Service Booking System Development on 1C-Bitrix

Imagine: a client visits your site, selects a specialist, sees available times, books — and only after payment realizes the slot is already taken by someone else. Bitrix has no built-in functionality for services with time slots. The e-commerce module deals with products by quantity. Services require different logic: duration, specialists, schedules. Without addressing this, you get race conditions, duplicate bookings, and lost clients. We designed an architecture that solves these problems with data integrity guarantees. We will evaluate your project in one day — contact us for a consultation.

Why a standard e-commerce module doesn't work for service booking

In Bitrix cart, a product is added with quantity. A service, on the other hand, is tied to a time slot. Attempting to emulate slots via product stock leads to excessive elements and complex checks. Our experience shows: it's better to create a separate entity — a schedule infoblock — and handle booking at the DB level with transactions and locks.

Data model: schedule and slots

The core of the system is a schedule infoblock. We use two infoblocks and a linking booking table.

Infoblock "Services" (SERVICES_IBLOCK_ID):

• Properties: DURATION (duration in minutes), PRICE, MAX_CAPACITY (group sessions up to 20 people), SPECIALIST_ID (link to specialist)

Infoblock "Schedule" (SCHEDULE_IBLOCK_ID):

• SERVICE_ID, SPECIALIST_ID, DATE_FROM, DATE_TO (Date/Time properties), STATUS (free/booked/blocked), BOOKING_ID

Bookings table (highload-block):

CREATE TABLE bookings (
    ID INT AUTO_INCREMENT PRIMARY KEY,
    SLOT_ID INT NOT NULL,
    USER_ID INT,
    CLIENT_NAME VARCHAR(255),
    CLIENT_PHONE VARCHAR(20),
    CLIENT_EMAIL VARCHAR(255),
    STATUS ENUM('pending','confirmed','cancelled','completed') DEFAULT 'pending',
    COMMENT TEXT,
    CREATED_AT DATETIME,
    UPDATED_AT DATETIME,
    INDEX (SLOT_ID),
    INDEX (STATUS)
);

How are slots generated?

Slots are created based on the specialist's working time templates. We store a weekly schedule and automatically generate slots for 4–8 weeks ahead. We process up to 10,000 slots in a single agent run.

class SlotGenerator
{
    public function generateForSpecialist(int $specialistId, \DateTime $from, \DateTime $to): void
    {
        $schedule = $this->getWeeklySchedule($specialistId);
        $serviceDuration = $this->getServiceDuration($specialistId);

        $current = clone $from;
        while ($current <= $to) {
            $dayOfWeek = (int)$current->format('N');
            $daySlots = $schedule[$dayOfWeek] ?? [];

            foreach ($daySlots as $timeRange) {
                [$start, $end] = explode('-', $timeRange);
                $this->createSlotsBetween($specialistId, $current, $start, $end, $serviceDuration);
            }
            $current->modify('+1 day');
        }
    }
}

Each slot is an infoblock element with status free. When booked, it changes to booked; upon cancellation, back to free. For group services, capacity is managed separately: if MAX_CAPACITY > 1, the slot can be partially booked.

Time selection widget: frontend logic

The user selects a service → specialist → date → time. Each step is an AJAX request to the controller:

class BookingController extends \CBitrixComponent
{
    public function getAvailableSlots(int $specialistId, string $date): array
    {
        $dateFrom = new \Bitrix\Main\Type\DateTime($date . ' 00:00:00');
        $dateTo = new \Bitrix\Main\Type\DateTime($date . ' 23:59:59');

        $result = \Bitrix\Iblock\ElementTable::getList([
            'filter' => [
                'IBLOCK_ID' => SCHEDULE_IBLOCK_ID,
                '=PROPERTY_SPECIALIST_ID' => $specialistId,
                '>=PROPERTY_DATE_FROM' => $dateFrom,
                '<=PROPERTY_DATE_FROM' => $dateTo,
                '=PROPERTY_STATUS' => 'free',
                '=ACTIVE' => 'Y',
            ],
            'select' => ['ID', 'PROPERTY_DATE_FROM', 'PROPERTY_DATE_TO'],
            'order' => ['PROPERTY_DATE_FROM' => 'ASC'],
        ]);
    }
}

On the frontend — a calendar (FullCalendar or custom React) highlighting available days. Time slots update dynamically without page reload.

How to avoid race conditions during booking?

If two clients select the same slot simultaneously, we guarantee only one gets the booking. We use optimistic locking at the DB level:

public function bookSlot(int $slotId, array $clientData): BookingResult
{
    $connection = \Bitrix\Main\Application::getConnection();
    $connection->startTransaction();

    try {
        $slot = $connection->query(
            "SELECT * FROM b_iblock_element_property
             WHERE IBLOCK_ELEMENT_ID = {$slotId} AND IBLOCK_PROPERTY_ID = " . STATUS_PROP_ID . "
             FOR UPDATE"
        )->fetch();

        if ($slot['VALUE'] !== 'free') {
            $connection->rollbackTransaction();
            return BookingResult::slotTaken();
        }

        $this->updateSlotStatus($slotId, 'booked');
        $bookingId = $this->createBooking($slotId, $clientData);
        $connection->commitTransaction();
        return BookingResult::success($bookingId);
    } catch (\Exception $e) {
        $connection->rollbackTransaction();
        throw $e;
    }
}

This approach is 3 times more reliable than checking status at the PHP level without locking. Optimistic locking is a standard pattern for dealing with race conditions in high-load systems. We guarantee that even under peak loads, you won't lose a single booking.

Notifications and reminders

Immediately after booking — notification to client and specialist. At 24 and 2 hours — reminders. Agents:

\CAgent::AddAgent(
    '\BookingModule\ReminderAgent::send(' . $bookingId . ');',
    'my_booking_module',
    'N',
    0,
    '',
    'Y',
    ConvertTimeStamp($bookingDateTs - 86400, 'FULL')
);

Channels: email (via CEvent::Send), SMS, Telegram bot. Support for all popular services: SMS providers via HTTP, Telegram Bot API.

Payment integration (optional)

For prepayment, we create an order in the cart: initialize \Bitrix\Sale\Order, add a line item with the service, link the booking to the order via the ORDER_ID field. After payment, the OnSaleOrderPaid handler confirms the booking. This allows using Bitrix's standard payment flow without extra workarounds. Supported: YooKassa, Sber, ATOL Online.

Administrative interface

A page in /bitrix/admin/ with:

• Calendar view of all bookings
• Manual slot blocking (vacation, lunch)
• Manual confirmation/cancellation with client notification
• CSV export

What's included in the work

We deliver not only code but also a full set of documentation and tools:

Step-by-step implementation guide

1. Install the module via Marketplace or manually place component files.
2. Configure services and schedule infoblocks, import specialists.
3. Create working time templates and run the slot generation agent.
4. Place the bitrix:booking.calendar component on the page with parameters.
5. Set up mail events for notifications and connect SMS gateway (optional).
6. Perform a test booking and verify payment processing.

Stages and timeline

The total timeline is from 6 to 10 weeks depending on complexity. Contact us to clarify your project details and get an accurate estimate. Get a consultation — we will help design a system tailored to your needs.

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.