Sub-Unit Prices Implementation Guide

By Simenson Technologies Ltd

This guide provides step-by-step instructions for implementing sub-unit pricing functionality in a Laravel-based POS application. Sub-unit pricing allows products to have different fixed prices when sold in different units (e.g., piece, box, carton).

Overview
Prerequisites
Step 1: Database Migration
Step 2: Model Configuration
Step 3: Backend Logic (ProductUtil)
Step 4: Controller Changes
Step 5: Frontend Views
Step 6: POS Integration
Step 7: Testing
Variation-Level Sub-Unit Prices (Optional)

Overview

What are Sub-Unit Prices?

Sub-unit prices allow you to set fixed selling prices for different units of measurement. For example:

A product's default price might be $5 per piece
But when sold by the box (12 pieces), you want to charge $50 (not $60)
When sold by the carton (10 boxes), you want to charge $450 (not $500)

This feature is stored as a JSON field on the products table and optionally on the variations table.

Architecture

Storage: products.sub_unit_prices (JSON) stores {unit_id: price} pairs
Model: Laravel automatically casts JSON to array using $casts
Retrieval: ProductUtil::getDetailsFromVariation() returns product with sub-unit prices
Display: Views render sub-unit dropdowns with data-sub_unit_price attributes
Processing: POS/transaction logic reads sub-unit prices when calculating line totals

Prerequisites

Before implementing sub-unit prices, ensure:

Sub-units are enabled in product settings: Navigate to Settings → Business Settings → Product Settings and enable the "Enable Sub Units" option
Your application has a units table with unit definitions
Products can have unit_id (primary unit) and optionally secondary_unit_id
Sub-units are already configured (relationships between units, e.g., 1 box = 12 pieces)
You have a method to retrieve sub-units for a product (e.g., ProductUtil::getSubUnits())

Step 1: Database Migration

Migration 1: Add `sub_unit_ids` Column

This column stores which sub-units are available for the product.

Create migration:

php artisan make:migration add_sub_unit_columns_to_products --table=products

File: database/migrations/2025_10_06_000001_add_sub_unit_columns_to_products.php

<?php

use Illuminate\Database\Migrations\Migration;
use Illuminate\Database\Schema\Blueprint;
use Illuminate\Support\Facades\Schema;

return new class extends Migration
{
    /**
     * Run the migrations.
     *
     * @return void
     */
    public function up()
    {
        Schema::table('products', function (Blueprint $table) {
            if (!Schema::hasColumn('products', 'sub_unit_ids')) {
                $table->json('sub_unit_ids')->nullable()->after('secondary_unit_id');
            }
            if (!Schema::hasColumn('products', 'sub_unit_prices')) {
                $table->json('sub_unit_prices')->nullable()->after('sub_unit_ids');
            }
        });
    }

    /**
     * Reverse the migrations.
     *
     * @return void
     */
    public function down()
    {
        Schema::table('products', function (Blueprint $table) {
            if (Schema::hasColumn('products', 'sub_unit_prices')) {
                $table->dropColumn('sub_unit_prices');
            }
            if (Schema::hasColumn('products', 'sub_unit_ids')) {
                $table->dropColumn('sub_unit_ids');
            }
        });
    }
};

Migration 2: Add `sub_unit_prices` Column (Alternative)

If you already have sub_unit_ids and only need to add prices:

File: database/migrations/2025_10_05_121933_add_sub_unit_prices_to_products_table.php

<?php

use Illuminate\Database\Migrations\Migration;
use Illuminate\Database\Schema\Blueprint;
use Illuminate\Support\Facades\Schema;

class AddSubUnitPricesToProductsTable extends Migration
{
    /**
     * Run the migrations.
     *
     * @return void
     */
    public function up()
    {
        Schema::table('products', function (Blueprint $table) {
            $table->json('sub_unit_prices')->nullable()->after('sub_unit_ids');
        });
    }

    /**
     * Reverse the migrations.
     *
     * @return void
     */
    public function down()
    {
        Schema::table('products', function (Blueprint $table) {
            $table->dropColumn('sub_unit_prices');
        });
    }
}

Run Migrations

php artisan migrate

Verify the columns exist:

php artisan tinker
>>> Schema::hasColumn('products', 'sub_unit_prices')
=> true

Step 2: Model Configuration

Update Product Model

Add JSON casting for the new columns.

File: app/Product.php

<?php

namespace App;

use Illuminate\Database\Eloquent\Model;

class Product extends Model
{
    protected $guarded = ['id'];

    /**
     * The attributes that should be cast to native types.
     *
     * @var array
     */
    protected $casts = [
        'sub_unit_ids' => 'array',
        'sub_unit_prices' => 'array',
    ];

    // ... rest of your model code
}

Why cast to array?

Laravel automatically converts JSON strings to PHP arrays when accessing
When saving, arrays are automatically converted back to JSON
This prevents issues with accessing $product->sub_unit_prices[$unit_id]

Step 3: Backend Logic (ProductUtil)

Ensure Sub-Unit Prices Are Decoded

When using database queries with joins (not Eloquent models), JSON fields might be returned as strings. Add defensive decoding.

File: app/Utils/ProductUtil.php

Find the method getDetailsFromVariation() and ensure it includes:

public function getDetailsFromVariation($variation_id, $business_id, $location_id = null,
    $check_qty = true, $user = null, $check_enable_stock = true)
{
    // ... existing query code that selects p.sub_unit_prices ...

    $query = Variation::join('products as p', 'variations.product_id', '=', 'p.id')
        ->join('product_variations as pv', 'variations.product_variation_id', '=', 'pv.id')
        // ... other joins ...
        ->select(
            // ... other fields ...
            'p.sub_unit_prices',
            // ... other fields ...
        )
        ->where('variations.id', $variation_id);

    $product = $query->firstOrFail();

    // IMPORTANT: Decode JSON string to array when using raw queries
    if (isset($product->sub_unit_prices) && is_string($product->sub_unit_prices)) {
        $decoded = json_decode($product->sub_unit_prices, true);
        $product->sub_unit_prices = is_array($decoded) ? $decoded : [];
    }

    // ... rest of the method

    return $product;
}

Add Price Calculation Logic

Ensure sub-unit prices override multiplier-based calculations when set.

File: app/Utils/ProductUtil.php

Find or add to the method that calculates sell prices based on sub-units:

public function calculateSubUnitSellPrice($sell_line, $sub_unit_id)
{
    // Check for fixed price for sub unit and return early
    $sub_unit_price_data = $sell_line->product->sub_unit_prices;
    if (!empty($sub_unit_price_data[$sub_unit_id])) {
        $sell_line->sell_price_inc_tax = $sub_unit_price_data[$sub_unit_id];
        return $sell_line;
    }

    // Otherwise, use multiplier-based calculation
    // ... existing multiplier logic ...

    return $sell_line;
}

Step 4: Controller Changes

ProductController - Store Method

Handle saving sub-unit prices when creating a product.

File: app/Http/Controllers/ProductController.php

In the store() method:

public function store(Request $request)
{
    try {
        $business_id = $request->session()->get('user.business_id');

        // ... existing validation and product creation code ...

        // Prepare product details array
        $product_details = [
            'name' => $request->input('name'),
            'business_id' => $business_id,
            // ... other fields ...
            'sub_unit_ids' => !empty($request->input('sub_unit_ids'))
                ? $request->input('sub_unit_ids')
                : null,
        ];

        // Handle sub-unit prices
        if (!empty($request->input('product_sub_unit_prices'))) {
            $sub_unit_prices = [];
            foreach ($request->input('product_sub_unit_prices') as $unit_id => $price) {
                if (!empty($price)) {
                    $sub_unit_prices[$unit_id] = $this->productUtil->num_uf($price);
                }
            }
            // Store as array; Product model will cast to JSON when saving
            $product_details['sub_unit_prices'] = !empty($sub_unit_prices)
                ? $sub_unit_prices
                : null;
        }

        $product = Product::create($product_details);

        // ... rest of product creation logic ...

    } catch (\Exception $e) {
        // ... error handling ...
    }
}

ProductController - Update Method

Handle updating sub-unit prices when editing a product.

File: app/Http/Controllers/ProductController.php

In the update() method:

public function update(Request $request, $id)
{
    try {
        $business_id = $request->session()->get('user.business_id');

        // ... existing validation ...

        $product = Product::where('business_id', $business_id)
            ->where('id', $id)
            ->firstOrFail();

        // ... update other fields ...

        $product->sub_unit_ids = !empty($request->input('sub_unit_ids'))
            ? $request->input('sub_unit_ids')
            : null;

        // Save fixed sub-unit prices
        if (!empty($request->input('product_sub_unit_prices'))) {
            $sub_unit_prices = [];
            foreach ($request->input('product_sub_unit_prices') as $unit_id => $price) {
                if (!empty($price)) {
                    $sub_unit_prices[$unit_id] = $this->productUtil->num_uf($price);
                }
            }
            $product->sub_unit_prices = !empty($sub_unit_prices)
                ? $sub_unit_prices
                : null;
        } else {
            $product->sub_unit_prices = null;
        }

        $product->save();

        // ... rest of update logic ...

    } catch (\Exception $e) {
        // ... error handling ...
    }
}

Add to Quick Add Export Fields (Optional)

If you support quick add or export functionality:

File: app/Http/Controllers/ProductController.php

private function productExportFields()
{
    return [
        'name',
        'sku',
        // ... other fields ...
        'product_sub_unit_prices'
    ];
}

Step 5: Frontend Views

Product Create/Edit Form

Add UI to select sub-units and enter fixed prices.

File: resources/views/product/create.blade.php and resources/views/product/edit.blade.php

Add this section after the sub-unit selection dropdown:

<div class="col-sm-4 @if(!session('business.enable_sub_units')) hide @endif">
    <div class="form-group">
        {!! Form::label('sub_unit_ids', __('lang_v1.related_sub_units') . ':') !!}
        @show_tooltip(__('lang_v1.sub_units_tooltip'))

        {!! Form::select('sub_unit_ids[]', [],
            !empty($product->sub_unit_ids) ? $product->sub_unit_ids : null,
            ['class' => 'form-control select2', 'multiple', 'id' => 'sub_unit_ids']); !!}
    </div>
</div>

<div class="col-sm-12">
    <div id="sub_unit_prices_div" class="hide">
        <br>
        <div class="table-responsive">
            <table class="table table-bordered add-product-price-table table-condensed">
                <thead>
                    <tr>
                        <th>@lang('lang_v1.related_sub_units')</th>
                        <th>@lang('product.selling_price') (@lang('product.inc_of_tax'))</th>
                    </tr>
                </thead>
                <tbody id="sub_unit_prices_body">
                </tbody>
            </table>
        </div>
    </div>
</div>

JavaScript to Populate Sub-Unit Price Inputs

Add this script at the bottom of create.blade.php and edit.blade.php:

@section('javascript')
<script src="{{ asset('js/product.js?v=' . $asset_v) }}"></script>

<script type="text/javascript">
$(document).ready(function(){
    // Helper to return localized inc/ex label depending on selected tax type
    function getSubUnitPriceSuffix() {
        var taxType = $('select[name="tax_type"]').val();
        return taxType === 'inclusive' ? '@lang('product.inc_of_tax')' : '@lang('product.exc_of_tax')';
    }

    function updateSubUnitPriceHeader() {
        var suffix = getSubUnitPriceSuffix();
        $('#sub_unit_prices_div').find('table thead th').eq(1).html("@lang('product.selling_price') (" + suffix + ")");
    }

    // Update placeholders of existing inputs
    function updateSubUnitPlaceholders() {
        var suffix = getSubUnitPriceSuffix();
        $('#sub_unit_prices_body').find('input').each(function() {
            $(this).attr('placeholder', "@lang('product.selling_price') (" + suffix + ")");
        });
    }

    // Hook tax type change to update header/placeholders
    $('select[name="tax_type"]').on('change', function() {
        updateSubUnitPriceHeader();
        updateSubUnitPlaceholders();
    });

    // Initialize header on load
    updateSubUnitPriceHeader();

    $('select#sub_unit_ids').on('change', function() {
        var sub_unit_prices_div = $('#sub_unit_prices_div');
        var sub_unit_prices_body = $('#sub_unit_prices_body');
        sub_unit_prices_body.empty();

        if ($(this).val() && $(this).val().length > 0) {
            sub_unit_prices_div.removeClass('hide');
            $(this).find('option:selected').each(function() {
                var unit_id = $(this).val();
                var unit_name = $(this).text();
                var suffix = getSubUnitPriceSuffix();

                @if(!empty($product->sub_unit_prices))
                var existing_price = {!! json_encode($product->sub_unit_prices) !!}[unit_id] || '';
                @else
                var existing_price = '';
                @endif

                var new_row = `
                    <tr>
                        <td>${unit_name}</td>
                        <td>
                            <input type="text"
                                   name="product_sub_unit_prices[${unit_id}]"
                                   class="form-control input_number"
                                   placeholder="@lang('product.selling_price') (${suffix})"
                                   value="${existing_price}">
                        </td>
                    </tr>
                `;
                sub_unit_prices_body.append(new_row);
            });
            __currency_convert_recursively(sub_unit_prices_body);
        } else {
            sub_unit_prices_div.addClass('hide');
        }
    });

    // Trigger change on page load to populate existing data
    @if(!empty($product->sub_unit_ids))
    $('select#sub_unit_ids').trigger('change');
    @endif
});
</script>
@endsection

Product Details View

Display sub-unit prices in the product details modal/page.

File: resources/views/product/partials/single_product_details.blade.php

After displaying the selling price:

<td>
    <span class="display_currency" data-currency_symbol="true">
        {{ $variation->sell_price_inc_tax }}
    </span>

    @php
        $business_id = session()->get('user.business_id');
        $sub_units = app(\App\Utils\ProductUtil::class)->getSubUnits($business_id, $product->unit_id, true, $product->id);
        $sub_unit_prices = $product->sub_unit_prices ?? [];
    @endphp

    @if(!empty($sub_unit_prices) && count($sub_unit_prices) > 0)
        <br>
        <small class="text-muted">
        @foreach($sub_units as $u_id => $u)
            @if(isset($sub_unit_prices[$u_id]) && $sub_unit_prices[$u_id] !== null && $sub_unit_prices[$u_id] !== '')
                <strong>{{ $u['name'] }}</strong>:
                <span class="display_currency" data-currency_symbol="true">
                    {{ $sub_unit_prices[$u_id] }}
                </span>@if(!$loop->last), @endif
            @endif
        @endforeach
        </small>
    @endif
</td>

Step 6: POS Integration

POS Product Row

Update the POS product row to include sub-unit prices in data attributes.

File: resources/views/sale_pos/product_row.blade.php

In the sub-unit dropdown:

<input type="hidden" name="products[{{$row_count}}][product_unit_id]" value="{{$product->unit_id}}">

@if(count($sub_units) > 0)
    <br>
    <select name="products[{{$row_count}}][sub_unit_id]" class="form-control input-sm sub_unit">
        @foreach($sub_units as $key => $value)
            <option value="{{$key}}"
                    data-multiplier="{{$value['multiplier']}}"
                    data-unit_name="{{$value['name']}}"
                    data-allow_decimal="{{$value['allow_decimal']}}"
                    data-sub_unit_price="{{ isset($product->sub_unit_prices[$key]) ? (float)$product->sub_unit_prices[$key] : '' }}"
                    @if(!empty($product->sub_unit_id) && $product->sub_unit_id == $key) selected @endif>
                {{ $value['name'] }}
            </option>
        @endforeach
    </select>
@endif

Important: Cast to (float) to ensure JavaScript receives a numeric string, not a JSON-encoded value.

JavaScript to Handle Sub-Unit Selection

File: public/js/pos.js or inline in POS view:

$(document).on('change', 'select.sub_unit', function() {
    var $row = $(this).closest('tr');
    var selected_option = $(this).find('option:selected');
    var sub_unit_price = selected_option.data('sub_unit_price');

    if (sub_unit_price && sub_unit_price !== '') {
        // Use fixed sub-unit price
        $row.find('input.pos_unit_price_inc_tax').val(sub_unit_price);
        pos_each_row($row); // Recalculate row totals
    } else {
        // Use multiplier-based calculation
        var multiplier = parseFloat(selected_option.data('multiplier')) || 1;
        var base_price = parseFloat($row.find('input.base_unit_sell_price').val()) || 0;
        var unit_price = base_price * multiplier;
        $row.find('input.pos_unit_price_inc_tax').val(unit_price);
        pos_each_row($row); // Recalculate row totals
    }
});

Step 7: Testing

Manual Testing Checklist

Create Product with Sub-Unit Prices
- Create a new product
- Set base unit (e.g., Piece)
- Select sub-units (e.g., Box, Carton)
- Enter fixed prices for each sub-unit
- Save and verify database entry

Verify Database Storage

php artisan tinker
>>> $product = App\Product::find(1);
>>> $product->sub_unit_prices
=> [
     "2" => "50.00",
     "3" => "450.00"
   ]

Edit Product Sub-Unit Prices
- Edit an existing product
- Modify sub-unit prices
- Save and verify changes persist
POS Transaction
- Open POS
- Add product to cart
- Change sub-unit dropdown
- Verify price updates to fixed sub-unit price (not multiplier-based)
- Complete sale and check transaction details
Product Details View
- View product details modal
- Verify sub-unit prices are displayed correctly

Unit Test Example

File: tests/Feature/SubUnitPriceTest.php

<?php

namespace Tests\Feature;

use Tests\TestCase;
use App\Product;
use App\Business;
use App\User;

class SubUnitPriceTest extends TestCase
{
    public function test_product_stores_sub_unit_prices()
    {
        $user = User::factory()->create();
        $this->actingAs($user);

        $response = $this->post('/products', [
            'name' => 'Test Product',
            'type' => 'single',
            'unit_id' => 1,
            'sub_unit_ids' => [2, 3],
            'product_sub_unit_prices' => [
                2 => '50.00',
                3 => '450.00'
            ],
            // ... other required fields
        ]);

        $response->assertStatus(200);

        $product = Product::where('name', 'Test Product')->first();
        $this->assertNotNull($product->sub_unit_prices);
        $this->assertEquals('50.00', $product->sub_unit_prices[2]);
        $this->assertEquals('450.00', $product->sub_unit_prices[3]);
    }
}

Variation-Level Sub-Unit Prices (Optional)

If you need different sub-unit prices per variation (e.g., Red Box costs $50, Blue Box costs $55), follow these additional steps.

1. Migration for Variations Table

php artisan make:migration add_sub_unit_prices_to_variations --table=variations

File: database/migrations/YYYY_MM_DD_add_sub_unit_prices_to_variations.php

<?php

use Illuminate\Database\Migrations\Migration;
use Illuminate\Database\Schema\Blueprint;
use Illuminate\Support\Facades\Schema;

class AddSubUnitPricesToVariations extends Migration
{
    public function up()
    {
        Schema::table('variations', function (Blueprint $table) {
            $table->json('sub_unit_prices')->nullable()->after('sell_price_inc_tax');
        });
    }

    public function down()
    {
        Schema::table('variations', function (Blueprint $table) {
            $table->dropColumn('sub_unit_prices');
        });
    }
}

2. Update Variation Model

File: app/Variation.php

class Variation extends Model
{
    protected $casts = [
        'sub_unit_prices' => 'array',
        // ... other casts
    ];
}

3. Modify ProductUtil Logic

File: app/Utils/ProductUtil.php

In getDetailsFromVariation(), prefer variation-level prices:

public function getDetailsFromVariation($variation_id, ...)
{
    // ... existing query ...

    $product = $query->firstOrFail();

    // Get variation
    $variation = Variation::find($variation_id);

    // Prefer variation-level sub_unit_prices when present
    if (!empty($variation->sub_unit_prices) && is_array($variation->sub_unit_prices) && count($variation->sub_unit_prices) > 0) {
        // Merge: variation overrides product-level
        $product->sub_unit_prices = array_merge(
            (array) $product->sub_unit_prices,
            (array) $variation->sub_unit_prices
        );
    }

    // Defensive JSON decode
    if (isset($product->sub_unit_prices) && is_string($product->sub_unit_prices)) {
        $decoded = json_decode($product->sub_unit_prices, true);
        $product->sub_unit_prices = is_array($decoded) ? $decoded : [];
    }

    return $product;
}

4. Controller Changes for Variation Prices

File: app/Http/Controllers/ProductController.php

In update() method, after saving variations:

if ($request->has('variation_sub_unit_prices')) {
    foreach ($request->input('variation_sub_unit_prices') as $variation_id => $prices) {
        $variation = \App\Variation::find($variation_id);
        if ($variation) {
            $variation->sub_unit_prices = array_filter($prices, function ($v) {
                return $v !== null && $v !== '';
            });
            $variation->save();
        }
    }
}

5. View Changes for Variation Prices

File: resources/views/product/partials/edit_product_variation_row.blade.php

Add sub-unit price inputs per variation:

@php $sub_units = $product->sub_unit_ids ?? []; @endphp
@if(count($sub_units) > 0)
    <table class="table table-condensed">
        <thead>
            <tr>
                <th>Sub Unit</th>
                <th>@lang('product.selling_price') (@lang('product.inc_of_tax'))</th>
            </tr>
        </thead>
        <tbody>
        @foreach($sub_units as $unit_id)
            @php
                $unit = \App\Unit::find($unit_id);
                $unit_name = $unit ? $unit->short_name : '';
            @endphp
            <tr>
                <td>{{ $unit_name }}</td>
                <td>
                    <input type="text"
                           name="variation_sub_unit_prices[{{ $variation->id }}][{{ $unit_id }}]"
                           value="{{ isset($variation->sub_unit_prices[$unit_id]) ? $variation->sub_unit_prices[$unit_id] : '' }}"
                           class="form-control input_number">
                </td>
            </tr>
        @endforeach
        </tbody>
    </table>
@endif

Troubleshooting

Issue: Sub-unit prices not saving

Check:

Verify $fillable or $guarded in Product model allows sub_unit_prices
Check browser console for JavaScript errors
Inspect $request->input('product_sub_unit_prices') in controller
Ensure num_uf() method exists in your ProductUtil

Issue: Prices showing as JSON string in views

Solution: Ensure model has proper casting:

protected $casts = [
    'sub_unit_prices' => 'array',
];

Issue: POS not using sub-unit prices

Check:

Verify data-sub_unit_price attribute is populated correctly
Check JavaScript console for errors
Ensure (float) casting in blade: data-sub_unit_price="{{ (float)$price }}"
Verify ProductUtil::getDetailsFromVariation() returns decoded array

Issue: Tax type mismatch (inc vs exc)

Solution:

Clarify if stored prices are inclusive or exclusive
Use tax_type field to determine
Convert at render time if needed using ProductUtil tax helpers

Best Practices

Always validate prices: Use num_uf() to unformat user input
Defensive coding: Check if sub_unit_prices exists and is array before accessing
Fallback logic: If sub-unit price not set, use multiplier calculation
Data migration: When adding feature to existing products, consider copying product-level prices to variations
Clear cache: After migration, run php artisan cache:clear and php artisan view:clear
Database backups: Always backup before running migrations in production

Summary

This implementation provides:

✅ Database schema for storing sub-unit prices (JSON)
✅ Model casting for automatic JSON ↔ array conversion
✅ Backend logic to retrieve and apply sub-unit prices
✅ Controller handling for create/update operations
✅ Frontend UI to manage sub-unit prices
✅ POS integration with dynamic pricing
✅ Optional variation-level price overrides

The system is backward compatible: if no sub-unit price is set, the application falls back to multiplier-based calculations.

References

Original implementation discussion: varation patch for sub unit.md
Migrations: database/migrations/2025_10_05_*.php and 2025_10_06_*.php
Product model: app/Product.php
ProductUtil: app/Utils/ProductUtil.php
ProductController: app/Http/Controllers/ProductController.php
Views: resources/views/product/create.blade.php and sale_pos/product_row.blade.php

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Table of Contents​

Overview​

What are Sub-Unit Prices?​

Architecture​

Prerequisites​

Step 1: Database Migration​

Migration 1: Add sub_unit_ids Column​

Migration 2: Add sub_unit_prices Column (Alternative)​

Run Migrations​

Step 2: Model Configuration​

Update Product Model​

Step 3: Backend Logic (ProductUtil)​

Ensure Sub-Unit Prices Are Decoded​

Add Price Calculation Logic​

Step 4: Controller Changes​

ProductController - Store Method​

ProductController - Update Method​

Add to Quick Add Export Fields (Optional)​

Step 5: Frontend Views​

Product Create/Edit Form​

JavaScript to Populate Sub-Unit Price Inputs​

Product Details View​

Step 6: POS Integration​

POS Product Row​

JavaScript to Handle Sub-Unit Selection​

Step 7: Testing​

Manual Testing Checklist​

Unit Test Example​

Variation-Level Sub-Unit Prices (Optional)​

1. Migration for Variations Table​

2. Update Variation Model​

3. Modify ProductUtil Logic​

4. Controller Changes for Variation Prices​

5. View Changes for Variation Prices​

Troubleshooting​

Issue: Sub-unit prices not saving​

Issue: Prices showing as JSON string in views​

Issue: POS not using sub-unit prices​

Issue: Tax type mismatch (inc vs exc)​

Best Practices​

Summary​

References​

Table of Contents

Overview

What are Sub-Unit Prices?

Architecture

Prerequisites

Step 1: Database Migration

Migration 1: Add `sub_unit_ids` Column

Migration 2: Add `sub_unit_prices` Column (Alternative)

Run Migrations

Step 2: Model Configuration

Update Product Model

Step 3: Backend Logic (ProductUtil)

Ensure Sub-Unit Prices Are Decoded

Add Price Calculation Logic

Step 4: Controller Changes

ProductController - Store Method

ProductController - Update Method

Add to Quick Add Export Fields (Optional)

Step 5: Frontend Views

Product Create/Edit Form

JavaScript to Populate Sub-Unit Price Inputs

Product Details View

Step 6: POS Integration

POS Product Row

JavaScript to Handle Sub-Unit Selection

Step 7: Testing

Manual Testing Checklist

Unit Test Example

Variation-Level Sub-Unit Prices (Optional)

1. Migration for Variations Table

2. Update Variation Model

3. Modify ProductUtil Logic

4. Controller Changes for Variation Prices

5. View Changes for Variation Prices

Troubleshooting

Issue: Sub-unit prices not saving

Issue: Prices showing as JSON string in views

Issue: POS not using sub-unit prices

Issue: Tax type mismatch (inc vs exc)

Best Practices

Summary

References