Skip to main content

​
Overview

Trackmart’s ordering system allows buyers to request product deliveries (such as sand and other construction materials) with real-time pricing and driver selection. The order workflow integrates quantity selection, dynamic pricing, payment methods, and driver assignment.

​
Order Creation Flow

The order creation process follows these key steps:
1

Select a Driver

Users can search for available drivers by name or phone number, or browse through the list of registered merchants.
2

Configure Order Details

Set the quantity, unit type (Truck or Tonne), and payment method (Mobile money or Cash).
3

Review Pricing

Real-time pricing is fetched and displayed, showing the cost per unit and total amount.
4

Confirm and Submit

Review the order details in a confirmation dialog before submitting the delivery request.

​
Product Selection

Currently, Trackmart focuses on construction materials, primarily sand delivery.
The product type is currently set to ‘Sand’ in the codebase, but the architecture supports expansion to other products.

​
Available Units

Truck

Order by full truck load

Tonne

Order by weight (metric tonnes)

​
Quantity Management

Users can adjust order quantity through multiple methods: 
void _minus() {
  if (double.parse(_moneyController.text) >= 1) if (mounted)
    setState(() {
      _moneyController.text =
          '${(double.tryParse(_moneyController.text) ?? 0) - 1}';
      _moneyController2.text =
          '${(double.parse(_moneyController.text) * (rate ?? 0)).toStringAsFixed(0)}';
    });
}

void _plus() {
  if (mounted)
    setState(() {
      _moneyController.text =
          '${(double.tryParse(_moneyController.text) ?? 0) + 1}';
      _moneyController2.text =
          '${((double.tryParse(_moneyController.text) ?? 0) * (rate ?? 0)).toStringAsFixed(0)}';
    });
}
The minimum order quantity is 1 unit. The system automatically calculates the total price when quantity changes.

​
Dynamic Pricing

Pricing is fetched dynamically and updates in real-time: 
_moneyController.addListener(() {
  if (_moneyController.text.isEmpty) {
    if (mounted)
      setState(() {
        _moneyController2.text = "";
      });
  } else if (_focus.hasFocus) {
    {
      _moneyController2.text =
          (double.parse(_moneyController.text) * (rate ?? 0))
              .toStringAsFixed(0);
    }
  }
});
The app displays:
  • Rate per unit: 1 [Unit] of [Product] costs UGX [Price]
  • Total amount: Automatically calculated based on quantity × rate
  • Currency: UGX (Uganda Shillings)
Orders cannot be submitted if pricing information is unavailable. Ensure internet connectivity for rate fetching.

​
Payment Methods

Trackmart supports two payment methods:
The default payment method for digital transactions through mobile money services.

​
Order Data Structure

Each order contains the following information: 
Order makeOrderNow() {
  return Order(
    destlat: currentLat,
    destlong: currentLong,
    driverId: filteredDrivers[_selected].id,
    driverName: filteredDrivers[_selected].name,
    driverPhone: filteredDrivers[_selected].phone,
    userId: currentUserId,
    userName: currentUserName,
    userPhone: currentUserPhone,
    quantity: double.parse(_moneyController.text),
    payment: _paymnt,
    price: (rate ?? 0),
    unit: _unit,
    timestamp: DateTime.now().millisecondsSinceEpoch,
  );
}
  • destlat/destlong: Delivery destination coordinates
  • driverId/driverName/driverPhone: Selected driver information
  • userId/userName/userPhone: Buyer information
  • quantity: Amount ordered
  • payment: Payment method
  • price: Unit price at time of order
  • unit: Measurement unit (Truck/Tonne)
  • timestamp: Order creation time in milliseconds

​
Submitting Orders

Orders are submitted to Firebase Realtime Database: 
_requestDelivery(Order order, BuildContext context) async {
  showModal('Requesting...', context);
  String key = 'O:${DateTime.now().millisecondsSinceEpoch}';
  await databaseReference
      .child('Drivers')
      .child(order.driverId)
      .child('requests')
      .update({
    key: order.toMap(currentUserId),
  });
  await databaseReference
      .child('buyers')
      .child(currentUserId)
      .child('requests')
      .update({
    key: order.toMap(currentUserId),
  });
  Navigator.of(context).pop();
}
Orders are stored under both the driver’s and buyer’s nodes in the database for efficient querying and real-time updates.

​
Order Validation

Before submission, the system validates:
  1. Driver Selection: A driver must be selected or searched
  2. Quantity: Must be a valid number greater than 0
  3. Pricing: Rate must be successfully fetched
  4. Location: User’s current location must be available
if (_selected >= 0 &&
    rate != null &&
    double.tryParse(_moneyController.text) != null) {
  // Show confirmation dialog
} else {
  // Show validation error
}
The ordering interface is accessible from the main tab navigation: 
TabBar(
  controller: _tabController,
  tabs: [
    Tab(text: ('Chats')),
    Tab(text: ('Request')),  // Ordering tab
    Tab(text: ('Orders')),
  ],
)

​
Next Steps

Track Orders

Monitor delivery progress in real-time

Chat with Drivers

Communicate directly with delivery drivers

Build docs developers (and LLMs) love

Get started for freeTalk to us