five android architecture
TRANSCRIPT
Intro to Five Architecture
29.09.2016@Five #[email protected]
Or zero to clean….
Tomislav Homan, Five
Overview● Earlier fails
● General Clean Architecture
● Clean Adjusted for Android
● Is it better?
● No code, just philosophy
Software Architecture ● “Intellectually graspable” abstraction of a complex system (wiki)
● (which helps us plan, design and construct software)
Software Architecture ● “Intellectually graspable” abstraction of a complex system (wiki)
● Multitude of stakeholders
● Separation of concerns - one reason to change
● Run away from the real world (Android, DB, Internet)
● Testability
● SRP + Testability + … = Maintainability, Scalability, etc...
The olden times - God activitypublic final class UsersActivity extends ListActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
//...
new ListUsers().execute();
}
private final class ListUsers extends AsyncTask<Void, Void, Void> {
@Override
protected Void doInBackground(Void... voids) {
// final SQLiteOpenHelper sqLiteOpenHelper = ...
// JsonObjectRequest jsObjRequest = new JsonObjectRequest
// (Request.Method.GET, url, null, new Response.Listener<JSONObject>() {
// MySingleton.getInstance(this).addToRequestQueue(jsObjRequest);
// showData(user);
return null;
}
}
}
The olden times - God activitypublic final class UsersActivity extends ListActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
//...
new ListUsers().execute();
}
private final class ListUsers extends AsyncTask<Void, Void, Void> {
@Override
protected Void doInBackground(Void... voids) {
// final SQLiteOpenHelper sqLiteOpenHelper = ...
// JsonObjectRequest jsObjRequest = new JsonObjectRequest
// (Request.Method.GET, url, null, new Response.Listener<JSONObject>() {
// MySingleton.getInstance(this).addToRequestQueue(jsObjRequest);
// showData(user);
return null;
}
}
}
The olden times - God activitypublic final class UsersActivity extends ListActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
//...
new ListUsers().execute();
}
private final class ListUsers extends AsyncTask<Void, Void, Void> {
@Override
protected Void doInBackground(Void... voids) {
// final SQLiteOpenHelper sqLiteOpenHelper = ...
// JsonObjectRequest jsObjRequest = new JsonObjectRequest
// (Request.Method.GET, url, null, new Response.Listener<JSONObject>() {
// MySingleton.getInstance(this).addToRequestQueue(jsObjRequest);
// showData(user);
return null;
}
}
}
NOT testable
The olden times - God activitypublic final class UsersActivity extends ListActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
//...
new ListUsers().execute();
}
private final class ListUsers extends AsyncTask<Void, Void, Void> {
@Override
protected Void doInBackground(Void... voids) {
// final SQLiteOpenHelper sqLiteOpenHelper = ...
// JsonObjectRequest jsObjRequest = new JsonObjectRequest
// (Request.Method.GET, url, null, new Response.Listener<JSONObject>() {
// MySingleton.getInstance(this).addToRequestQueue(jsObjRequest);
// showData(user);
return null;
}
}
}
NOT testable
Stakeholders?
The olden times - God activitypublic final class UsersActivity extends ListActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
//...
new ListUsers().execute();
}
private final class ListUsers extends AsyncTask<Void, Void, Void> {
@Override
protected Void doInBackground(Void... voids) {
// final SQLiteOpenHelper sqLiteOpenHelper = ...
// JsonObjectRequest jsObjRequest = new JsonObjectRequest
// (Request.Method.GET, url, null, new Response.Listener<JSONObject>() {
// MySingleton.getInstance(this).addToRequestQueue(jsObjRequest);
// showData(user);
return null;
}
}
}
NOT testable
Stakeholders?
SRP?
The olden times - God activitypublic final class UsersActivity extends ListActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
//...
new ListUsers().execute();
}
private final class ListUsers extends AsyncTask<Void, Void, Void> {
@Override
protected Void doInBackground(Void... voids) {
// final SQLiteOpenHelper sqLiteOpenHelper = ...
// JsonObjectRequest jsObjRequest = new JsonObjectRequest
// (Request.Method.GET, url, null, new Response.Listener<JSONObject>() {
// MySingleton.getInstance(this).addToRequestQueue(jsObjRequest);
// showData(user);
return null;
}
}
}
NOT testable
Stakeholders?
SRP? Mixed with
Android!
The olden times - MVP● Better
The olden times - MVP● Better
The olden times - MVP● Better
The olden times - MVP● Better
SRP
The olden times - MVP● Better
SRP Testable-ish
The olden times - MVP● Better
SRP Testable-ish
Stakeholders?
The olden times - MVP● Better
SRP Testable-ish
Mixed with
Android!Stakeholders?
The olden times - MVP + Managers● Sorta OK
Manager this
Manager that
The olden times - MVP + Managers● Sorta OK
Manager this
Manager that
SRP - meh ok
The olden times - MVP + Managers● Sorta OK
Manager this
Manager that
SRP - meh ok
Stakeholders
The olden times - MVP + Managers● Sorta OK
Manager this
Manager that
SRP - meh ok
Stakeholders
Mixed with
Android!
The olden times - MVP + Managers● Sorta OK
Manager this
Manager that
SRP - meh ok
Stakeholders
Mixed with
Android!Testable-ish
Tend to be HUGE!!!
The Clean Architecture
The Clean ArchitectureOnion
The Clean Architecture
Ports and Adapters
The Clean Architecture
● Dependency rule
● Abstraction
● Communication between layers
Dependency rule
Dependency rule
Dependency rule
Dependency rule
Dependency rule
Abstraction
Abstraction
Abstraction
All dependencies go to the database
Core of the app
3 tier Clean
All dependencies go to the business layer
Abstraction
Business is the core of the app
Communication
Communication
I
Communication
O
Communication
I
O
Communication
I
O
Communication
I
O
Communication
I
O
Communication
I
O
Communication
I
O
Communication
I
Dependency always pointing inwards
O
Communication
I
Communication can go both inwards and outwards
O
Adjusted for Android
Adjusted for Android
Entities
Entities● AKA Domain Objects, Business Objects
● No interaction with the gritty details, no database, no Internet
● Simple business logic constrained to itself or its children
● Immutable
● No persistence methods (stay tuned)
EntitiesExample: News app
● Category
● Article
● Commercial
EntitiesExample: News app with user subscriptions
● Category
● Article
● Commercial
● User
● Subscription
Use Cases
Use Cases● AKA Interactors, Business Services
● Small piece of business logic acting on one or more entities
● Must be able to describe its job by using common language (no details)
● Don’t skip use cases
Use CasesExample: Transfer money to account use case
● Load two accounts
● Do some validation
● If OK transfer money
● Save the changes
Note the simple common language
Repositories
Repositories● Perform CRUD operations on entities
● Additionally: filtering, aggregate operations, etc…
● Repository is abstract (output port)
● Concrete implementation in outer layers (DAO, API, Cache, Combination)
● Can handle entity’s whole object tree
Presenters
Presenters● Always have accompanied view
● Gather info and send them to view
● Don’t know concrete view implementation (view as output port)
● But tied to its lifecycle
● User input delegated to presenters
● Usually map entities to viewmodels
PresentersExample: Screen showing details of an account - abstraction
View
● onTransactionButtonClicked
● onUserItemSelected
● setUserListPanelVisible
● setGenderBoxEnabled
Presenter
● doTransaction
● selectUser
● showUsers
● activateGenderView
Device
Device● Gritty Android stuff
● NOT Db, Internet or UI - separate component
● Sensors, alarms, notifications, players, etc…
● Define wrappers around Android objects in Device component
● Define interface that wrapper will be implementing in domain component
to serve as an output port
Device
LocationManager
NotificationManager
AlarmManager
MediaPlayer
LocationManagerWrapper
NotificationManagerWrapper
AlarmManagerWrapper
MediaPlayerWrapper
Locations
Notifications
Alarms
Player
Use case 1
Use case 2
Use case 3
Use case 4
Device Domain
DB & API
DB & API● Also access to the real world
● This time real world are a database and the Internet
● Classes such as SQLiteOpenHelper, DbModels, DAOs, Retrofit interfaces
and services, API models, JSON parsers…
● If you are using database only, DAO can implement a repository
● Inner layers use entities, so you should also return entities -> mappers
UI
UI● Android classes used for interacting with user via display
● Fragments, Activities, Adapters, Views, Animations, etc…
● Display logic only
Modules
Modules
Domain
Modules
Device
Modules
Data
Modules
UI (app)
Modules
MVP still here
Is it better?
Is it better?
Manager this
Manager that
SRP - meh ok
Stakeholders
Mixed with
Android!Testable-ish
Is it better?
Manager this
Manager that
Is it better?
Is it better?
Is it better?Use case 1
Use case 2
Use case 3
...
Is it better?Use case 1
Use case 2
Use case 3
...
Repository
Is it better?Use case 1
Use case 2
Use case 3
...
Repository
Location
Notifications
...
Is it better?Use case 1
Use case 2
Use case 3
...
Repository
Location
Notifications
...
UI
Is it better?Use case 1
Use case 2
Use case 3
...
Repository
Location
Notifications
...
UI
Domain
Is it better?Use case 1
Use case 2
Use case 3
...
Repository
Location
Notifications
...
UI
DataDomain
Is it better?Use case 1
Use case 2
Use case 3
...
Repository
Location
Notifications
...
UI
Device
DataDomain
Is it better?Use case 1
Use case 2
Use case 3
...
Repository
Location
Notifications
...
UI
Device
Outer worldDataDomain
Is it better?Use case 1
Use case 2
Use case 3
...
Repository
Location
Notifications
...
UI
Device
Outer worldDataDomain
SRP
Is it better?Use case 1
Use case 2
Use case 3
...
Repository
Location
Notifications
...
SRP
Is it better?Use case 1
Use case 2
Use case 3
...
Repository
Location
Notifications
...
SRP
Is it better?Use case 1
Use case 2
Use case 3
...
Repository
Location
Notifications
...
SRP
Not mixed with
Android!
Is it better?Use case 1
Use case 2
Use case 3
...
Repository
Location
Notifications
...
SRP
Not mixed with
Android!
Is it better?Use case 1
Use case 2
Use case 3
...
Repository
Location
Notifications
...
SRP
Not mixed with
Android!
Is it better?Use case 1
Use case 2
Use case 3
...
Repository
Location
Notifications
...
SRP
Testable
Not mixed with
Android!
Is it better?Use case 1
Use case 2
Use case 3
...
Repository
Location
Notifications
...
SRP
Testable
Not mixed with
Android!
Is it better?Use case 1
Use case 2
Use case 3
...
Repository
Location
Notifications
...
SRP
Testable
Not mixed with
Android!UI designer cares about this
Is it better?Use case 1
Use case 2
Use case 3
...
Repository
Location
Notifications
...
SRP
Testable
Not mixed with
Android!UI designer cares about this
UX designer cares about this
Is it better?Use case 1
Use case 2
Use case 3
...
Repository
Location
Notifications
...
SRP
Testable
Not mixed with
Android!UI designer cares about this
UX designer cares about this
BA, QA, PM care about this
Is it better?Use case 1
Use case 2
Use case 3
...
Repository
Location
Notifications
...
SRP
Testable
Not mixed with
Android!UI designer cares about this
UX designer cares about this
BA, QA, PM care about this
Nobody cares about this
Is it better?Use case 1
Use case 2
Use case 3
...
Repository
Location
Notifications
...
SRP
Testable
Not mixed with
Android!UI designer cares about this
UX designer cares about this
BA, QA, PM care about this
Backend guys care about this
Nobody cares about this
Is it better?Use case 1
Use case 2
Use case 3
...
Repository
Location
Notifications
...
SRP
Testable
Not mixed with
Android!Stakeholders
are satisfied
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