learning-machine-android

Blockcerts Android application by Learning Machine

Build variants

Gradle allows us to define different product variants. Each has a separate app id and can be installed simultaneously. Currently they all use the Bitcoin main net and do not differ all that much. Production has an empty logging tree.

dev
- App id: com.learningmachine.android.app.dev
- Dimension: env
staging
- App id: com.learningmachine.android.app.staging
- Dimension: env
production
- App id: com.learningmachine.android.app
- Dimension: env

Running Tests

sh scripts/run_tests.sh

At the time of writing it seems Robolectric is not compatible with JDK > 13 (robolectric/robolectric#5863)

Building APKs

sh scripts/GenerateReleaseBuild.command Answer the prompts as they come. Blockcerts team members: password is stored in regular password manager.

Glossary

Conventions

The following are guidelines for this Android project.

Classes

Naming
- Suffix with the type of class: Activity, Fragment, Listener, ListItemView, Manager
- Prefix member variables with m.
- If a variable is a view, consider suffixing with the type: mPasswordEditText, mLoginButton
- Boolean member variables should reflect state (mLocked) and have getters using isState() (ie: isLocked)
Extract common elements to a superclass to avoid duplication.
Prefer abstract methods in super over implicit setup in subclass constructors.
The suggested template below should guide naming:

public class TemplateFragment {

    private static final String ARG_CONSTANT = "TemplateFragment.Constant";

    private List<Object> mObjects;

    /* static methods */

    public static TemplateFragment newInstance() {
        return new TemplateFragment();
    }

    /* lifecycle overrides, onSavedInstanceState, options menu, onActivityResult */

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        mObjects = new ArrayList<Object>();
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup parent, Bundle savedInstanceState) {
        // databinding & init
        initView();
    }

    /* private methods */

    private void initView() {}

    private void setupData() {}

    /* getters, setters, and other public methods */

    public List<Object> getObjects() {
        return mObjects;
    }

    public void setObjects(List<Objects> objects) {
        mObjects = objects;
    }

    /* enums */

    protected enum ObjectItemType {
        ITEM_TYPE_A,
        ITEM_TYPE_B,
    }

    /* inner classes */

    private class TemplateListAdapter extends ArrayAdapter<ObjectItemType> {

        public EnergyListAdapter(List<ObjectItemType> items) {
            super(getActivity(), 0, items);
        }
    }

    /* base class overrides */

    @Override
    protected boolean usesInjection() {
        return true;
    }
}

We suggest the following method orgainization:

newInstance and other static methods

lifecycle, onSavedInstanceState, options menu, onActivityResult
private methods
all other protected methods (including immediate parent overrides)
all other public methods(including immediate parent overrides)
enums
defined interfaces
inner classes
base overrides

Layout files

Naming
- Reverse DNS style.
- Prefix with the type of layout: activity_login, fragment_login, list_item_login
- Describe widgets and suffix with the type: login_username_text_view
Use auto format for consistency.
Prefer /> over open and close tags that do not contain children.
Extract strings and dimensions to their respective xml resources. 0dp is an exception and should remain in the layout file.
Use styles when possible.
id's should come first for easy element identification, and be on a new line. Enable Preferences > Code Style > XML > Android > Insert Line break before first attribute to help format your layout files properly.

`strings.xml`

Naming
- Describe where it is used: fragment_login_username_hint
- For long strings, append _message: "We would like to welcome you to this app because it is amazing" becomes fragment_login_welcome_message
- If error, append _error_message: "Failed to login" would be login_error_message
Formatted strings
- Use the recommended pattern: %1$s
- Use the correct type for the data it will be formatting: s, d, f, etc.

Managers

Responsibilities
- Loading and providing data
- Creating success and failure callbacks
- Fetching / pushing data from / to the WebService
Prefix data operations with load, this signifies an asynchronous call (i.e. webservice or database)
Prefix direct data accessors with get. These methods will synchronously return data directly to the caller.

Stores

Controllers (i.e. Activities and Fragments) should never access Stores directly. All requests to load or get data should be relayed through a Manager.

Interfaces / Callbacks

We like and make extensive use of these.
They are a great way to enforce implementation of something a calling class may need.

Blockcerts Libraries

Cert-verifier-js

Javascript library for verifying Blockcerts Certificates

Updating cert-verifier-js to a new version

Pull down the cvjs repository:

https://github.com/blockchain-certificates/cert-verifier-js.git && cd cert-verifier-js

CVJS requires an npm token, so create one on npm

export NPM_TOKEN={insert token here}

Install

npm install

Generate build

npm run-script build

Copy content of /dist/verifier-iife.js

Paste in this android project at this location: wallet-android/LearningMachine/app/src/main/assets/www/verifier.js

External Libraries

Autolinker.js

Utility to convert urls found in HTML into links
Minified javascript included as a static asset in the www directory of the app
MIT

BitcoinJ

Java implementation of the Bitcoin protocol
Forked by uniquid to allow creation of wallets with arbitrary path (e.g m/44'/0'/0/0)
Apache License

SLF4J

Simple Logging Facade for Java
Required by BitcoinJ
MIT

Spongy Castle

Repackage of Bouncy Castle for Android
Required by BitcoinJ
MIT X11

Protobuf

Google's language-neutral, platform-neutral, extensible mechanism for serializing structured data
Required by BitcoinJ
License

Dagger 2

Dependency injection framework
Apache 2.0

Timber

A logger with a small, extensible API which provides utility on top of Android's normal Log class
Apache 2.0

JodaTime Android

A version of Joda-Time built with Android in mind
Apache 2.0

Retrofit

A type-safe REST client for Android and Java
Apache 2.0

Okhttp

An HTTP+HTTP/2 client for Android and Java applications
Apache 2.0

Gson

JSON object converter and parser
Apache 2.0

RxJava

RxJava bindings for Android
Apache 2.0

RxLifecycle

Automatically complete sequences based on a second lifecycle stream
Apache 2.0

RxLint

A set of lint checks that check your RxJava code
Apache 2.0

Picasso

Image loading and caching
Apache 2.0

Guava

Google Core Libraries for Java
Apache 2.0

JUnit

A simple framework to write repeatable tests.
Eclipse Public License - v 1.0

Mockito

Tasty mocking framework for unit tests in Java
MIT

Robolectric

Unit testing framework
MIT

JodaTime

A quality replacement for the Java date and time classes
Required for unit tests
Apache 2.0

ajsarun / wallet-android