Effective Android Development

A presentation of the techniques, tools & process that we employ during our daily work to build high-quality apps for our clients. Not a code-heavy, deep-down into our architecture kinda talk, but a high-level behind the scenes about our process to move from prototyping to design and to production. We want to stay nimble during development, and quickly iterate over features, which we like to accomplish through frequent releases, often paired with A/B testing. At the same time, we are convinced that building robust applications is helped with a Continuous Delivery setup where we highly value an automated test strategy. Working in an agile way while focusing on good architecture, testing and reporting took us some effort, and I’d like to explore how we run our projects trying to be as effective and collaborative as possible...
Presented during the Devoxx conference on Thursday, 10th November 2016.
http://cfp.devoxx.be/2016/talk/VOW-7651/Effective_Android_dev

Transcript

1. Effective Android
   

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2. Effective (Android) development
   

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3. AppFoundry
   appfoundry.be
   

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5. –H. Alan Stevens
   Building the right thing is always more important than
   building it right.
   

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6. Prototyping
   

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7. Whiteboard
   

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8. Paper prototyping
   

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15. Remote configuration
    

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16. Remote configuration
    - Check flags
    - maintenance
    - upgrade
    - Do specific work (load menu, …)
    - Check and act on feature switches
    Production API Test API
    Load Production config file
    https://xxxxx/2.1.json
    Load Test config file
    https://xxxxx/2.1-test.json
    

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17. –Martin Fowler
    Feature toggles are a powerful technique, allowing teams
    to modify system behavior without changing code.
    

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18. Key / value pairs @ Firebase
    Firebase
    Remote
    Config
    Change behaviour at runtime
    Developer console
    dynamic (no app update required)
    rules & conditions
    hosted, scalable, cross platform
    

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20. User feedback
    

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21. A/B testing
    

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24. Architecture
    

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25. Architecture
    

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26. MODEL
    PRESENTER
    VIEW
    View Presenter
    View
    View
    Presenter
    Presenter
    Data Manager
    Interactors
    Prefs
    API
    API
    DB
    Network
    service
    Network
    service
    Preferences
    Helper
    Observables
    Observables
    Presentation Layer Domain Layer Data Layer
    STREAM
    Architecture
    

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27. Model View Presenter
    Model
    Presenter
    View
    

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28. Model View Presenter
    Model
    Presenter
    View
    Android
    UI
    

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29. MODEL
    PRESENTER
    VIEW
    View Presenter
    View
    View
    Presenter
    Presenter
    Data Manager
    Interactors
    Prefs
    API
    API
    DB
    Network
    service
    Network
    service
    Preferences
    Helper
    Observables
    Observables
    Presentation Layer Domain Layer Data Layer
    STREAM
    Architecture
    

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30. Consistent
    Expressive
    Concise
    Verbose
    

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31. X
    

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32. Jetbrains
    Kotlin
    Good interoperability with Java
    Modern
    Small standard library (±600kb)
    Statically typed, no runtime overhead
    Reduce common errors
    Reduce boilerplate
    

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33. Data class
    public class User {

    

    private String firstName;

    private String lastName;

    private int age;

    

    public int getAge() {

    return age;

    }

    

    public void setAge(int age) {

    this.age = age;

    }

    

    public String getFirstName() {

    return firstName;

    }

    

    public void setFirstName(String firstName) {

    this.firstName = firstName;

    }

    

    public String getLastName() {

    return lastName;

    }

    

    public void setLastName(String lastName) {

    this.lastName = lastName;

    }

    

    @Override

    public boolean equals(Object o) {

    if (this == o) return true;

    if (o == null || getClass() != o.getClass()) return false;

    

    User user = (User) o;

    

    if (age != user.age) return false;

    if (firstName != null ? !firstName.equals(user.firstName) : user.firstName != null) {

    return false;

    }

    return lastName != null ? lastName.equals(user.lastName) : user.lastName == null;

    }

    

    @Override

    public int hashCode() {

    int result = firstName != null ? firstName.hashCode() : 0;

    result = 31 * result + (lastName != null ? lastName.hashCode() : 0);

    result = 31 * result + age;

    return result;

    }

    

    @Override

    public String toString() {

    return "User{" +

    "age=" + age +

    ", firstName='" + firstName + '\'' +

    ", lastName='" + lastName + '\'' +

    '}';

    }

    }
    @AutoValue

    public abstract class User {

    

    public abstract String firstName();

    

    public abstract String lastName();

    

    public abstract int age();

    

    @AutoValue.Builder

    public abstract static class Builder {

    

    public abstract Builder firstName(String s);

    

    public abstract Builder lastName(String s);

    

    public abstract Builder age(int i);

    }

    

    public static Builder builder() {

    return new AutoParcel_User.Builder();

    }

    

    public abstract Builder toBuilder();

    }
    

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34. Data class
    public class User {

    

    private String firstName;

    private String lastName;

    private int age;

    

    public int getAge() {

    return age;

    }

    

    public void setAge(int age) {

    this.age = age;

    }

    

    public String getFirstName() {

    return firstName;

    }

    

    public void setFirstName(String firstName) {

    this.firstName = firstName;

    }

    

    public String getLastName() {

    return lastName;

    }

    

    public void setLastName(String lastName) {

    this.lastName = lastName;

    }

    

    @Override

    public boolean equals(Object o) {

    if (this == o) return true;

    if (o == null || getClass() != o.getClass()) return false;

    

    User user = (User) o;

    

    if (age != user.age) return false;

    if (firstName != null ? !firstName.equals(user.firstName) : user.firstName != null) {

    return false;

    }

    return lastName != null ? lastName.equals(user.lastName) : user.lastName == null;

    }

    

    @Override

    public int hashCode() {

    int result = firstName != null ? firstName.hashCode() : 0;

    result = 31 * result + (lastName != null ? lastName.hashCode() : 0);

    result = 31 * result + age;

    return result;

    }

    

    @Override

    public String toString() {

    return "User{" +

    "age=" + age +

    ", firstName='" + firstName + '\'' +

    ", lastName='" + lastName + '\'' +

    '}';

    }

    }
    data class User(val firstName: String, val lastName: String, val age: Int)
    val user = User("Andy", "Rubin", 53)
    println(user)
    // User(firstName=Andy, lastName=Rubin, age=53)
    val usersBirthDay = user.copy(age = 54) // Named parameters

    println(usersBirthDay) // User(firstName=Andy, firstName=Rubin, age=54)
    

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36. Nullability
    var x: String? = "foo"

    

    x = null

    

    x.length // Does not compile
    

    

    val y: String = null // Does not compile
    

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37. Nullability
    if (x != null) {

    x.length // Compiles

    }

    

    // Safe call

    val length = x?.length // Value null

    

    // Default value

    val length = if (x != null) x.length else -1 // Value -1

    

    // Elvis operator

    val length = x?.length ?: -1 // Value -1
    

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38. Kotlin
    • Properties
    • Data class
    • Function literal (Lambda)
    • Higher order functions
    • Extension functions
    • …
    

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40. Layout
    android:layout_width="match_parent"

    android:layout_height="match_parent"

    android:fitsSystemWindows="true">

    

    android:layout_width="match_parent"

    android:layout_height="wrap_content">

    

    android:id="@+id/toolbar"

    android:layout_width="match_parent"

    android:layout_height="?attr/actionBarSize"/>

    

    

    

    android:id="@+id/container"

    android:layout_width="match_parent"

    android:layout_height="match_parent"

    app:layout_behavior="@string/appbar_scrolling_view_behavior"/>

    

    
    

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41. Layout Anko
    android:layout_width="match_parent"

    android:layout_height="match_parent"

    android:fitsSystemWindows="true">

    

    android:layout_width="match_parent"

    android:layout_height="wrap_content">

    

    android:id="@+id/toolbar"

    android:layout_width="match_parent"

    android:layout_height="?attr/actionBarSize"/>

    

    

    

    android:id="@+id/container"

    android:layout_width="match_parent"

    android:layout_height="match_parent"

    app:layout_behavior="@string/appbar_scrolling_view_behavior"/>

    

    
    coordinatorLayout {

    fitsSystemWindows = true

    

    appBarLayout {
    

    toolBar = toolbar {

    if (SDK_INT >= LOLLIPOP)
    elevation = 4f

    }.lparams(width = matchParent,
    height = actionBarSize())
    }.lparams(width = matchParent)

    

    changeHandlerFrameLayout()

    .lparams(width = matchParent,
    height = matchParent) {

    behavior = ScrollingBehavior()

    }
    

    }
    

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42. Layout
    

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43. Advanced Layout
    

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44. Advanced Layout
    

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45. Anko performance test
    Specs ANKO XML Diff
    ALCATEL

    ONE TOUCH
    Mediatek MT6572

    Dual-core 1.3GHz Cortex-A7

    512MB RAM
    169.33 ms 608.66 ms 359%
    HUAWEI Y300
    Qualcomm MSM8225

    Dual-core 1.0 GHz Cortex-A5
    512 MB RAM
    593.66 ms 3435.33 ms 578%
    HUAWEI Y330
    Mediatek MT6572
    Dual-core 1.3 GHz Cortex-A7
    512MB
    162.33 ms 984 ms 606%
    Samsung
    Galaxy S2
    Exynos 4210 Dual
    Dual-core 1.2 GHz Cortex-A9
    1 GB RAM
    207.33 ms 753.66 ms 363%
    

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46. Testing
    

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47. Testing strategy
    

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48. Confidence
    Refactor possible
    Code handover
    Fix bugs once
    

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49. Automatic
    On every commit / scheduled
    Unit tests
    UI integration tests
    with Espresso
    

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50. Test devices
    

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51. Device testing
    

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57. Remote
    

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60. Google Cloud Test Lab
    

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61. Google Cloud Test Lab
    

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62. Google Cloud Test Lab
    

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63. Creating software = complex
    Continuous
    integration Ensure quality
    Automate
    high-quality, robust and reliable apps
    tedious / error-prone activities
    

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64. Reduce risk
    Continuous
    integration Reduce overhead
    Quality Assurance
    

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65. Automate all the things
    

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66. Continuous integration
    1
    2
    3
    4
    CODE & COMMIT BUILD & CHECK
    CI PICKUP
    REPORT RESULTS
    

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67. Build pipeline
    Checkout /
    compile
    Unit tests
    Test
    coverage
    Code
    analysis
    Create
    deployable
    artifact
    Deploy for
    automatic
    QA test
    Trigger
    automated
    QA stage
    

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68. Static analysis
    

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69. Auto publish
    Delivery
    Promote APK to production
    Automate
    Google Play alpha / beta
    without additional tools
    

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70. Continuous
    Delivery
    

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71. Continuous delivery / deliverable
    Continuous
    Delivery
    Deliverable Push on demand
    Confidence
    of being deployable
    

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72. Feature-based deployment
    A successful Git branching model
    http://nvie.com/posts/a-successful-git-branching-model/
    

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73. Code review
    Detect problems early.
    Learn from someone else’s code.
    

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79. Test app distribution
    

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80. Hockey test app distribution
    

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81. Fabric Beta app distribution
    

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82. Fabric Beta app distribution
    

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84. Internal QA
    Testing
    Internal alpha testing program
    Beta testing / staged rollout
    of being deployable
    

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85. Metrics
    

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86. Crashlytics
    

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87. Dashboard
    

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88. Dashing
    

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89. Questions?
    Filip Maelbrancke
    Consultant @ AppFoundry
    filip.maelbrancke@appfoundry.be
    @fmaelbrancke
    

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90. Thank you!
    

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