Custom AJAX Handlers for 1C-Bitrix: Achieve Speed and Security

Custom AJAX Handlers for 1C-Bitrix

In an online store on Bitrix under load, standard AJAX requests lag: the catalog loads in 2-3 seconds, and the cart updates with a delay. The reason is the initialization of the entire kernel on every request: modules, session, templates. That's an extra 50-80 milliseconds, which turns into seconds on mass operations. The client leaves, conversion drops. We solve this with custom AJAX handlers: point initialization, direct data access, caching. Our team has over 10 years of Bitrix development experience and has successfully delivered more than 200 custom AJAX endpoints for high-traffic online stores, guaranteeing reliable performance and security. Below we break down the technique with real examples.

How to Initialize the Bitrix Kernel for AJAX?

Standard header.php initializes the entire site — modules, session, permissions, templates. For an AJAX endpoint, all that is overhead. A custom handler initializes only what's needed:

<?php
// /local/ajax/catalog-prices.php

define('NO_KEEP_STATISTIC', true);   // don't write statistics
define('NO_AGENT_STATISTIC', true);  // don't run agents
define('DisableEventsCheck', true);  // skip part of initialization

require_once $_SERVER['DOCUMENT_ROOT'] . '/bitrix/modules/main/include/prolog_before.php';

// Only necessary modules
\Bitrix\Main\Loader::includeModule('catalog');
\Bitrix\Main\Loader::includeModule('sale');

This approach reduces initialization time from 50-80 ms to 10-15 ms on a cold start. For an endpoint called 1000 times per minute, the savings are up to 70% CPU time.

How to Secure a Custom Handler?

Security relies on multiple layers. CSRF protection — mandatory check_bitrix_sessid(). Validation — each parameter is type-cast and range-checked. Rate limiting — for public endpoints we limit requests per IP (e.g., no more than 10 per second).

Example handler structure:

if ($_SERVER['REQUEST_METHOD'] !== 'POST') {
    http_response_code(405);
    die(json_encode(['error' => 'Method Not Allowed']));
}

if (!check_bitrix_sessid()) {
    http_response_code(403);
    die(json_encode(['error' => 'CSRF check failed']));
}

global $USER;
if (!$USER->IsAuthorized()) {
    http_response_code(401);
    die(json_encode(['error' => 'Unauthorized']));
}

$action = $_POST['action'] ?? '';
$result = match($action) {
    'get_price'    => getPriceAction((int)($_POST['product_id'] ?? 0)),
    'check_stock'  => checkStockAction((int)($_POST['product_id'] ?? 0)),
    default        => ['error' => 'Unknown action'],
};

header('Content-Type: application/json; charset=utf-8');
echo json_encode($result, JSON_UNESCAPED_UNICODE);

Each parameter is validated with explicit typing and permission check via CIBlockElement::GetPermission. Errors are logged in \Bitrix\Main\Diag\Debug::writeToFile; the client receives only a general message.

Rate limiting is implemented via APCu or Redis. For authorized users, the limit is higher (100 requests per minute), for anonymous users stricter (20 requests per minute). This protects against DDoS and scraping. Example of rate limiting via APCu:

$ip = $_SERVER['REMOTE_ADDR'];
$key = "rate_limit_{$ip}";
$limit = 20; // requests per minute for anonymous
$interval = 60;

if (apcu_exists($key)) {
    $count = apcu_inc($key);
    if ($count > $limit) {
        http_response_code(429);
        die(json_encode(['error' => 'Too Many Requests']));
    }
} else {
    apcu_add($key, 1, $interval);
}

Why Is a Custom Handler Faster Than Standard?

Comparison with D7 controller:

For new projects, we recommend starting with D7 controllers and switching to custom handlers only for performance-critical endpoints. We often use a hybrid approach: part of the logic on D7 for simplicity, part on custom handlers for speed.

Case: Fast Price Request Handler

From our practice: an online store needed to update prices on the catalog page in real time when selecting options. The standard catalog.price component initialized the entire kernel and responded in 200-300 ms. We wrote a custom handler that received the product ID and returned the price with discount, using a direct SQL query to the b_catalog_price table. Response time dropped to 15-20 ms. Additionally, we configured caching for 60 seconds with tagged invalidation on price change. As a result, server load dropped by 5 times, and user conversion increased by 12%. The client saved over 1 million rubles per year on server resources. Development costs are often recouped within months through such savings.

Response Caching

For rarely changing data (attributes, stock), we use Bitrix managed cache:

$cacheManager = \Bitrix\Main\Application::getInstance()->getManagedCache();
$cacheKey = "product_attrs_{$productId}";

if (!$cacheManager->read(3600, $cacheKey)) {
    $data = loadProductAttributes($productId);
    $cacheManager->set($cacheKey, $data);
} else {
    $data = $cacheManager->get($cacheKey);
}

Tagged invalidation — when a product changes, the cache is automatically cleared. This keeps data current without extra queries.

What Is Included in Custom AJAX Handler Development?

• Architecture design and endpoint selection
• Code writing with point kernel initialization
• Implementation of CSRF, authorization, validation, and rate limiting
• Response caching with tagged invalidation
• Integration with existing components and modules
• Performance and security testing
• API documentation and deployment guide
• Training for your team (on request)
• Post-delivery support (first 30 days free)

Development Timeline

Contact us for a preliminary estimate — we will calculate the timeline and cost individually. Get a consultation for your project. Write to us: we will respond within a day.

The AJAX technology is described on Wikipedia, and the Bitrix component documentation is on dev.1c-bitrix.ru.

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.