Propoid is a small library to support properties in Java:

• small footprint
• very simple to use: distributed as aar, no code generation, no effect on tool chain, no setup required
• reflection runtime overhead only during application startup (i.e. when classes are loaded)
• very small memory overhead for each propoid
• see propoid-core for caveats

Simple but powerful solution to persist your propoids in Sqlite:

Repository repository = new Repository(context, "foos");

No creation of table schema needed, just insert your objects

Foo foo = new Foo();
repository.insert(foo);

Typed queries

Foo foo = new Foo();
repository.query(foo, Where.equal(foo.bar, "my bar")).first();

Efficiently iterate over matched propoids (backed by a cursor)

Foo foo = new Foo();
for (Foo match : repository.query(foo, Where.equal(foo.bar, "my bar")).list(Order.ascending(foo.baz)) {
    match.baz();
};

Perform mass updates

Foo foo = new Foo();
repository.query(foo).set(foo.bar, "my bar");

• Use inheritance (single-table mapping)
• Relations are lazily loaded (many-to-one and one-to-many)
• Table schema is altered for new properties automagically.

Pass propoids between activities and fragments via references:

Reference<Foo> in = new Reference<>(foo);

Intent intent = new Intent(context, FooActivity.class);
intent.setData(in.toUri());

...

Reference<Foo> out = Reference.from(intent);
Foo foo = repository.get(out);

Add validation to your objects:

Foo foo = new Foo();
new MinLengthValidator(foo.bar, R.string.bar_min_length, 4);

Bind properties to views:

Foo foo = new Foo();
new TextBinding(foo.bar, editText);

• all changes are automatically synced between property and a view, bidirectional!
• use one of default converters or add your own
• handles conversion and validation errors automatically

Bind ListView to matched Propoids:

MatchAdapter adapter = new MatchAdapter<Foo>(repository.query(new Foo())) {
    protected void bind(int position, View view, Foo foo) {
        Index index = Index.get(view);
        
        TextView textView = index.get(R.id.foo_bar);
        textView.setText(foo.bar.get());
    }
};
listView.setAdapter(adapter);
adapter.initLoader(0, this);

• no UI freeze: database is queried asynchronously and the listView updated with the results
• Propoids are instantiated for visible views only (backed by cursor)
• list is automatically updated whenever Propoids are changed in the database
• fast and convenient access to views via propoid.ui.Index

To benefit from these features your objects have to adhere to the following restrictions:

public class Foo extends Propoid {
  public final Property<String> bar = property();

  public Foo() {
  }
}

• extend propoid.core.Propoid
• add a default constructor
• declare all fields as public final propoid.core.Property

android, java, properties, persistence, db, database, sqlite, sql, orm, or-mapper, hibernate, active-record, binding