clean architecture: android
TRANSCRIPT
Clean architecture: Android
Michał Szczepanik
WroDroid
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I have a Dream...
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What a Terrible Failure!
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What is Architecture?
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Architecture is About Intent, not Frameworks„
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Our goal(s)
● Architecture focused on use cases and main system function
● Clear use cases first!● Easy to maintain● Fast to test● Easy to test● Very cohesive● Decoupled
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Step 0 (setup?)
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Architect role
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Team Role
14Android best practices ?
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Entities
The business objects of the application
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Use Cases
Use Cases orchestrate the flow of data to and from the entities.
They are also called Interactors.
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Interface Adapters
This set of adapters convert data from the format most convenient for the use cases and entities.
Presenters and Controllers belong here.
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Frameworks and Drivers
This is where all the details go: UI, tools, frameworks, etc.
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How to be clean ?
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App architecture – android view
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App architecture – developer view
Presentation Layer
Domain/BusinessLayer
DataLayer
Entities Layer
Inte
ract
ors
Boun
d aries
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Domain (Business) Layer
● Application business rules● All use cases (interactors)
● Android independent
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Domain (Business) Layer
Domain/BusinessLayer
Entities LayerInte
ract
ors
Inte
rfa
ces
Repos itory (D
ata access) In terfa ce
● Interactors Implementation● Use entities objects
● Most tests are here● (JUnit plus mockito)
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Entities Layer
● Basic (minimal) business object● Object's structure● Low-level rules ● General truths
● Android independent● Framework independent
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Entities Layer
● Basic java object● No frameworks
● Test for business objects● No mocks and stubs
Domain/BusinessLayer
Entities Layer
Inte
ract
ors
Bound
aries
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Presentation Layer
● Logic related to UI (view and animation)● Logic related to Activity and application lifecycle● Fragments and Activities are only views!● Design: MVP/MVC/MVVM pattern
● Strongly connected with Android SDK
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Presentation Layer
● Frameworks
● Integration (platform) tests● UI tests● (Android Instrumentation)● (Robotium/Espresso)● (Robolectric)
Presentation Layer
Inte
ract
ors
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Data Layer
● Deliver data needed by app● Cache● Service● Design: with Repository Pattern
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Data Layer● Repository Pattern
● Integration tests● Unit tests● (JUnit plus mockito)● (Robolectric)
Implementation
Repos ito
ry Interf ace
Memory(cache)
Disk(DB/File)
Cloud
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Testing
● Low-level tests are fast ● High-level tests are slow
● UI testing sucks ?● Self testing code ?
● new bug = new test
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QA Team
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Monkey
adb shell monkey [options] <event-count>
-s <seed>
-v <verbosity level>
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Android Tips
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65K
Unable to execute dex: method ID not in [0, 0xffff]: 65536
Conversion to Dalvik format failed: Unable to execute dex: method ID not in [0, 0xffff]: 65536
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How to solve it
● Find reason– dex-method-counts
● jarjar● Shrinking libs via Proguard● Multidex
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Dalvik / ART
● Dalvik:– Register-based machine
– Just in time (JIT): 2.3+
● ART– Ahead-of-time (AOT)
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Tools?
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Lint
● Static Code Analysis● Layouts tips and optimization
● Missing translations ● Layout performance problems ● Unused resources● Inconsistent array sizes ● Accessibility and internationalization problems ● Icon problems ● Usability problems ● Manifest errors
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Dependency Injections
● Dagger
● RoboGuice
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Injections● ButterKnife
● AndroidAnnotations
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Injectionsclass ExampleActivity extends Activity {
@InjectView(R.id.title) TextView title;
@InjectView(R.id.subtitle) TextView subtitle;
@InjectView(R.id.footer) TextView footer;
@Override public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.simple_activity);
ButterKnife.inject(this);
// TODO Use "injected" views...
}
}
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Proguard / Dexguard
● Shrinking● Optimize ● Obfuscate
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Developer options
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Clean Architecture
● Easy to maintain● Easy to test● Very cohesive● Decoupled
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WroDroidhttp://www.meetup.com/WroDroid/
Clean Architecture by Unkle Bobhttp://goo.gl/Z4zMHG
Architecting Android…The clean wayhttp://goo.gl/MF13E1
Effective Android UIhttp://goo.gl/1dZxfb
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Thank you for your attention
