Shopware Data Layer Setup for GTM and GA4

Understanding and implementing Shopware 6 data layer structure for Google Tag Manager integration.

This guide covers how to implement and use a data layer structure for Shopware 6 that works seamlessly with Google Tag Manager (GTM).

Prerequisites: GTM must be installed. See Install Google Tag Manager

What is a Data Layer?

The data layer is a JavaScript object that holds data about the page, user, products, and events. GTM reads from this data layer to populate tags with dynamic values.

Example data layer:

window.dataLayer = window.dataLayer || [];
window.dataLayer.push({
    'event': 'page_view',
    'page_type': 'product',
    'product_id': '12345',
    'product_name': 'Running Shoes',
    'price': 79.99,
    'currency': 'EUR'
});

Basic Data Layer Implementation

Initialize Data Layer

Add to your theme's base.html.twig before GTM code:

{% block base_script_tracking %}
    <script>
        // Initialize data layer
        window.dataLayer = window.dataLayer || [];

        // Push page-level data
        window.dataLayer.push({
            'pageType': '{{ page.pageType|default('other') }}',
            'salesChannelId': '{{ context.salesChannel.id }}',
            'salesChannelName': '{{ context.salesChannel.name }}',
            'currency': '{{ context.currency.isoCode }}',
            'language': '{{ context.salesChannel.language.locale.code }}',
            'country': '{{ context.salesChannel.country.iso|default('') }}',
            {% if context.customer %}
            'customerId': '{{ context.customer.id }}',
            'customerGroup': '{{ context.customer.group.translated.name }}',
            'customerType': 'customer',
            {% else %}
            'customerId': '',
            'customerGroup': 'Guest',
            'customerType': 'guest',
            {% endif %}
        });
    </script>

    {{ parent() }}
    {# GTM code here #}
{% endblock %}

Page-Specific Data Layers

Homepage Data Layer

{% block page_content %}
    {% if page.pageType == 'index' %}
        <script>
            window.dataLayer = window.dataLayer || [];
            window.dataLayer.push({
                'event': 'page_view',
                'pageType': 'home',
                'pagePath': '{{ app.request.pathInfo }}',
                'pageTitle': '{{ page.metaInformation.metaTitle|default('Home') }}'
            });
        </script>
    {% endif %}

    {{ parent() }}
{% endblock %}

Product Listing (Category) Data Layer

{% block page_product_listing %}
    {{ parent() }}

    <script>
        window.dataLayer = window.dataLayer || [];

        // Push category data
        window.dataLayer.push({
            'event': 'page_view',
            'pageType': 'category',
            'categoryId': '{{ page.category.id }}',
            'categoryName': '{{ page.category.translated.name|e('js') }}',
            'categoryPath': '{{ page.category.breadcrumb|join(' > ')|e('js') }}',
            'productCount': {{ page.listing.total }}
        });

        // Push product impressions
        {% if page.listing.elements %}
            window.dataLayer.push({
                'event': 'view_item_list',
                'ecommerce': {
                    'item_list_id': '{{ page.category.id }}',
                    'item_list_name': '{{ page.category.translated.name|e('js') }}',
                    'items': [
                        {% for product in page.listing.elements %}
                        {
                            'item_id': '{{ product.productNumber }}',
                            'item_name': '{{ product.translated.name|e('js') }}',
                            'item_brand': '{{ product.manufacturer.translated.name|default('')|e('js') }}',
                            'item_category': '{{ product.categories.first.translated.name|default('')|e('js') }}',
                            'price': {{ product.calculatedPrice.unitPrice }},
                            'quantity': 1,
                            'index': {{ loop.index0 }}
                        }{% if not loop.last %},{% endif %}
                        {% endfor %}
                    ]
                }
            });
        {% endif %}
    </script>
{% endblock %}

Product Detail Page Data Layer

{% block page_product_detail %}
    {{ parent() }}

    <script>
        window.dataLayer = window.dataLayer || [];

        {% set product = page.product %}

        // Push product detail data
        window.dataLayer.push({
            'event': 'page_view',
            'pageType': 'product',
            'productId': '{{ product.id }}',
            'productNumber': '{{ product.productNumber }}',
            'productName': '{{ product.translated.name|e('js') }}',
            'productPrice': {{ product.calculatedPrice.unitPrice }},
            'productCurrency': '{{ context.currency.isoCode }}',
            'productBrand': '{{ product.manufacturer.translated.name|default('')|e('js') }}',
            'productCategory': '{{ product.categories.first.translated.name|default('')|e('js') }}',
            'productStock': {{ product.availableStock }},
            'productAvailable': {{ product.available ? 'true' : 'false' }}
        });

        // Push view_item event
        window.dataLayer.push({
            'event': 'view_item',
            'ecommerce': {
                'currency': '{{ context.currency.isoCode }}',
                'value': {{ product.calculatedPrice.unitPrice }},
                'items': [{
                    'item_id': '{{ product.productNumber }}',
                    'item_name': '{{ product.translated.name|e('js') }}',
                    'item_brand': '{{ product.manufacturer.translated.name|default('')|e('js') }}',
                    'item_category': '{{ product.categories.first.translated.name|default('')|e('js') }}',
                    {% if product.options %}
                    'item_variant': '{{ product.options|map(o => o.translated.name)|join(', ')|e('js') }}',
                    {% endif %}
                    'price': {{ product.calculatedPrice.unitPrice }},
                    'quantity': 1
                }]
            }
        });

        // Store product data for add to cart event
        window.shopwareProduct = {
            id: '{{ product.id }}',
            productNumber: '{{ product.productNumber }}',
            name: '{{ product.translated.name|e('js') }}',
            price: {{ product.calculatedPrice.unitPrice }},
            currency: '{{ context.currency.isoCode }}',
            brand: '{{ product.manufacturer.translated.name|default('')|e('js') }}',
            category: '{{ product.categories.first.translated.name|default('')|e('js') }}'
        };
    </script>
{% endblock %}

Cart Page Data Layer

{% block page_checkout_cart %}
    {{ parent() }}

    <script>
        window.dataLayer = window.dataLayer || [];

        // Push cart page view
        window.dataLayer.push({
            'event': 'page_view',
            'pageType': 'cart',
            'cartTotal': {{ page.cart.price.totalPrice }},
            'cartItemCount': {{ page.cart.lineItems.count }},
            'cartCurrency': '{{ context.currency.isoCode }}'
        });

        {% if page.cart.lineItems.count > 0 %}
            // Push view_cart event
            window.dataLayer.push({
                'event': 'view_cart',
                'ecommerce': {
                    'currency': '{{ context.currency.isoCode }}',
                    'value': {{ page.cart.price.totalPrice }},
                    'items': [
                        {% for lineItem in page.cart.lineItems %}
                        {
                            'item_id': '{{ lineItem.referencedId }}',
                            'item_name': '{{ lineItem.label|e('js') }}',
                            'price': {{ lineItem.price.unitPrice }},
                            'quantity': {{ lineItem.quantity }}
                        }{% if not loop.last %},{% endif %}
                        {% endfor %}
                    ]
                }
            });

            // Store cart data for global access
            window.shopwareCart = {
                items: [
                    {% for lineItem in page.cart.lineItems %}
                    {
                        id: '{{ lineItem.referencedId }}',
                        name: '{{ lineItem.label|e('js') }}',
                        price: {{ lineItem.price.unitPrice }},
                        quantity: {{ lineItem.quantity }}
                    }{% if not loop.last %},{% endif %}
                    {% endfor %}
                ],
                total: {{ page.cart.price.totalPrice }},
                currency: '{{ context.currency.isoCode }}'
            };
        {% endif %}
    </script>
{% endblock %}

Checkout Page Data Layer

{% block page_checkout_confirm %}
    {{ parent() }}

    <script>
        window.dataLayer = window.dataLayer || [];

        // Push checkout page view
        window.dataLayer.push({
            'event': 'page_view',
            'pageType': 'checkout'
        });

        {% if page.cart.lineItems.count > 0 %}
            // Push begin_checkout event
            window.dataLayer.push({
                'event': 'begin_checkout',
                'ecommerce': {
                    'currency': '{{ context.currency.isoCode }}',
                    'value': {{ page.cart.price.totalPrice }},
                    'items': [
                        {% for lineItem in page.cart.lineItems %}
                        {
                            'item_id': '{{ lineItem.referencedId }}',
                            'item_name': '{{ lineItem.label|e('js') }}',
                            'price': {{ lineItem.price.unitPrice }},
                            'quantity': {{ lineItem.quantity }}
                        }{% if not loop.last %},{% endif %}
                        {% endfor %}
                    ]
                }
            });
        {% endif %}
    </script>
{% endblock %}

Order Confirmation Data Layer

{% block page_checkout_finish %}
    {{ parent() }}

    <script>
        window.dataLayer = window.dataLayer || [];

        {% set order = page.order %}
        {% if order %}
            // Push order confirmation page view
            window.dataLayer.push({
                'event': 'page_view',
                'pageType': 'confirmation',
                'orderId': '{{ order.id }}',
                'orderNumber': '{{ order.orderNumber }}'
            });

            // Push purchase event
            window.dataLayer.push({
                'event': 'purchase',
                'ecommerce': {
                    'transaction_id': '{{ order.orderNumber }}',
                    'affiliation': '{{ context.salesChannel.name }}',
                    'value': {{ order.amountTotal }},
                    'tax': {{ order.amountTotal - order.amountNet }},
                    'shipping': {{ order.shippingCosts.totalPrice }},
                    'currency': '{{ order.currency.isoCode }}',
                    {% if order.lineItems|filter(item => item.type == 'promotion')|length > 0 %}
                    'coupon': '{{ order.lineItems|filter(item => item.type == 'promotion')|first.payload.code }}',
                    {% endif %}
                    'items': [
                        {% for lineItem in order.lineItems %}
                        {% if lineItem.type == 'product' %}
                        {
                            'item_id': '{{ lineItem.payload.productNumber|default(lineItem.id) }}',
                            'item_name': '{{ lineItem.label|e('js') }}',
                            'price': {{ lineItem.unitPrice }},
                            'quantity': {{ lineItem.quantity }}
                        }{% if not loop.last %},{% endif %}
                        {% endif %}
                        {% endfor %}
                    ]
                }
            });
        {% endif %}
    </script>
{% endblock %}

Event-Based Data Layer Pushes

Add to Cart Event

// Listen for Shopware add to cart events
document.addEventListener('DOMContentLoaded', function() {
    // For standard add to cart
    const buyForms = document.querySelectorAll('.product-detail-buy');

    buyForms.forEach(function(form) {
        form.addEventListener('submit', function(e) {
            const quantity = parseInt(this.querySelector('[name="quantity"]')?.value || 1);

            if (window.shopwareProduct) {
                window.dataLayer = window.dataLayer || [];
                window.dataLayer.push({
                    'event': 'add_to_cart',
                    'ecommerce': {
                        'currency': window.shopwareProduct.currency,
                        'value': window.shopwareProduct.price * quantity,
                        'items': [{
                            'item_id': window.shopwareProduct.productNumber,
                            'item_name': window.shopwareProduct.name,
                            'item_brand': window.shopwareProduct.brand,
                            'item_category': window.shopwareProduct.category,
                            'price': window.shopwareProduct.price,
                            'quantity': quantity
                        }]
                    }
                });
            }
        });
    });
});

Remove from Cart Event

// Track cart item removals
document.addEventListener('click', function(e) {
    const removeButton = e.target.closest('[data-cart-item-remove]');

    if (removeButton) {
        const lineItem = removeButton.closest('[data-cart-item]');
        const lineItemId = lineItem?.dataset.cartItemId;

        // Find item in cart data
        if (window.shopwareCart && window.shopwareCart.items) {
            const item = window.shopwareCart.items.find(i => i.id === lineItemId);

            if (item) {
                window.dataLayer = window.dataLayer || [];
                window.dataLayer.push({
                    'event': 'remove_from_cart',
                    'ecommerce': {
                        'currency': window.shopwareCart.currency,
                        'value': item.price * item.quantity,
                        'items': [{
                            'item_id': item.id,
                            'item_name': item.name,
                            'price': item.price,
                            'quantity': item.quantity
                        }]
                    }
                });
            }
        }
    }
}, false);

Search Event

// Track search queries
document.addEventListener('DOMContentLoaded', function() {
    const searchForm = document.querySelector('.header-search-form');

    if (searchForm) {
        searchForm.addEventListener('submit', function(e) {
            const searchInput = searchForm.querySelector('input[name="search"]');
            const searchTerm = searchInput ? searchInput.value : '';

            if (searchTerm) {
                window.dataLayer = window.dataLayer || [];
                window.dataLayer.push({
                    'event': 'search',
                    'search_term': searchTerm
                });
            }
        });
    }
});

Creating GTM Variables from Data Layer

In Google Tag Manager:

Go to Variables → New
Variable Configuration → Data Layer Variable
Configure Variable:
- Name: Product Name
- Data Layer Variable Name: productName
- Default Value: (not set)

Common GTM Variables for Shopware

Create these Data Layer Variables in GTM:

Variable Name	Data Layer Variable Name	Type
Page Type	`pageType`	Data Layer Variable
Product ID	`productId`	Data Layer Variable
Product Name	`productName`	Data Layer Variable
Product Price	`productPrice`	Data Layer Variable
Currency Code	`currency`	Data Layer Variable
Customer ID	`customerId`	Data Layer Variable
Customer Group	`customerGroup`	Data Layer Variable
Sales Channel ID	`salesChannelId`	Data Layer Variable
Order Number	`orderNumber`	Data Layer Variable
Cart Total	`cartTotal`	Data Layer Variable

Using Data Layer Variables in GTM Tags

Example: GA4 Configuration Tag

Tag Configuration:

Tag Type: Google Analytics: GA4 Configuration
Measurement ID: G-XXXXXXXXXX
Configuration Settings:
- Fields to Set:
  - currency: \{\{Currency Code\}\}
  - user_id: \{\{Customer ID\}\}
- User Properties:
  - customer_group: \{\{Customer Group\}\}
  - sales_channel: \{\{Sales Channel ID\}\}

Example: Event Tag with Data Layer

Tag Configuration:

Tag Type: Google Analytics: GA4 Event
Event Name: view_product
Event Parameters:
- product_id: \{\{Product ID\}\}
- product_name: \{\{Product Name\}\}
- value: \{\{Product Price\}\}
- currency: \{\{Currency Code\}\}

Triggering:

Trigger Type: Page View
Some Page Views
Page Type equals product

Debugging Data Layer

Browser Console

Check data layer contents:

// View entire data layer
console.table(window.dataLayer);

// View latest push
console.log(window.dataLayer[window.dataLayer.length - 1]);

// Monitor all pushes
(function() {
    const originalPush = window.dataLayer.push;
    window.dataLayer.push = function() {
        console.log('dataLayer.push:', arguments[0]);
        return originalPush.apply(window.dataLayer, arguments);
    };
})();

GTM Preview Mode

Open GTM → Preview
Connect to your Shopware store
Navigate pages
View Data Layer tab in Tag Assistant
Check all values populate correctly

Common Issues

Data layer is undefined:

{# Always initialize before use #}
<script>
    window.dataLayer = window.dataLayer || [];
</script>

Values are empty:

Check Twig variables are available
Verify context data exists
Add fallback values:

'productName': '{{ product.translated.name|default('Unknown')|e('js') }}'

JavaScript errors:

Escape special characters in strings
Use |e('js') filter in Twig
Check for missing commas in JSON

Advanced Data Layer Patterns

// After successful login
window.dataLayer = window.dataLayer || [];
window.dataLayer.push({
    'event': 'login',
    'method': 'email',
    'userId': '{{ customer.id }}',
    'customerGroup': '{{ customer.group.translated.name }}'
});

// After newsletter form submission
window.dataLayer.push({
    'event': 'newsletter_signup',
    'location': 'footer',
    'email_hash': hashEmail(email) // Hash email for privacy
});

Product Click

// When product is clicked in listing
window.dataLayer.push({
    'event': 'select_item',
    'ecommerce': {
        'item_list_id': 'category_123',
        'item_list_name': 'Running Shoes',
        'items': [{
            'item_id': 'SKU123',
            'item_name': 'Product Name',
            'index': 0
        }]
    }
});

Best Practices

1. Always Initialize Data Layer

<script>
    window.dataLayer = window.dataLayer || [];
</script>

2. Push Events After Data

// Bad: Event might fire before data is available
window.dataLayer.push({ 'event': 'purchase' });
window.dataLayer.push({ 'transactionId': '12345' });

// Good: Data before event
window.dataLayer.push({
    'transactionId': '12345',
    'event': 'purchase'
});

3. Escape User-Generated Content

{# Always escape to prevent XSS #}
'productName': '{{ product.translated.name|e('js') }}'

4. Use Consistent Naming

Use camelCase or snake_case consistently
Match GA4 parameter names when possible
Document custom parameters

5. Don't Push Sensitive Data

Never push:

Full email addresses (hash if needed)
Passwords
Credit card numbers
Personal identification numbers

Hash sensitive data:

function hashEmail(email) {
    // Use a hashing library
    return CryptoJS.SHA256(email.toLowerCase()).toString();
}

Next Steps

GA4 Ecommerce Tracking - Use data layer for GA4
Troubleshoot Tracking - Debug data layer issues
GTM Setup - Install GTM if not already done

For general GTM and data layer concepts, see Google Tag Manager Documentation.