RationApp

RationApp is a mobile application designed to help Eritrean dairy farmers calculate optimal feed rations for their livestock. Built with Flutter, the app provides a simple, offline-first interface that enables farmers to make informed feeding decisions based on scientific calculations.

Purpose

Dairy farming in Eritrea faces challenges with high feed costs and low milk production. RationApp addresses this by:

• Providing a mobile tool for calculating balanced cow feed based on specific animal characteristics
• Working completely offline, essential in areas with limited internet access
• Helping farmers optimize feed costs while maintaining proper nutrition
• Supporting agricultural extension officers during farm visits

Features

Cow Characteristics Input

• Input cow details (weight, pregnancy status, milk production, etc.)
• User-friendly dropdown menus and text fields

Nutritional Requirements Calculator

• Calculates precise nutritional needs based on cow characteristics
• Shows requirements for dry matter, energy, protein, and minerals

Feed Formula Planner

• Add and edit fodder and concentrate ingredients
• Track nutritional values of feed mixes
• Visual indicators show when nutrient levels meet requirements

Price Tracking

• Update local feed prices
• Calculate the cost of different feed combinations

Feed Optimizer

• Suggests the most cost-effective feed mix that meets nutritional requirements

Multilingual Support

• Available in multiple languages (English, Arabic, Tigrinya)

Offline Functionality

• All features work without internet connection
• Data is stored locally on the device

Handover Guide for NGO Staff

This section provides essential guidance for non-technical users who need to maintain and update the app after the initial development phase.

Modifying App Content

Updating Text and Translations

1. Locate the language files: All text content is stored in the lib/l10n directory in .arb files:

   • intl_en.arb - English text
   • intl_ar.arb - Arabic text
   • intl_ti.arb - Tigrinya text

2. Edit the files: Open these files with any text editor (like Notepad, TextEdit, or Visual Studio Code). The format looks like this:

   "concentrateSorghumGrain": "Sorghum grain",
   "@concentrateSorghumGrain": {
       "description": "Concentrate: Sorghum grain"
   },

3. Make your changes:

   • Edit only the text inside the quotation marks after the key (e.g., "Sorghum grain")
   • Do not change the keys (the text before the colon, e.g., "concentrateSorghumGrain")
   • The description field helps translators understand the context
   • Make sure to maintain the JSON format with proper commas and brackets

4. Save the files: Save the changes and proceed to building an update.

Updating Feed Ingredient Information

To modify nutritional values or add new feed ingredients:

1. Open lib/data/nutrition_tables.dart
2. For existing ingredients, find the relevant item in either fodderItems or concentrateItems list
3. Update the nutritional values as needed
4. To add a new ingredient:
   • Add a new FeedIngredient entry following the existing pattern
   • Include the ID, name, and all nutritional parameters
   • Add corresponding translation keys to the .arb files

Building and Distributing Updates

Once you've made your content changes, you'll need to build and distribute the updated app:

Prerequisites

1. Install Flutter: Follow the Flutter installation guide
2. Install Visual Studio Code: Download from code.visualstudio.com
3. Install Git: Download from git-scm.com

Building the App

1. Get the code:

   git clone https://github.com/minerva-university/rationapp.git
   cd rationapp
   

2. Install dependencies:

   flutter clean
   flutter pub get
   

3. Build the APK (for Android):

   flutter build apk
   

   The APK will be located at build/app/outputs/flutter-apk/app-release.apk

Distributing the Update

For regions with limited connectivity, use these methods to distribute updates:

1. Direct APK sharing: Provide the APK file to extension officers via:

   • USB drives (most common method)
   • Email (where internet is available)
   • Bluetooth transfer

2. Installation instructions for extension officers:

   • Copy the APK file to the farmer's phone
   • Navigate to the file using a file manager
   • Tap the APK file to install (may need to enable "Install from Unknown Sources" in settings)
   • If updating an existing installation, the app data will be preserved

Creating User Guides

When distributing updates, consider providing:

1. Change summary: A simple document explaining what has changed in the new version
2. Visual guides: Screenshots showing new features or modified screens
3. Training sessions: Brief in-person demonstrations for extension officers

Setup Instructions for Developers

Prerequisites

• Flutter SDK
• Android Studio or VS Code with Flutter extensions
• An Android or iOS device/emulator

Installation

1. Clone the repository:

   git clone https://github.com/minerva-university/rationapp.git
   

2. Navigate to the project directory:

   cd rationapp
   

3. Get dependencies:

   flutter clean
   flutter pub get
   

4. Run the app:

   flutter run
   

Project Structure

• constants/ - Static data and configuration
• data/ - Nutrition tables and local data sources
• l10n/ - Language localization files
• models/ - Data structures for core app concepts
• screens/ - Main UI pages
• services/ - Business logic and data management
• utils/ - Calculation utilities including feed optimization
• widgets/ - Reusable UI components

Key Components

Core Calculation Modules

• cow_requirements_calculator.dart - Calculates nutritional needs
• feed_calculator.dart - Processes feed mixture calculations
• feed_optimizer.dart - Implements linear optimization for least-cost feed

Data Management

• persistence_manager.dart - Handles local data storage using SharedPreferences
• feed_state.dart - Manages application state for feed ingredients

User Interface

• home_screen.dart - Main navigation interface
• cow_characteristics_page.dart - Input screen for cow details
• feed_formula_page.dart - Feed planning interface

Testing

The project includes comprehensive unit tests covering core functionality. Run tests with:

flutter test

Acknowledgments

• Developed as part of the CSARIDE (Climate Smart Agriculture Research and Innovation Support for Dairy Value Chains in Eritrea) project
• Based on validated feeding calculations provided by dairy nutrition experts

Quick Demo

https://drive.google.com/file/d/1SWrLI1id3nmioVazO3mt5RVLcD0GxiHE/view?usp=sharing

With Localization

https://drive.google.com/file/d/1gP4m_uVphBi3CbbMOgZzetGX9MLo5bkG/view?usp=sharing

---

For questions or support, please contact somtochiumeh@gmail.com