Auction System Development on 1C-Bitrix

Developing an Auction System on 1C-Bitrix

We develop auction systems on 1C-Bitrix with full integration into the trade catalog. The standard catalog and sale modules do not contain ready-made trading logic—we build it from scratch, ensuring data integrity during simultaneous bids, real-time updates, and automatic order creation. Our team has 10+ years of Bitrix development experience and has implemented auction systems for platforms with loads of up to 10,000 concurrent users.

An auction on a website is a non-trivial task: the price of a product is determined by buyer competition within a limited time. Errors in bid logic or update delays lead to financial losses. We solve these problems at the architecture level, choosing the optimal balance between performance and complexity. For example, for one project with 5000+ simultaneous lots, we used a combination of polling and aggressive caching—this reduced the database load by 40%.

Why is an auction on Bitrix a complex task?

Bitrix does not have built-in mechanisms for managing auctions. Development requires:

• Custom tables for storing bids and states
• Transactional logic to avoid race conditions
• Real-time or quasi-real-time interface updates
• Integration with 1C for synchronizing balances and prices
• Anti-fraud rules to protect against manipulation

Each item is a separate challenge. For example, with simultaneous bids from two users, without row locking in the database, both could become winners. We solve this through SELECT FOR UPDATE.

Types of Auctions

Before development, it is important to fix the business requirements by auction type:

How do we implement bid reception?

Accepting a new bid is a critical section. Several users may bid simultaneously. Without locks, race conditions will occur.

function placeBid(int $auctionId, int $userId, float $amount): BidResult
{
    // Начало транзакции с блокировкой строки аукциона
    $connection = \Bitrix\Main\Application::getConnection();
    $connection->startTransaction();

    try {
        // SELECT FOR UPDATE — блокируем строку
        $auction = $connection->query(
            "SELECT * FROM b_local_auction WHERE ID = {$auctionId} FOR UPDATE"
        )->fetch();

        // Валидации
        if ($auction['STATUS'] !== 'ACTIVE') {
            throw new \Exception('Аукцион не активен');
        }
        if (new DateTime() > new DateTime($auction['END_TIME'])) {
            throw new \Exception('Аукцион завершён');
        }
        if ($amount < $auction['CURRENT_PRICE'] + $auction['MIN_STEP']) {
            throw new \Exception('Ставка ниже минимальной: ' . ($auction['CURRENT_PRICE'] + $auction['MIN_STEP']));
        }
        if ($auction['CURRENT_WINNER_ID'] === $userId) {
            throw new \Exception('Вы уже лидируете');
        }

        // Записать ставку
        AuctionBidTable::add([
            'AUCTION_ID' => $auctionId,
            'USER_ID' => $userId,
            'AMOUNT' => $amount,
            'CREATED_AT' => new DateTime(),
        ]);

        // Обновить текущую ставку
        AuctionTable::update($auctionId, [
            'CURRENT_PRICE' => $amount,
            'CURRENT_WINNER_ID' => $userId,
            'BIDS_COUNT' => $auction['BIDS_COUNT'] + 1,
        ]);

        // Продление времени при ставке в последние минуты
        if ((new DateTime($auction['END_TIME']))->getTimestamp() - time() < 300) {
            AuctionTable::update($auctionId, [
                'END_TIME' => (new DateTime())->modify('+5 minutes'),
            ]);
        }

        $connection->commitTransaction();

        // Уведомить предыдущего лидера
        notifyOutbid($auction['CURRENT_WINNER_ID'], $auctionId, $amount);

    } catch (\Exception $e) {
        $connection->rollbackTransaction();
        throw $e;
    }
}

How do we ensure real-time updates on Bitrix?

An auction requires displaying the current bid without reloading the page. Three approaches:

Polling—the simplest: JavaScript makes an AJAX request every 5–10 seconds. Polling is 5–10 times simpler to implement than WebSocket and suits 95% of auctions.

setInterval(() => {
    fetch('/local/ajax/auction_state.php?id=' + auctionId)
        .then(r => r.json())
        .then(data => updateUI(data));
}, 5000);

Server-Sent Events (SSE)—the server sends events itself on change. Less load than polling, but more complex to set up on typical hosting.

WebSocket—maximally real-time, but requires a separate server (Node.js, Ratchet). On Bitrix hosting may be unavailable.

For most auctions, polling with an interval of 5–10 seconds is a sufficient solution.

How does anti-fraud work?

Check for one user from different accounts: analysis of IP, cookies, action history. Optional: phone verification or prepayment (blocking the amount) for accessing the auction. The minimum account must be registered at least 7 days ago and have at least one completed order.

What is included in turnkey auction development?

We provide a full package:

1. Data structure design (tables, indexes, relationships)
2. Implementation of bid logic with transactions and anti-fraud
3. User interface (lot page, bid form, timer, current status)
4. Real-time updates (polling/SSE/WebSocket as agreed)
5. Automatic auction completion, winner notifications, order creation
6. Integration with 1C via CommerceML (synchronization of balances, prices, orders)
7. Architecture and API documentation
8. Administrator training on working with auctions
9. 30-day warranty support after delivery

Estimated timelines

The cost is calculated individually and depends on complexity. We will evaluate your project for free. Contact us to discuss the details.

Review the official documentation of 1C-Bitrix to understand the platform’s capabilities. Get a consultation on your project—we will tell you how to implement an auction considering your business rules.

1C-Bitrix Module Development and Setup

The main trap of Bitrix is init.php. You add an OnBeforeIBlockElementUpdate handler there, then another one — a year later the file is 2000 lines, and on every hit all that code executes. We move business logic into full-fledged modules with D7 ORM, custom tables, and administrative interface. The module can be disabled, transferred to another project, covered with tests — none of that is possible with init.php. Our team has 10+ years of Bitrix experience, certified specialists, and a 6-month code guarantee. Request a consultation — we'll explain how to migrate legacy code to a modular architecture.

Why is init.php the worst place for business logic?

Init.php does not support class autoloading, lacks an isolated namespace, cannot be unit tested, and cannot be disabled without editing the file itself. Every handler written there runs on every request, even if not needed. In a module, you register handlers through EventManager, and they only execute when the event occurs. Performance difference: up to 3x with 10+ handlers.

Standard Modules: Typical Problems and Solutions

Information blocks. IBlock architecture is the first thing we review on any project. A classic mistake: one catalog infoblock with 80 properties, 30 of which are multiple. The b_iblock_element_property table swells to millions of rows, and CIBlockElement::GetList with filtering on three properties does a full scan. We move reference data to Highload-blocks, eliminate multiple properties where possible, and design the structure for 5x growth.

e-Store (sale). Cart business rules are a separate story. We set discount priorities to prevent two campaigns from giving 60% instead of 30%, connect payment handlers, and write custom validation via OnSaleOrderBeforeSaved.

Search. The built-in search module with morphology works up to 10–15 thousand elements. Beyond that — Elasticsearch. We configure it via the Bitrix search module API, indexing through CSearchFullText or custom indexers.

Highload-blocks for dictionaries, logs, user data — instead of bloated IBlocks. Direct queries via Bitrix\Highloadblock\HighloadBlockTable, custom tables instead of the EAV structure of standard infoblocks. A million records — no degradation.

Mail events. Configuration is not just templates in b_event_message. The key is SPF, DKIM, DMARC on the DNS, otherwise transactional emails go to spam. We check deliverability and set up bounce handling.

How to Design Infoblocks for Performance?

We use Highload-blocks for reference data (colors, sizes, manufacturers) that are not involved in complex queries. For SKUs — a separate infoblock with linking via IBLOCK_ELEMENT_PROPERTY. Enable INDEX_PROPERTY for frequently filtered properties. Tagged caching: when an element changes, only the related cache is cleared. Highload-blocks process up to 10x faster than infoblocks with multiple properties on volumes of 100,000 records.

Custom Module Development

Each module follows the structure /local/modules/vendor.modulename/:

• install/index.php — setup class, create tables via $DB->RunSQLBatch()
• lib/ — D7 ORM classes, extending Bitrix\Main\ORM\Data\DataManager
• admin/ — administrative pages using CAdminList, CAdminForm
• include.php — autoloading, event handler registration via EventManager::getInstance()->registerEventHandler()
• REST API endpoints via \Bitrix\Rest\RestManager

The module registers in the system, appears in the "Installed Solutions" list, and has its own settings at /bitrix/admin/settings.php?mid=vendor.modulename. It can be enabled, disabled, and updated through UpdateSystem or custom migration mechanics.

Examples of implemented tasks:

• Campaign management — visual condition builder via CAdminCalendar, timers via agents (CAgent::AddAgent), analytics linked to the sale module
• Cost calculator — React widget on the frontend, REST API in the module, formulas stored in a Highload-block
• Booking system — real-time calendar, locking via $DB->StartTransaction() / $DB->Commit() on concurrent requests, integration with channel manager via webhook

Components and Composite Cache

Component customization via result_modifier.php and component_epilog.php, not by editing template.php of the standard template. This way core updates are painless.

Composite cache ("Composite Site" technology) — the server sends ready HTML, bypassing PHP routing. Dynamic areas (cart, authorization) are loaded via CBitrixComponent::setFrameMode(true) and AJAX. TTFB drops to 30–50 ms. But there are caveats: not all components are compatible, $APPLICATION->ShowPanel() breaks composite, and careful markup of <div id="bx-composite-..."> is required.

What to Check Before Installing a Marketplace Module?

Before installing a module from the marketplace, an audit is mandatory. We check: SQL queries without prepared statements (hello SQL injection), direct use of $_REQUEST without filtering, use of outdated kernel API instead of D7, conflicts with the composite cache module. A module with no updates for over a year and a few dozen installations is likely a problem on the next PHP update. A typical case: a module calls CIBlockElement::GetList with no cache reset — the site crashes with 5000 elements.

Migration to D7

When upgrading PHP or switching to a new edition — refactor outdated calls:

• CIBlockElement::GetList() → Bitrix\Iblock\Elements\ElementTable::getList()
• CSaleOrder::GetList() → Bitrix\Sale\Order::getList()
• CModule::IncludeModule() → Bitrix\Main\Loader::includeModule() Testing on staging, rollback via git on issues.

According to official 1C-Bitrix documentation, D7 ORM is the recommended tool for working with data, providing type safety and automatic query generation.

Comparison: Init.php vs Module

Module Development Scope and Cost

What is included in module development?

• Technical specification and architectural plan
• Code following PSR-4 and Bitrix code style
• Unit tests (PHPUnit) for business logic
• Integration tests for events and REST API
• Installation, configuration, and API documentation
• Repository and documentation access
• Administrator training for module usage
• 6-month warranty support

Estimated timelines and complexity:

Cost is calculated individually — contact us for a project estimate.

Module Testing

Unit tests via PHPUnit cover business logic: discount calculation, validation, document generation. Mocks for Bitrix\Main\Application::getConnection() allow tests to be DB-independent. Integration tests verify event handlers on a real database — OnAfterIBlockElementAdd, OnSaleOrderSaved, etc. REST API endpoints are tested via curl or PHPUnit HTTP client. Critical for modules working with b_sale_order, b_catalog_price — where errors cost money.

Compatibility is checked on PHP 7.4, 8.0, 8.1, 8.2 and editions: Standard, Small Business, Business. We check conflicts with popular marketplace modules — they often intercept the same events. Load testing: measurements on 10K, 100K, 1M records, profiling via Xdebug for memory leaks and N+1 queries.

Practical Examples

Campaign module for an electronics chain. The built-in sale module discounts did not cover scenarios like "2+1", a gift with purchase over a certain amount, or combined conditions. We built a visual builder: marketers create rules via drag-and-drop without development tickets. Campaign calendar, auto-deactivation via agents, analytics linked to b_sale_order — conversion, average check, usage count. Time to launch a new campaign dropped from two days to half an hour.

Calculator for builders. Parameters (area, materials, number of floors) → formula → preliminary estimate → lead to CRM via CRest::call('crm.lead.add'). Regional coefficients and seasonal markups from a Highload-block, material prices from 1C exchange. The number of target leads increased by a third: clients see a breakdown before calling a manager.

Booking for a hotel chain. Real-time availability via AJAX requests to a custom table vendor_booking_slots, seasonal tariff calculation, synchronization with Booking.com via channel manager API. Room locking on concurrent booking via SELECT ... FOR UPDATE in transactions. Timezones handled via \DateTimeZone — a guest from Vladivostok and a manager from Moscow see the same picture.

We will evaluate your project within one day. Write to us — we'll tell you what is included in turnkey development. Contact us for a consultation on your project. Order a custom module development — get a ready solution with documentation and support.