mayuroks

Rails ActiveRecord (association) - Cheatsheet

http://guides.rubyonrails.org/association_basics.html

Types of associations

• belongs_to : TABLE_NAME
• has_one : TABLE_NAME [:through => :TABLE_NAME]
• has_many : TABLE_NAME [:through => :TABLE_NAME]
• has_and_belongs_to_many : TABLE_NAME [:join_table => :TABLE_NAME]

mayuroks

def main():
    StNumber, StMark = input('Enter student number and student mark separated by a comma')
    StNumber = StNumber.upper()
    if len(StNumber)==9 and StNumber[0:6].isalpha() and StNumber[6:].isdigit():
        with open("output.txt", "w") as f:
            f.write(StNumber + "," + StMark + "\n")
    else:
        print("Invalid student number")

mayuroks

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="daichan4649.lockoverlay"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-sdk
        android:minSdkVersion="15"
        android:targetSdkVersion="17" />

mayuroks

/**
 * Service layer that connects/disconnects to the server and
 * sends and receives events too.
 */
public interface EventService {

    void connect(String username) throws URISyntaxException;

    void disconnect();

mayuroks

/**
 * Implementation of {@link EventService} which connects and disconnects to the server.
 * It also sends and receives events from the server.
 */
public class EventServiceImpl implements EventService {

    private static final String TAG = EventServiceImpl.class.getSimpleName();
    private static final String SOCKET_URL = "https://socket-io-chat.now.sh";
    private static final String EVENT_CONNECT = Socket.EVENT_CONNECT;
    private static final String EVENT_DISCONNECT = Socket.EVENT_DISCONNECT;

mayuroks

/**
 * Main interface to listen to server events.
 *
 */
public interface EventListener {

    void onConnect(Object... args);

    void onDisconnect(Object... args);

mayuroks

/**
 * Main interface for accessing data. It extends EventListener to receive
 * incoming events from a remote data source. In this case, a chat server.
 */
public interface DataSource extends EventListener {

    void connect(String username) throws URISyntaxException;

    void disconnect();

mayuroks

/**
 * Remote data source.
 *
 */
public class RemoteDataSource implements DataSource {

    private static RemoteDataSource INSTANCE;
    private static EventService mEventService = EventServiceImpl.getInstance();
    private EventListener mRepoEventListener;

mayuroks

/**
 * Repository can send events to a remote data source and can listen
 * for incoming events from remote data source as well. This bidirectional
 * flow of events is what makes the app realtime.
 *
 * Repository implements {@link DataSource} which can send and receive events.
 */
public class Repository implements DataSource {

    private static Repository INSTANCE = null;

mayuroks

/**
 * Listens to user actions and sends data to remote data source.
 * <p>
 * Presenter implements EventListener. Whenever the server sends events
 * to the Repository, it passes those events to the Presenter via EventListener.
 */
public class ChatPresenter implements ChatContract.Presenter {

    @NonNull
    private final BaseSchedulerProvider mSchedulerProvider;