Understand Properties in Codename One

How do I?

public class Meeting { private Date when; private String subject; private int attendance; public Date getWhen() { return when; } public String getSubject() { return subject; } public int getAttendance() { return attendance; } public void setWhen(Date when) { this.when = when; } public void setSubject(String subject) { this.subject = subject; } public void setAttendance(int attendance) { this.attendance = attendance; } }

Classic Properties

Understanding Properties

public class Meeting { private Date when; private String subject; private int attendance; public Date getWhen() { return when; } public String getSubject() { return subject; } public int getAttendance() { return attendance; } public void setWhen(Date when) { this.when = when; } public void setSubject(String subject) { this.subject = subject; } public void setAttendance(int attendance) { this.attendance = attendance; } }

Classic Properties

public class Meeting implements PropertyBusinessObject { public final Property<Date,Meeting> when = new Property<>("when", Date.class); public final Property<String,Meeting> subject = new Property<>("subject"); public final IntProperty<Meeting> attendance = new IntProperty<>("attendance"); private final PropertyIndex idx = new PropertyIndex(this, "Meeting", when, subject, attendance);

@Override public PropertyIndex getPropertyIndex() { return idx; } }

New Properties

Meeting meet = new Meeting(); meet.setSubject("My Subject"); Log.p(meet.getSubject());

Usage

Meeting meet = new Meeting(); meet.subject.set("My Subject"); Log.p(meet.subject.get());

Builder Construction

Meeting meet = new Meeting(). subject.set("My Subject"). when.set(new Date());

Encapsulation & Observability

public final Property<String,Meeting> subject = new Property<>("subject", "") { public Meeting set(String value) { if(value == null) { return Meeting.this; } return super.set(value); } };

meet.subject.addChangeListener((p) -> Log.p("New property value is: " + p.get()));

Object Methods…@Override public String toString() { return idx.toString(); }

@Override public boolean equals(Object obj) { return obj.getClass() == getClass() && idx.equals(((Meeting)obj).getPropertyIndex()); }

@Override public int hashCode() { return idx.hashCode(); }

JSON Parsing/Generating

// read JSON String meet.getPropertyIndex().loadJSON(jsonString);

// Convert Object to JSON String String jsonString = meet.toJSON();

Seamless Serialization

// register once in the init(Object) method new Meeting().getPropertyIndex().registerExternalizable();

// writes the object using implicit externalizable interface writeObjectToStorage("MyMeeting", meeting);

// Loads an object instance from a storage entry Meeting readContact = (Meeting)readObjectFromStorage("MyMeeting");

ORM - Database/SQL MappingMeeting m = new Meeting(); Database db = Display.getInstance().openOrCreate("Meeting.db"); SQLMap sm = SQLMap.create(db);

// we'll need to add a Long property id field to get auto increment sm.setPrimaryKeyAutoIncrement(m, m.id); sm.createTable(m);

// we can then do standard CRUD operations: sm.insert(myMeeting); sm.update(myMeeting); sm.delete(myMeeting);

List<PropertyBusinessObject> meetings = sm.select(new Meeting(), null, true, 1000, 0); for(PropertyBusinessObject cc : contacts) { Meeting currentMeeting = (Meeting)cc; // ... }

UI Binding & Auto Generation

UiBinding uib = new UiBinding();

// changes to subject will update the field and visa versa uib.bind(subjectTextField, myMeeting.subject);

// Creates a container that allows us to edit the // meeting content Form current = new Form("Meeting", BoxLayout.y()); InstantUI iui = new InstantUI(); current.add(iui.createEditUI(new Meeting(), true)); current.show();

UI Binding & Auto Generation

UiBinding uib = new UiBinding();

// changes to subject will update the field and visa versa uib.bind(subjectTextField, myMeeting.subject);

// Creates a container that allows us to edit the // meeting content Form current = new Form("Meeting", BoxLayout.y()); InstantUI iui = new InstantUI(); current.add(iui.createEditUI(new Meeting(), true)); current.show();

UI Binding & Auto Generation

UiBinding uib = new UiBinding();

// changes to subject will update the field and visa versa uib.bind(subjectTextField, myMeeting.subject);

// Creates a container that allows us to edit the // meeting content Form current = new Form("Meeting", BoxLayout.y()); InstantUI iui = new InstantUI(); current.add(iui.createEditUI(new Meeting(), true)); current.show();

Thank You!