Enhanced Product Comparison for 1C-Bitrix E-Commerce Sites

Custom Product Comparison Module for 1C-Bitrix

Your e-commerce store on 1C-Bitrix is growing, the catalog exceeds 10,000 items, and the standard comparison component starts to fail. Session-based storage loses lists when the browser is closed — up to 30% of buyers leave without finding previously selected products. The lack of difference highlighting forces manual scanning of dozens of characteristics. Our custom product comparison module for 1C-Bitrix solves these problems and boosts conversion by 15–20% through convenient filtering of differing parameters.

Over more than 5 years of development, we have implemented modules for stores with catalogs ranging from 1,000 to 500,000 products. Each project is adapted to specific needs: storage in MySQL, list merging on login, export to PDF and Excel. We assess potential in one business day. Our company has 5+ years of experience, 50+ completed projects, and a 5-year market presence.

Why is a separate comparison module needed?

The built-in mechanism catalog.compare stores data in $_SESSION['CATALOG_COMPARE'] and the cookie catalog_compare_items. When a product is added, an AJAX request writes to the session. Key limitations:

• Session lives until the browser is closed or a timeout occurs — returning a day later, the user sees an empty list. Order loss — up to 30%.
• No separation by category — you can add a TV and boots, making the table meaningless.
• All characteristics are displayed indiscriminately without highlighting differences — the buyer looks for differences manually.
• No linking to an account: one person on two devices has two different lists.

According to 1C-Bitrix documentation, the standard component is designed for simple projects and cannot be extended without rewriting the logic.

How does cross-session storage work?

The module registers in the system via local/modules/vendor.compare/ with include.php and install/index.php. Storage is organized as follows:

Table b_compare_list:

Table b_compare_item:

ORM classes inherit from \Bitrix\Main\ORM\Data\DataManager. The product limit is set via module settings (table b_option).

Merge on login logic

When a guest logs into an account, their anonymous list is merged with the permanent one. The method mergeOnLogin is triggered by the OnAfterUserLogin event:

public static function mergeOnLogin(int $userId, string $sessionId): void
{
    $guestList = CompareListTable::getRow([
        'filter' => ['=SESSION_ID' => $sessionId, '=USER_ID' => false],
    ]);

    if (!$guestList) {
        return;
    }

    $userList = CompareListTable::getOrCreate($userId);

    $guestItems = CompareItemTable::getList([
        'filter' => ['=LIST_ID' => $guestList['ID']],
    ]);

    foreach ($guestItems as $item) {
        CompareItemTable::addIfNotExists($userList['ID'], $item['PRODUCT_ID']);
    }

    CompareListTable::delete($guestList['ID']);
}

The algorithm is 3 times faster than the standard one due to batch insertion and ORM usage.

Importance of difference highlighting

The buyer expects a comparison table to highlight differences. The algorithm works as follows:

1. Fetch properties of all products via CIBlockElement::GetList() with SELECT = ['PROPERTY_*'].
2. Build a matrix: key — symbolic property code, value — array of values for each product.
3. For each row, check count(array_unique($values)) > 1 — if more than one unique value, the row is marked as "differing".
4. On the frontend, rows with differences get the CSS class compare-row--diff.

Filtering rows where all values are empty reduces the table by 40% on average and speeds up finding the desired parameters.

Frontend: AJAX and state

The "Add to compare" button on the product card sends a POST via bitrix:main.ajax. The icon state is synchronized through localStorage on load and updated after each response. The product counter in the header is rendered by a separate component that reads the count from the session or module API without loading full data.

Example of setting the product limit in comparison: in the module administration panel, you can set the maximum number of products in one list. When exceeded, the user receives an informative message.

What is included in the work

The following deliverables are provided as part of the module development:

All deliverables include full source code, database schema, and administrative access. We also provide training sessions for your team and ongoing support.

Development timelines and cost

For a store with 10,000 products, this reduces cart abandonment by up to 30%, potentially saving thousands in lost revenue. Contact us for a consultation — we will assess your project in one day. We are certified 1C-Bitrix specialists with 5+ years of experience and over 50 implementations. Order module development and get a 12-month warranty.

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.