reactive_orm 0.0.7

A reactive object-relationship state management layer for Flutter with fine-grained field reactivity.

reactive_orm

|

⚠️ Note: reactive_orm stands for a Reactive Object–Relationship Model.
It is not a database ORM.
It is a lightweight, field-level state management solution for Flutter UI, inspired by ORM-style modeling of objects and relationships — fully in-memory and UI-focused.

---

🎬 Demo

---

✨ Core Philosophy

• Models are plain Dart objects
• State changes happen via normal field mutation
• UI reacts automatically, with optional field-specific reactivity
• No ChangeNotifier, providers, streams, or extra boilerplate
• Supports object-wise, field-wise, and nested reactivity
• ORM-inspired design:
  • Objects represent application state
  • Relationships define propagation (Many → One, Many ↔ Many)
  • Reactivity keeps the UI in sync

---

✨ Features

• ✅ Reactive models with automatic UI updates
• ✅ Object-wise reactivity (entire model rebuilds)
• ✅ Field-wise reactivity (only selected fields rebuild)
• ✅ Nested & shared models supported
• ✅ Many → One and Many ↔ Many relationships
• ✅ Multiple widgets can listen to the same model
• ✅ Minimal boilerplate
• ✅ ORM-style mental model (Objects + Relationships)

---

🆚 Comparison

Feature	ValueNotifier	reactive_orm
Observes a single field?	Yes (one notifier per field)	Yes (field-wise) + whole object
Field assignment syntax	notifier.value = newValue	model.field = newValue (auto-notifies)
Multiple widgets listening	Manual wiring	Automatic
Nested models	Manual	Built-in (addNested)
Relationships	❌	✅ Many → One, Many ↔ Many
Boilerplate	Medium → High	Minimal, ORM-style
Ideal for	Simple values	Complex reactive domain models

---

🚀 Getting Started

Installation

dependencies:
  reactive_orm: ^0.0.7

---

🧩 Basic Usage

1️⃣ Create a Reactive Model

import 'package:reactive_orm/reactive_orm.dart';

class Task extends ReactiveModel {
  String _title;
  bool _completed = false;
  String _status = "Idle";

  Task({required String title}) : _title = title;

  String get title => _title;
  set title(String value) {
    if (_title != value) {
      _title = value;
      notifyListeners('title');
    }
  }

  bool get completed => _completed;
  set completed(bool value) {
    if (_completed != value) {
      _completed = value;
      notifyListeners('completed');
    }
  }

  String get status => _status;
  set status(String value) {
    if (_status != value) {
      _status = value;
      notifyListeners('status');
    }
  }
}

---

2️⃣ Object-wise Reactivity (Whole Object)

Any field change rebuilds the widget:

final task = Task(title: "Object-wise");

ReactiveBuilder<Task>(
  model: task,
  builder: (t) => ListTile(
    title: Text(t.title),
    subtitle: Text(t.status),
    trailing: Checkbox(
      value: t.completed,
      onChanged: (v) => t.completed = v!,
    ),
  ),
);

---

3️⃣ Field-wise Reactivity (Optimized)

Widget rebuilds only when specified fields change:

final task = Task(title: "Field-wise");

ReactiveBuilder<Task>(
  model: task,
  fields: ['completed', 'status'],
  builder: (t) => ListTile(
    title: Text(t.title),
    subtitle: Text(t.status),
    trailing: Checkbox(
      value: t.completed,
      onChanged: (v) => t.completed = v!,
    ),
  ),
);

• Rebuilds only when completed or status changes.
• Changes to other fields are ignored.

---

🔗 Relationship Patterns

1-> Many → One (Aggregation)

Multiple models feed a single reactive observer:

class Dashboard extends ReactiveModel {
  final List<Task> sources;
  Dashboard(this.sources) {
    for (final task in sources) addNested(task);
  }
}

final dashboard = Dashboard([task1, task2]);

ReactiveBuilder<Dashboard>(
  model: dashboard,
  builder: (_) => Text("Dashboard updated"),
);

• ✔ Any task change updates the dashboard automatically.

2-> Many ↔ Many (Shared Models)

Same model instance used across multiple parents:

class Group extends ReactiveModel {
  final String name;
  final List<Task> tasks;

  Group({required this.name, required this.tasks}) {
    for (final task in tasks) addNested(task);
  }
}

• ✔ One task update reflects everywhere.
• ✔ No duplication or manual syncing required.

---

🧠 How It Works (High Level)

• Models extend ReactiveModel.
• Field setters call notifyListeners(fieldName) when the value changes.
• ReactiveBuilder widgets listen to either:
  • Whole model (object-wise)
  • Specific fields (field-wise)
• Nested models propagate changes upward automatically.
• Widgets rebuild safely, respecting Flutter lifecycle.

---

🛣 Roadmap

• Batch updates / transactions
• Async persistence hooks
• Database adapters (optional)
• DevTools / debug inspector
• Optional code generation

---

🧪 Status

• Version: 0.0.7
• Stability: Stable / suitable for prototyping and early production
• Use case: Learning, prototyping, early production experiments

---

📌 Summary

reactive_orm is ideal when you want:

• Clean Dart models with fine-grained reactivity
• A Reactive Object–Relationship Model for UI state
• Object-wise and field-wise rebuild control
• Nested and shared models without manual wiring
• Minimal boilerplate with a clear mental model
• A lightweight yet scalable state management solution for Flutter apps