRetainedBuilder(): FeatureRetainedObjectGraph.Builder
}
@UserScope
interface UserObjectGraph
@Subcomponent(modules = [FeatureRetainedModule::class])
@RetainedScope
interface FeatureRetainedObjectGraph {
fun featureViewGraphBuilder(): FeatureViewObjectGraph.Builder
}
@Subcomponent(modules = [FeatureViewModule::class])
@ViewScope
interface FeatureViewObjectGraph
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{
fun featureRetainedBuilder(): FeatureRetainedObjectGraph.Builder
}
@UserScope
interface UserObjectGraph
Components or ?
Subcomponents
@ApplicationScope
@UserScope
@RetainedScope
@ViewScope
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Components for the root graph
for the nested graphs
Subcomponents
@ApplicationScope
@UserScope
@RetainedScope
@ViewScope
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Where do we place our graphs?
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No content
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@ApplicationScope
@UserScope
@RetainedScope
@ViewScope
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Let’s compose a
Tweet
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:features:composer
@RetainedScope
@ViewScope
@ApplicationScope
@UserScope
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:features:composer
ComposerActivity
ComposerViewModel
ComposerViewDelegate
@RetainedScope
@ViewScope
@ApplicationScope
@UserScope
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:features:composer
ComposerActivity
ComposerViewModel
ComposerViewDelegate
@RetainedScope
@ViewScope
@ApplicationScope
@UserScope
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:subsystems:tweets
TweetRepository
:features:composer
@RetainedScope
@ViewScope
@ApplicationScope
@UserScope
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:subsystems:tweets
TweetRepository
:features:composer
@RetainedScope
@ViewScope
@ApplicationScope
@UserScope
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:subsystems:tweets
TweetRepository
:features:composer
@RetainedScope
@ViewScope
@ApplicationScope
@UserScope
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:subsystems:tweets
TweetRepository
:features:composer
@RetainedScope
@ViewScope
@ApplicationScope
@UserScope
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:twitter:media
ImageUploader
:features:composer
:subsystems:tweets
@RetainedScope
@ViewScope
@UserScope
@ApplicationScope
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:twitter:media
ImageUploader
:features:composer
:subsystems:tweets
@RetainedScope
@ViewScope
@ApplicationScope
@UserScope
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:twitter:media
ImageUploader
:features:composer
:subsystems:tweets
@RetainedScope
@ViewScope
@ApplicationScope
@UserScope
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:twitter:media
ImageUploader
:features:composer
:subsystems:tweets
@RetainedScope
@ViewScope
@ApplicationScope
@UserScope
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:core:network
OkHttpClient
:features:composer
:subsystems:tweets
:twitter:media
@RetainedScope
@ViewScope
@UserScope
@ApplicationScope
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:core:network
OkHttpClient
:features:composer
:subsystems:tweets
:twitter:media
@RetainedScope
@ViewScope
@ApplicationScope
@UserScope
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:core:network
:features:composer
:subsystems:tweets
:twitter:media
@RetainedScope
@ViewScope
@ApplicationScope
@UserScope
ComposerNotifHandler
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:core:network
:features:composer
:subsystems:tweets
:twitter:media
@RetainedScope
@ViewScope
@ApplicationScope
@UserScope
ComposerNotifHandler
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:core:network
:features:composer
:subsystems:tweets
:twitter:media
@RetainedScope
@ViewScope
@ApplicationScope
@UserScope
M M M
M
M
M
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:core:network
:features:composer
:subsystems:tweets
:twitter:media
@RetainedScope
@ViewScope
@ApplicationScope
@UserScope
M
M M
M
M
M
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Ideal Location
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App wide graphs definitions belong in
the top gradle module.
Ideal Location
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Graphs can be large!
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@Component
@ApplicationScope
interface ApplicationObjectGraph
}
fun composerLauncher(): ComposerLauncher
fun composerNotificationHandler(): ComposerNotifHandler
{
])
(modules = [ComposerAppModule::class
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@Component
@ApplicationScope
interface ApplicationObjectGraph
}
fun composerLauncher(): ComposerLauncher
fun composerNotificationHandler(): ComposerNotifHandler
fun tweetsRepository(): TweetsRepository
fun tweetsDataSource(): TweetsDataSource
fun imageLoader(): ImageLoader
{
, TweetRepositoryAppModule::cl
(modules = [ComposerAppModule::class
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fun okHttpClient(): OkHttpClient
fun twitterApiService(): TwitterApiService
@Component
@ApplicationScope
interface ApplicationObjectGraph
fun composerLauncher(): ComposerLauncher
fun composerNotificationHandler(): ComposerNotifHandler
fun tweetsRepository(): TweetsRepository
fun tweetsDataSource(): TweetsDataSource
fun imageLoader(): ImageLoader
{
fun loginController(): LoginController
fun loginAssistController(): LoginAssistController
fun appEventTracker(): AppEventTracker
fun installationReferrer(): InstallationReferrer
fun jobManager(): JobManager
fun playServicesUtil(): PlayServicesUtil
fun httpRequestController(): HttpRequestController
fun registrableHeadsetPlugReceiver(): RegistrableHeadsetPlugReceiver
, TweetRepositoryAppModule::cl
(modules = [ComposerAppModule::class
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fun okHttpClient(): OkHttpClient
fun twitterApiService(): TwitterApiService
@Component
@ApplicationScope
interface ApplicationObjectGraph
fun composerLauncher(): ComposerLauncher
fun composerNotificationHandler(): ComposerNotifHandler
fun tweetsRepository(): TweetsRepository
fun tweetsDataSource(): TweetsDataSource
fun imageLoader(): ImageLoader
{
fun loginController(): LoginController
fun loginAssistController(): LoginAssistController
fun appEventTracker(): AppEventTracker
fun installationReferrer(): InstallationReferrer
fun jobManager(): JobManager
fun playServicesUtil(): PlayServicesUtil
fun httpRequestController(): HttpRequestController
fun registrableHeadsetPlugReceiver(): RegistrableHeadsetPlugReceiver
, TweetRepositoryAppModule::cl
(modules = [ComposerAppModule::class
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fun okHttpClient(): OkHttpClient
fun twitterApiService(): TwitterApiService
@Component
@ApplicationScope
interface ApplicationObjectGraph
fun composerLauncher(): ComposerLauncher
fun composerNotificationHandler(): ComposerNotifHandler
fun tweetsRepository(): TweetsRepository
fun tweetsDataSource(): TweetsDataSource
fun imageLoader(): ImageLoader
{
fun loginController(): LoginController
fun loginAssistController(): LoginAssistController
fun appEventTracker(): AppEventTracker
fun installationReferrer(): InstallationReferrer
fun jobManager(): JobManager
fun playServicesUtil(): PlayServicesUtil
fun httpRequestController(): HttpRequestController
fun registrableHeadsetPlugReceiver(): RegistrableHeadsetPlugReceiver
, TweetRepositoryAppModule::cl
(modules = [ComposerAppModule::class
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Subgraphs
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Subgraphs
Slices of an Object Graph
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@Component
@ApplicationScope
interface ApplicationObjectGraph {
}
fun okHttpClient(): OkHttpClient
fun twitterApiService(): TwitterApiService
fun composerLauncher(): ComposerLauncher
fun composerNotificationHandler(): ComposerNotifHandler
fun tweetsRepository(): TweetsRepository
fun tweetsDataSource(): TweetsDataSource
fun imageLoader(): ImageLoader
:app:twitter
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:
@Component
@ApplicationScope
interface ApplicationObjectGraph
{
}
fun okHttpClient(): OkHttpClient
fun twitterApiService(): TwitterApiService
fun composerLauncher(): ComposerLauncher
fun composerNotificationHandler(): ComposerNotifHandler
fun tweetsRepository(): TweetsRepository
fun tweetsDataSource(): TweetsDataSource
fun imageLoader(): ImageLoader
ComposerAppSubgraph
interface ComposerAppSubgraph {
}
:app:twitter
:features:composer
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:
@Component
@ApplicationScope
interface ApplicationObjectGraph
{
}
fun okHttpClient(): OkHttpClient
fun twitterApiService(): TwitterApiService
fun tweetsRepository(): TweetsRepository
fun tweetsDataSource(): TweetsDataSource
fun imageLoader(): ImageLoader
ComposerAppSubgraph
:app:twitter
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@Component
@ApplicationScope
interface ApplicationObjectGraph
,
:
{
}
fun okHttpClient(): OkHttpClient
fun twitterApiService(): TwitterApiService
fun tweetsRepository(): TweetsRepository
fun tweetsDataSource(): TweetsDataSource
fun imageLoader(): ImageLoader
ComposerAppSubgraph
interface TweetRepositoryAppSubgraph {
}
TweetRepositoryAppSubgraph
:app:twitter
:subsystems:tweets
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@Component
@ApplicationScope
interface ApplicationObjectGraph
,
:
{
}
fun okHttpClient(): OkHttpClient
fun twitterApiService(): TwitterApiService
fun imageLoader(): ImageLoader
ComposerAppSubgraph
TweetRepositoryAppSubgraph
:app:twitter
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@Component
@ApplicationScope
interface ApplicationObjectGraph
,
:
{
}
fun okHttpClient(): OkHttpClient
fun twitterApiService(): TwitterApiService
fun imageLoader(): ImageLoader
ComposerAppSubgraph
TweetRepositoryAppSubgraph
interface MediaAppSubgraph {
}
MediaAppSubgraph
,
:app:twitter
:twitter:media
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@Component
@ApplicationScope
interface ApplicationObjectGraph
,
:
{
}
fun okHttpClient(): OkHttpClient
fun twitterApiService(): TwitterApiService
ComposerAppSubgraph
TweetRepositoryAppSubgraph
MediaAppSubgraph
,
:app:twitter
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@Component
@ApplicationScope
interface ApplicationObjectGraph
,
:
fun okHttpClient(): OkHttpClient
fun twitterApiService(): TwitterApiService
ComposerAppSubgraph
TweetRepositoryAppSubgraph
MediaAppSubgraph
,
interface CoreNetworkAppSubgraph {
}
CoreNetworkAppSubgraph
,
:core:network
:app:twitter
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@Component
@ApplicationScope
interface ApplicationObjectGraph
,
:
ComposerAppSubgraph
TweetRepositoryAppSubgraph
MediaAppSubgraph
,
CoreNetworkAppSubgraph
,
:app:twitter
ApplicationObjectGraph
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:core:network
:features:composer
:subsystems:tweets
:twitter:media
TweetRepositoryAppSubgraph
MediaAppSubgraph
CoreNetworkAppSubgraph
ApplicationObjectGraph
ComposerAppSubgraph
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:core:network
:features:composer
:subsystems:tweets
:twitter:media
TweetRepositoryAppSubgraph
MediaAppSubgraph
CoreNetworkAppSubgraph
ApplicationObjectGraph
ComposerAppSubgraph
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ApplicationObjectGraph
UserObjectGraph
Multiple Retained
and ViewObjectGraphs
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ApplicationObjectGraph
UserObjectGraph
Multiple Retained
and ViewObjectGraphs
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Big monolithic graphs
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Big monolithic graphs
Scatter the definitions of the object graphs into
subgraphs that can live in the gradle modules
where the bindings are actually defined.
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How to instantiate your graphs?
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component =
.application(this)
.build()
class MyApplication : Application {
private lateinit var component: ApplicationObjectGraph
override fun onCreate() {
}
super.onCreate()
}
DaggerApplicationObjectGraph.builder()
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component =
.application(this)
.build()
class MyApplication : Application {
private lateinit var component: ApplicationObjectGraph
override fun onCreate() {
}
super.onCreate()
}
DaggerApplicationObjectGraph.builder()
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Dagger.getObjectGraphBuilder()
component =
.application(this)
.build()
class MyApplication : Application {
private lateinit var component: ApplicationObjectGraph
override fun onCreate() {
}
super.onCreate()
}
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fun getObjectGraphBuilder(builderClass: Class): B
}
}
class Dagger {
companion object {
inline fun getObjectGraphBuilder(): B =
getObjectGraphBuilder(B::class.java)
}
{
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fun getObjectGraphBuilder(builderClass: Class): B
}
}
class Dagger {
companion object {
inline fun getObjectGraphBuilder(): B =
getObjectGraphBuilder(B::class.java)
}
{
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if (!builderClass.isAnnotationPresent(Component.Builder::class.java)) {
throw IllegalArgumentException("Not a component builder class: $builderClass")
}
val componentClass = builderClass.enclosingClass
?: throw IllegalStateException("Component builder is not enclosed in a component.")
val generatedDaggerClassName = getDaggerComponentImplementationClassName(componentClass)
val generatedObjectGraphClass = ReflectionUtils.loadClass(generatedDaggerClassName)
?: throw IllegalStateException("Generated Dagger class can't be found: $generatedDagge
val builderMethod = ReflectionUtils.getMethod(generatedObjectGraphClass, "builder")
?: throw IllegalStateException("The Dagger component generated class does not contain
return ReflectionUtils.invokeMethod(builderMethod, null)
?: throw IllegalStateException("The builder() method returned null.")
fun getObjectGraphBuilder(builderClass: Class): B
}
}
class Dagger {
companion object {
inline fun getObjectGraphBuilder(): B =
getObjectGraphBuilder(B::class.java)
}
{
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if (!builderClass.isAnnotationPresent(Component.Builder::class.java)) {
throw IllegalArgumentException("Not a component builder class: $builderClass")
}
val componentClass = builderClass.enclosingClass
?: throw IllegalStateException("Component builder is not enclosed in a component.")
val generatedDaggerClassName = getDaggerComponentImplementationClassName(componentClass)
val generatedObjectGraphClass = ReflectionUtils.loadClass(generatedDaggerClassName)
?: throw IllegalStateException("Generated Dagger class can't be found: $generatedDagge
val builderMethod = ReflectionUtils.getMethod(generatedObjectGraphClass, "builder")
?: throw IllegalStateException("The Dagger component generated class does not contain
return ReflectionUtils.invokeMethod(builderMethod, null)
?: throw IllegalStateException("The builder() method returned null.")
fun getObjectGraphBuilder(builderClass: Class): B
}
}
class Dagger {
companion object {
inline fun getObjectGraphBuilder(): B =
getObjectGraphBuilder(B::class.java)
}
TL;DR
Use reflection once to find and instantiate
the graph’s Component.Builder
{
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if (!builderClass.isAnnotationPresent(Component.Builder::class.java)) {
throw IllegalArgumentException("Not a component builder class: $builderClass")
}
val componentClass = builderClass.enclosingClass
?: throw IllegalStateException("Component builder is not enclosed in a component.")
val generatedDaggerClassName = getDaggerComponentImplementationClassName(componentClass)
val generatedObjectGraphClass = ReflectionUtils.loadClass(generatedDaggerClassName)
?: throw IllegalStateException("Generated Dagger class can't be found: $generatedDagge
val builderMethod = ReflectionUtils.getMethod(generatedObjectGraphClass, "builder")
?: throw IllegalStateException("The Dagger component generated class does not contain
return ReflectionUtils.invokeMethod(builderMethod, null)
?: throw IllegalStateException("The builder() method returned null.")
fun getObjectGraphBuilder(builderClass: Class): B
}
}
class Dagger {
companion object {
inline fun getObjectGraphBuilder(): B =
getObjectGraphBuilder(B::class.java)
}
Don’t worry!
We will share the code in GitHub!
{
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Referencing generated code
DaggerApplicationObjectGraph.builder()
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Referencing generated code
Use reflection once to grab the root object
graph builder.
Dagger.getObjectGraphBuilder()
DaggerApplicationObjectGraph.builder()
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How to access graphs at the
top from intermediate layers?
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ApplicationObjectGraph
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ApplicationObjectGraph
:twitter:media
ImageUploader
L
LegacyActivity
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:twitter:media
L
ImageUploader
LegacyActivity
ApplicationObjectGraph
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:twitter:media
MediaAppSubgraph
L
LegacyActivity
ApplicationObjectGraph
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object ApplicationObjectGraphProvider {
var graphProvider: Any?
}
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component = Dagger.getObjectGraphBuilder()
.application(this)
.build()
class MyApplication : Application {
private lateinit var component: ApplicationObjectGraph
override fun onCreate() {
}
super.onCreate()
}
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component = Dagger.getObjectGraphBuilder()
.application(this)
.build()
class MyApplication : Application {
private lateinit var component: ApplicationObjectGraph
override fun onCreate() {
}
super.onCreate()
}
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super.onCreate()
}
ApplicationObjectGraphProvider.graphProvider =
Dagger.getObjectGraphBuilder()
.application(this)
.build()
class MyApplication : Application {
override fun onCreate() {
}
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ApplicationObjectGraph
ApplicationObjectGraphProvider
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ApplicationObjectGraph
ApplicationObjectGraphProvider
:twitter:media
L
ImageUploader
LegacyActivity
MediaAppSubgraph
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(ApplicationObjectGraphProvider.graphProvider as MediaAppSubgraph).imageUploader()
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object ApplicationObjectGraphProvider {
}
fun getSubgraph(clazz: Class): T
var graphProvider: Any?
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object ApplicationObjectGraphProvider {
}
fun getSubgraph(clazz: Class): T
var graphProvider: Any?
{
return clazz.cast(graphProvider)
}
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fun imageUploader(): ImageUploader
interface MediaAppSubgraph {
}
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fun imageUploader(): ImageUploader
interface MediaAppSubgraph {
}
companion object {
fun get(): MediaAppSubgraph {
return ApplicationObjectGraphProvider.graphProvider
.getSubgraph(MediaAppSubgraph::class.java)
}
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val uploader = MediaAppSubgraph.get().imageUploader()
fun imageUploader(): ImageUploader
interface MediaAppSubgraph {
}
companion object {
fun get(): MediaAppSubgraph {
return ApplicationObjectGraphProvider.graphProvider
.getSubgraph(MediaAppSubgraph::class.java)
}
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val uploader = MediaAppSubgraph.get().imageUploader()
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Grabbing objects from Dagger w/o visibility
MediaAppSubgraph
L
LegacyActivity
ApplicationObjectGraph
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Grabbing objects from Dagger w/o visibility
Wrap your Application and User graphs in
providers that can be statically obtained, and
add a way to extract subgraphs from them.
ApplicationObjectGraphProvider
UserObjectGraphProvider
MediaAppSubgraph
L
LegacyActivity
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How would that work in testing?
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object ApplicationObjectGraphProvider {
}
var graphProvider: Any?
private val mapping: Map, Any> = mutableMapOf()
fun overrideSubgraph(clazz: Class, subgraph: T) {
mapping[clazz] = subgraph
}
fun getSubgraph(clazz: Class): T {
if (mapping.containsKey(clazz)) return clazz.cast(mapping[clazz])
return clazz.cast(graphProvider)
}
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object ApplicationObjectGraphProvider {
}
var graphProvider: Any?
private val mapping: Map, Any> = mutableMapOf()
fun overrideSubgraph(clazz: Class, subgraph: T) {
mapping[clazz] = subgraph
}
fun getSubgraph(clazz: Class): T {
if (mapping.containsKey(clazz)) return clazz.cast(mapping[clazz])
return clazz.cast(graphProvider)
}
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How to decouple features?
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How to decouple features?
The app navigation case
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No content
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ComposerActivity
MainActivity
DMActivity
TweetDetailActivity
C
D
M
TD
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ComposerActivity
MainActivity
DMActivity
TweetDetailActivity
C D M TD
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ComposerActivity
MainActivity
DMActivity
TweetDetailActivity
C D M TD
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ComposerActivity
MainActivity
DMActivity
TweetDetailActivity
C D M TD
Circular Dependency!
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ComposerActivity
MainActivity
TweetDetailActivity
C D M TD
DMActivity
:subsystems:navigation
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ComposerActivity
MainActivity
TweetDetailActivity
C D M TD
Intent().putExtra(…)
DMActivity
:subsystems:navigation
C D M TD
C D M TD
Intent factories
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ComposerActivity
MainActivity
TweetDetailActivity
C D M TD
DMActivity
:subsystems:navigation
C D M TD
Intent factories
ActivityArgs
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ComposerActivity
MainActivity
TweetDetailActivity
C D M TD
DMActivity
:subsystems:navigation
TD
M
D
C
ActivityArgs
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ComposerActivity
MainActivity
TweetDetailActivity
C D M TD
DMActivity
:subsystems:navigation
TD
M
D
C
ActivityArgs
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interface ActivityArgs {
fun toIntent(context: Context, clazz: Class): Intent
}
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override fun toIntent(context: Context, clazz: Class): {
.apply {
putExtra("user_id", uid)
putExtra("text", text)
}
}
interface ActivityArgs {
fun toIntent(context: Context, clazz: Class): Intent
}
data class ComposerArgs(val uid: Long, val text: String): ActivityArgs {
}
return Intent(context, clazz)
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override fun toIntent(context: Context, clazz: Class): {
.apply {
putExtra("user_id", uid)
putExtra("text", text)
}
}
interface ActivityArgs {
fun toIntent(context: Context, clazz: Class): Intent
}
data class ComposerArgs(val uid: Long, val text: String): ActivityArgs {
}
return Intent(context, clazz)
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Service Discovery
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Service Discovery
Multibindings
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C
D
TD
ComposerArgs
TweetDetailArgs
DMArgs
:features:tweetdetail
:features:dm
:features:composer
@Multibinds
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C D TD
ComposerArgs
TweetDetailArgs
DMArgs
:features:tweetdetail
:features:dm
:features:composer
@Multibinds
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C D TD
ComposerArgs
TweetDetailArgs
DMArgs
:features:tweetdetail
:features:dm
:features:composer
@Multibinds
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C D TD
ComposerArgs
TweetDetailArgs
DMArgs
:features:tweetdetail
:features:dm
:features:composer
Map, Class>
C D TD
ComposerActivity
DMActivity
TweetDetailActivity
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@Module
object ComposerModule {
@Provides
@ApplicationScope
fun provideActivityClass: Class {
}
}
:features:composer
@ActivityArgsKey(ComposerArgs::class)
@IntoMap
return ComposerActivity::class.java
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@Module
object ComposerModule {
@Provides
@ApplicationScope
fun provideActivityClass: Class {
}
}
:features:composer
@ActivityArgsKey(ComposerArgs::class)
@IntoMap
return ComposerActivity::class.java
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@Module
object ComposerModule {
@Provides
@ApplicationScope
fun provideActivityClass: Class {
}
}
:features:composer
@ActivityArgsKey(ComposerArgs::class)
@IntoMap
return ComposerActivity::class.java
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@Module
object ComposerModule {
@Provides
@ApplicationScope
fun provideActivityClass: Class {
}
}
:features:composer
@ActivityArgsKey(ComposerArgs::class)
@IntoMap
return ComposerActivity::class.java
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@ApplicationScope
class ActivityStarter @Inject constructor(
)
private val activityMap:
Map, Class>
{
fun startActivity(context: Context, args: ActivityArgs) {
}
}
val intent = args.toIntent(context, activityMap[args.javaClass])
context.startActivity(intent)
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@ApplicationScope
class ActivityStarter @Inject constructor(
)
{
fun startActivity(context: Context, args: ActivityArgs) {
}
}
val intent = args.toIntent(context, activityMap[args.javaClass])
context.startActivity(intent)
private val activityMap:
Map, Class>
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{
fun startActivity(context: Context, args: ActivityArgs) {
}
}
@ApplicationScope
class ActivityStarter @Inject constructor(
)
val intent = args.toIntent(context, activityMap[args.javaClass])
context.startActivity(intent)
private val activityMap:
Map, Class>
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{
fun startActivity(context: Context, args: ActivityArgs) {
}
}
@ApplicationScope
class ActivityStarter @Inject constructor(
)
val intent = args.toIntent(context, activityMap[args.javaClass])
context.startActivity(intent)
private val activityMap:
Map, Class>
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C TD
Start an Activity we can’t see at compile time
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C D TD
C D TD
Start an Activity we can’t see at compile time
At compile time you might not see everything,
but at runtime it is all there.
Let’s use Multibindings to aggregate references
at compile time and resolve them at runtime.
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No content
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Initializers
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Notification Handlers
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Deeplink Handlers
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No content
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No content
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Subgraphs
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Subgraphs
are not atomic units
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S
ApplicationObjectGraph
S
S
S
S
S
S
S
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S
ApplicationObjectGraph
M
S
M
S
M
S
M
S
M
S
M
S
M
S
M
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S
ApplicationObjectGraph
M
S
M
S
M
S
M
S
S
M
S
M
S
M
@Component(modules = [
ComposerAppModule::class,
TweetDetailAppModule::class,
HomeAppModule::class,
ExploreAppModule::class,
CoreAppModule::class,
CoreNetworkAppModule::class,
MediaAppModule::class,
VideoAppModule::class,
NavigationAppModule::class,
LoggingAppModule::class,
TimelineAppModule::class,
… and on and on and on
])
@ApplicationScope
interface ApplicationObjectGraph:
M
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ApplicationObjectGraph
M
M
M
M
M
M
M
M
TimelineAppModule::class,
… and on and on and on
])
@ApplicationScope
interface ApplicationObjectGraph:
InitializationSubgraph,
ComposerAppSubgraph,
TweetDetailAppSubgraph,
HomeAppSubgraph,
ExploreAppSubgraph,
CoreAppSubgraph,
CoreNetworkAppSubgraph,
MediaAppSubgraph,
VideoAppSubgraph,
NavigationAppSubgraph,
… and on and on and on
S
S
S
S
S
S
S
S
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S
M
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@Component(modules = [
… and on and on and on
])
@ApplicationScope
interface ApplicationObjectGraph:
InitializationSubgraph,
TweetDetailAppSubgraph,
@Component(modules = [
… and on and on and on
])
@ApplicationScope
interface ApplicationObjectGraph:
InitializationSubgraph,
MapSubgraph,
S
M
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@Component(modules = [
BroadcastAppModule::class,
… and on and on and on
])
@ApplicationScope
interface ApplicationObjectGraph:
InitializationSubgraph,
BroadcastAppSubgraph,
TweetDetailAppSubgraph,
@Component(modules = [
BroadcastAppModule::class,
… and on and on and on
])
@ApplicationScope
interface ApplicationObjectGraph:
InitializationSubgraph,
BroadcastAppSubgraph,
MapSubgraph,
S
M
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No content
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{
fun broadcastController(): BroadcastController
}
@Module
{
@Binds
@ApplicationScope
fun bindBcastController(impl: BroadcastControllerImpl):
BroadcastController
}
object BroadcastAppModule
interface BroadcastAppSubgraph
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interface BroadcastAppSubgraph {
fun broadcastController(): BroadcastController
}
@Subgraph
@Module
{
@Binds
@ApplicationScope
fun bindBcastController(impl: BroadcastControllerImpl):
BroadcastController
}
object BroadcastAppModule
interface BroadcastAppSubgraph
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@ApplicationScope
interface BroadcastAppSubgraph {
fun broadcastController(): BroadcastController
}
@Subgraph
@Module
{
@Binds
@ApplicationScope
fun bindBcastController(impl: BroadcastControllerImpl):
BroadcastController
}
object BroadcastAppModule
interface BroadcastAppSubgraph
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@ApplicationScope
interface BroadcastAppSubgraph {
fun broadcastController(): BroadcastController
}
@Subgraph
@Subgraph(modules = [BroadcastAppModule::class])
@Module
{
@Binds
@ApplicationScope
fun bindBcastController(impl: BroadcastControllerImpl):
BroadcastController
}
object BroadcastAppModule
interface BroadcastAppSubgraph
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@ApplicationScope
interface ApplicationObjectGraph :
BroadcastAppSubgraph, InitializationSubgraph, ...
(modules = [BroadcastAppModule::class, ...])
@Component
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@ApplicationScope
interface ApplicationObjectGraph :
BroadcastAppSubgraph, InitializationSubgraph, ...
(modules = [BroadcastAppModule::class, ...])
@Component
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@ApplicationScope
interface ApplicationObjectGraph :
BroadcastAppSubgraph, InitializationSubgraph, ...
@ObjectGraph
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@UserScope
interface UserObjectGraph :
UserManagerSubgraph, TweetRepository, ...
(modules = [UserManagerModule::class, ...])
@ApplicationScope
interface ApplicationObjectGraph :
BroadcastAppSubgraph, InitializationSubgraph, ...
@ObjectGraph
@Subcomponent
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@UserScope
interface UserObjectGraph :
UserManagerSubgraph, TweetRepository, ...
(modules = [UserManagerModule::class, ...])
@ApplicationScope
interface ApplicationObjectGraph :
BroadcastAppSubgraph, InitializationSubgraph, ...
@ObjectGraph
@Subcomponent
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@UserScope
interface UserObjectGraph :
UserManagerSubgraph, TweetRepository, ...
@ApplicationScope
interface ApplicationObjectGraph :
BroadcastAppSubgraph, InitializationSubgraph, ...
@ObjectGraph
@ObjectGraph
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@ObjectGraph @Subgraph
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Annotation Processor
@ObjectGraph @Subgraph
@Component
@Subcomponent
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@ObjectGraph
@Subgraph
Annotation Processor
@Component
@Subcomponent
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Annotation Processor
@ObjectGraph
@Subgraph
@Component
@Subcomponent
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Fully Dagger Compatible
Annotation Processor
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Subgraphs
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Subgraphs
are not encapsulated
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S
S
S
S
S S
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S
S
S
S
S S
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S S
S
S
S S
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S
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S
@ApplicationScope
interface BroadcastAppSubgraph {
fun broadcastController(): BroadcastController
}
@Subgraph(modules = [BroadcastAppModule::class])
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@Subgraph(
subgraphDependencies = [
CoreNetworkSubgraph::class,
VideoPlayerSubgraph::class
])
S
@ApplicationScope
interface BroadcastAppSubgraph {
fun broadcastController(): BroadcastController
}
@Subgraph
@Subgraph(modules = [BroadcastAppModule::class],
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S
ApplicationObjectGraph
S
S
S
S
S
S
S
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S
ApplicationObjectGraph
S
S
S
S
S
S
S
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S
ApplicationObjectGraph
S
S
S
S
S
S
S
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Subgraphs
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Subgraphs
are not self documenting
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Subgraphs
are not self documenting
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@Subgraph(
subgraphDependencies = [
CoreNetworkSubgraph::class,
VideoPlayerSubgraph::class
])
@ApplicationScope
interface BroadcastAppSubgraph {
fun broadcastController(): BroadcastController
}
@Subgraph
@Subgraph(modules = [BroadcastAppModule::class],
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@Subgraph(
subgraphDependencies = [
CoreNetworkSubgraph::class,
VideoPlayerSubgraph::class
])
@ApplicationScope
interface BroadcastAppSubgraph {
fun broadcastController(): BroadcastController
}
@Subgraph
@Subgraph(modules = [BroadcastAppModule::class],
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@Subgraph(
subgraphDependencies = [
CoreNetworkSubgraph::class,
VideoPlayerSubgraph::class
])
@ApplicationScope
interface BroadcastAppSubgraph {
fun broadcastController(): BroadcastController
}
@Subgraph
@Subgraph(modules = [BroadcastAppModule::class],
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@Subgraph(
subgraphDependencies = [
CoreNetworkSubgraph::class,
VideoPlayerSubgraph::class
])
@ApplicationScope
interface BroadcastAppSubgraph {
fun broadcastController(): BroadcastController
}
@Subgraph
@Subgraph(modules = [BroadcastAppModule::class],
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Graphs
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Graphs
are hard to maintain
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@ObjectGraph
@ApplicationScope
interface ApplicationObjectGraph:
InitializationSubgraph,
BroadcastAppSubgraph,
TweetDetailAppSubgraph,
HomeAppSubgraph,
ExploreAppSubgraph,
CoreAppSubgraph,
CoreNetworkAppSubgraph,
MediaAppSubgraph,
VideoPlayerSubgraph,
NavigationAppSubgraph,
TweetUploadAppSubgraph,
PerformanceMetricsAppSubgraph,
DMAppSubgraph,
JSONModelsAppSubgraph,
DynamicModulesAppSubgraph,
NotificationsAppSubgraph,
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@ObjectGraph
@ApplicationScope
interface ApplicationObjectGraph:
InitializationSubgraph,
BroadcastAppSubgraph,
TweetDetailAppSubgraph,
HomeAppSubgraph,
ExploreAppSubgraph,
CoreAppSubgraph,
CoreNetworkAppSubgraph,
MediaAppSubgraph,
VideoPlayerSubgraph,
NavigationAppSubgraph,
TweetUploadAppSubgraph,
PerformanceMetricsAppSubgraph,
DMAppSubgraph,
JSONModelsAppSubgraph,
DynamicModulesAppSubgraph,
NotificationsAppSubgraph,
This is actually insane
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Annotation Processor
@ObjectGraph
@ApplicationScope
interface ApplicationObjectGraph:
InitializationSubgraph,
BroadcastAppSubgraph,
TweetDetailAppSubgraph,
HomeAppSubgraph,
ExploreAppSubgraph,
CoreAppSubgraph,
CoreNetworkAppSubgraph,
MediaAppSubgraph,
VideoPlayerSubgraph,
NavigationAppSubgraph,
TweetUploadAppSubgraph,
PerformanceMetricsAppSubgraph,
DMAppSubgraph,
JSONModelsAppSubgraph,
DynamicModulesAppSubgraph,
NotificationsAppSubgraph,
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Annotation Processor
@ObjectGraph
@ApplicationScope
interface ApplicationObjectGraph:
InitializationSubgraph,
BroadcastAppSubgraph,
TweetDetailAppSubgraph,
HomeAppSubgraph,
ExploreAppSubgraph,
CoreAppSubgraph,
CoreNetworkAppSubgraph,
MediaAppSubgraph,
VideoPlayerSubgraph,
NavigationAppSubgraph,
TweetUploadAppSubgraph,
PerformanceMetricsAppSubgraph,
DMAppSubgraph,
JSONModelsAppSubgraph,
DynamicModulesAppSubgraph,
NotificationsAppSubgraph,
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@ObjectGraph
@ApplicationScope
interface ApplicationObjectGraph
Annotation Processor
Automatic Discovery
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S
ApplicationObjectGraph
S
S
S
S
S
S
S
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S
ApplicationObjectGraph
S
S
S
S
S
S
S
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Subgraphs
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Subgraphs
are not reusable
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CoreNetworkSubgraph
OkHttpClient
Cache
Set
CoreNetworkSubgraph
:core:network
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PeriscopeNetworkSubgraph
:periscope:network
CoreNetworkSubgraph
OkHttpClient
Cache
Set
CoreNetworkSubgraph
:core:network
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CoreNetworkSubgraph
OkHttpClient
Cache
Set
CoreNetworkSubgraph
:core:network
PeriscopeNetworkSubgraph
:periscope:network
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open class CoreNetworkSubgraph {
fun okHttpClient(): OkHttpClient = …
fun interceptors(): Set = …
}
fun cache(): Cache = Cache()
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class PeriscopeNetworkSubgraph : CoreNetworkSubgraph {
override fun cache(): Cache = PeriscopeCachePolicy()
}
open fun cache(): Cache = Cache()
open class CoreNetworkSubgraph {
fun okHttpClient(): OkHttpClient = …
fun interceptors(): Set = …
}
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@Subgraph(module = [CoreNetworkModule::class])
@Open
interface CoreNetworkSubgraph {
fun okHttpClient(): OkHttpClient
@Open fun cache(): Cache
fun interceptors(): Set
}
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@Subgraph(module = [CoreNetworkModule::class])
@Open
interface CoreNetworkSubgraph {
fun okHttpClient(): OkHttpClient
@Open fun cache(): Cache
fun interceptors(): Set
}
@Subgraph
interface PeriscopeNetworkSubgraph : CoreNetworkSubgraph {
@Override @Binds fun bindCache(cache: PeriscopeCache): Cache
}
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Subgraphs
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Subgraphs
don’t support inversion of dependencies
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interface DatabaseSubgraph {
fun migrationManager(): MigrationManager
}
fun schema(): Schema
@Subgraph
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interface DatabaseSubgraph {
fun migrationManager(): MigrationManager
}
fun schema(): Schema
@Subgraph
@Abstract
@Abstract
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interface DatabaseSubgraph {
fun migrationManager(): MigrationManager
}
fun schema(): Schema
@Subgraph
@Abstract
@Abstract
@Subgraph
interface TwitterDatabaseSubgraph : DatabaseSubgraph {
@Binds fun schema(bound: TwitterSchema): Schema
}
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And more!
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And more!
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And more!
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And more!
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Annotation Processor
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Scythe
Scythe
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Scythe
OOP concepts for DI
IDE support
Better build times
Binding overrides
Modular scalability Self documentation
Reusability
Automatic discovery
Completeness validation
Factory bindings
Assisted Injection
Compatible with Dagger
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Scythe
Open-source launch for everybody in 2020
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@CesarDielo
César
@mrmans0n
Nacho
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@CesarDielo
César
@mrmans0n
Nacho
Thank you!
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