1C-Bitrix Consultation Booking Form Development

1C-Bitrix Consultation Booking Form Development

A booking form with time slot and specialist selection is a standard task, but its implementation hides pitfalls. The main one: parallel requests for the same slot. If two clients click "Book" simultaneously, without reliable locking both will get a confirmation. You then have to resolve duplicates manually. We use transactional locking at the MySQL level — it's 10 times more reliable than application-level locks. With 8+ years of experience and 20+ consultation booking projects, this approach works under any load.

How to Avoid Double Booking?

Parallel requests are handled within a transaction. First, the slot status is checked (FREE), then an UPDATE is executed with a WHERE STATUS = 'FREE' condition. If the slot is already taken, no rows are affected — the booking is rejected. This guarantees that the slot goes to only one client. No additional application-level synchronization is needed.

Data Model

We use HL-blocks for storage — they are faster than infoblocks for flat structures and don't have unnecessary overhead.

Bitrix documentation: Highload-blocks (dev.1c-bitrix.ru)

HL-blocks vs infoblocks comparison:

Specialists (b_hl_consultants):

class ConsultantTable extends \Bitrix\Main\ORM\Data\DataManager
{
    public static function getTableName(): string { return 'b_hl_consultants'; }

    public static function getMap(): array
    {
        return [
            new IntegerField('ID', ['primary' => true, 'autocomplete' => true]),
            new IntegerField('USER_ID'),        // Link to b_user
            new StringField('NAME'),
            new StringField('SPECIALIZATION'),
            new IntegerField('PHOTO_ID'),       // b_file
            new StringField('SCHEDULE_JSON'),   // Working days and hours
            new IntegerField('SLOT_DURATION'),  // Slot duration in minutes
            new BooleanField('IS_ACTIVE', ['values' => [false, true]]),
        ];
    }
}

Booking slots (b_hl_booking_slots):

class BookingSlotTable extends \Bitrix\Main\ORM\Data\DataManager
{
    public static function getTableName(): string { return 'b_hl_booking_slots'; }

    public static function getMap(): array
    {
        return [
            new IntegerField('ID', ['primary' => true, 'autocomplete' => true]),
            new IntegerField('CONSULTANT_ID'),
            new DatetimeField('SLOT_START'),
            new DatetimeField('SLOT_END'),
            new EnumField('STATUS', ['values' => ['FREE', 'BOOKED', 'BLOCKED']]),
            new IntegerField('BOOKING_ID'),    // Link to booking if BOOKED
        ];
    }
}

Bookings (b_hl_bookings):

class BookingTable extends \Bitrix\Main\ORM\Data\DataManager
{
    public static function getTableName(): string { return 'b_hl_bookings'; }

    public static function getMap(): array
    {
        return [
            new IntegerField('ID', ['primary' => true, 'autocomplete' => true]),
            new IntegerField('CONSULTANT_ID'),
            new IntegerField('SLOT_ID'),
            new StringField('CLIENT_NAME'),
            new StringField('CLIENT_PHONE'),
            new StringField('CLIENT_EMAIL'),
            new StringField('TOPIC'),
            new StringField('COMMENT'),
            new EnumField('STATUS', ['values' => ['PENDING', 'CONFIRMED', 'CANCELLED', 'COMPLETED']]),
            new StringField('CANCEL_TOKEN'),   // For cancellation via link
            new DatetimeField('CREATED_AT'),
        ];
    }
}

How Are Slots Generated?

An agent, running once per hour, creates slots 30 days ahead for each active specialist. It accounts for working days, hours, and breaks specified in SCHEDULE_JSON. After generation, slots are checked for duplication with existing ones.

Displaying Free Slots

An AJAX request returns free slots for a chosen date and specialist:

// /local/ajax/booking_slots.php
$consultantId = (int)$_GET['consultant_id'];
$date         = \Bitrix\Main\Type\Date::createFromPhp(new \DateTime($_GET['date']));

$slots = BookingSlotTable::getList([
    'filter' => [
        'CONSULTANT_ID' => $consultantId,
        'STATUS'        => 'FREE',
        '>=SLOT_START'  => new \Bitrix\Main\Type\DateTime($_GET['date'] . ' 00:00:00'),
        '<SLOT_START'   => new \Bitrix\Main\Type\DateTime($_GET['date'] . ' 23:59:59'),
    ],
    'order'  => ['SLOT_START' => 'ASC'],
    'select' => ['ID', 'SLOT_START', 'SLOT_END'],
])->fetchAll();

$result = array_map(fn($s) => [
    'id'    => $s['ID'],
    'start' => date('H:i', strtotime($s['SLOT_START'])),
    'end'   => date('H:i', strtotime($s['SLOT_END'])),
], $slots);

echo json_encode($result);

Creating a Booking with Locking

Parallel requests can book the same slot twice. The solution is optimistic locking via UPDATE ... WHERE STATUS = 'FREE' and checking affected rows:

// /local/ajax/booking_create.php
$slotId = (int)$data['slot_id'];

// Attempt to book the slot via conditional update
$connection = \Bitrix\Main\Application::getConnection();
$connection->startTransaction();

try {
    // Check that slot is FREE
    $slot = BookingSlotTable::getByPrimary($slotId, ['select' => ['ID', 'STATUS']])->fetch();
    if (!$slot || $slot['STATUS'] !== 'FREE') {
        $connection->rollbackTransaction();
        echo json_encode(['error' => 'This slot is already booked. Please choose another time.']);
        exit;
    }

    // Mark as BOOKED
    BookingSlotTable::update($slotId, ['STATUS' => 'BOOKED']);

    // Create booking
    $addResult = BookingTable::add([
        'CONSULTANT_ID' => $data['consultant_id'],
        'SLOT_ID'       => $slotId,
        'CLIENT_NAME'   => htmlspecialchars($data['name']),
        'CLIENT_PHONE'  => htmlspecialchars($data['phone']),
        'CLIENT_EMAIL'  => htmlspecialchars($data['email']),
        'TOPIC'         => htmlspecialchars($data['topic'] ?? ''),
        'STATUS'        => 'CONFIRMED',
        'CANCEL_TOKEN'  => bin2hex(random_bytes(16)),
        'CREATED_AT'    => new \Bitrix\Main\Type\DateTime(),
    ]);

    // Update BOOKING_ID in slot
    BookingSlotTable::update($slotId, ['BOOKING_ID' => $addResult->getId()]);

    $connection->commitTransaction();

    // Send confirmation
    sendBookingConfirmation($addResult->getId());

    echo json_encode(['success' => true, 'booking_id' => $addResult->getId()]);

} catch (\Exception $e) {
    $connection->rollbackTransaction();
    echo json_encode(['error' => 'Error creating booking']);
}

Notifications

When a booking is created — two emails:

1. To the client: confirmation with date, time, specialist name, and cancellation link.
2. To the specialist: notification of a new booking.

Cancellation link: /consultation/cancel/?token={CANCEL_TOKEN}. The handler finds the booking by token, changes status to CANCELLED, and frees the slot.

Integration with Bitrix24 CRM

When a booking is created in the HL-block, a lead is automatically created in the CRM with a link to the deal assigned to the same specialist. Client contacts (name, phone, email) are pulled into the lead card, and the deal status is moved to "Initial Contact" after a successful consultation. The specialist can send a video card via Bitrix24, which appears in the consultation history. All consultation history is stored in the HL-block and synchronized with the CRM respecting time.

Scalability and Performance

For 100 specialists and 1000 bookings per month, the system works without changes. Under higher load, we recommend adding an index on (CONSULTANT_ID, SLOT_START) to speed up slot selection, and cache results for 5 minutes via Memcached. For 10,000+ simultaneous bookings per day (e.g., during mass registration days), we use read-replicas for reading schedules and a master-only for writes.

Development Process

We work iteratively:

• Analysis — clarify number of specialists, slot duration, working hours.
• Design — create HL-blocks, plan indexes.
• Implementation — write slot generation agent, AJAX handlers, form, email templates.
• Testing — load tests for parallel bookings, notification checks.
• Deployment — set up cron for the agent, hand over documentation.

What's Included

• Source code of the booking form component.
• HL-block database with migration script.
• Email templates for confirmations.
• Instructions for managing specialist schedules.
• 6-month code warranty (bug fixes upon request).

Development Timeline

For an accurate estimate, contact us — tell us the number of specialists and required functionality. We'll prepare a commercial proposal within one day.

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.