Product Configurator in Odoo 19:
Dynamic Attributes, Variants & Custom Options

# In the Odoo shell, check how many variants a template would generate
template = env['product.template'].browse(42)
lines = template.attribute_line_ids

# Calculate the Cartesian product
from functools import reduce
from operator import mul
total = reduce(mul, [len(line.value_ids) for line in lines], 1)
print(f"Template '{template.name}' would generate {total} variants")

# If total > 1000, you almost certainly want 'dynamic' mode
# Check current actual variant count
print(f"Current variants: {template.product_variant_count}")

# List attributes contributing most to the explosion
for line in lines.sorted(key=lambda l: len(l.value_ids), reverse=True):
    print(f"  {line.attribute_id.name}: {len(line.value_ids)} values")

<!-- 'always' = Instantly | 'dynamic' = Dynamically | 'no_variant' = Never -->
<record id="attr_processor" model="product.attribute">
    <field name="name">Processor</field>
    <field name="display_type">radio</field>
    <field name="create_variant">dynamic</field>
</record>

<record id="attr_engraving" model="product.attribute">
    <field name="name">Engraving Text</field>
    <field name="display_type">radio</field>
    <field name="create_variant">no_variant</field>
</record>

<!-- Prevent "Matte" finish with "Red" color on the Premium T-Shirt -->
<record id="exclusion_matte_red" model="product.template.attribute.exclusion">
    <field name="product_tmpl_id" ref="product_tshirt"/>
    <field name="product_template_attribute_value_id"
           ref="ptav_tshirt_matte"/>
    <field name="value_ids" eval="[
        Command.set([ref('ptav_tshirt_red')])
    ]"/>
</record>

<!-- Multiple exclusions: "Organic" fabric excludes both "Neon Green" and "Neon Pink" -->
<record id="exclusion_organic_neon" model="product.template.attribute.exclusion">
    <field name="product_tmpl_id" ref="product_tshirt"/>
    <field name="product_template_attribute_value_id"
           ref="ptav_tshirt_organic"/>
    <field name="value_ids" eval="[
        Command.set([
            ref('ptav_tshirt_neon_green'),
            ref('ptav_tshirt_neon_pink'),
        ])
    ]"/>
</record>

<!-- On the Premium T-Shirt, suggest these optional add-ons -->
<record id="product_tshirt" model="product.template">
    <field name="optional_product_ids" eval="[
        Command.set([
            ref('product_matching_cap'),
            ref('product_gift_wrapping'),
            ref('product_tshirt_care_kit'),
        ])
    ]"/>
</record>

<!-- Optional products can themselves be configurable -->
<!-- The "Matching Cap" has its own Color attribute -->
<!-- The configurator pre-selects the same color as the parent product -->

# Check which combinations are excluded for a product template
template = env['product.template'].browse(42)

exclusions = env['product.template.attribute.exclusion'].search([
    ('product_tmpl_id', '=', template.id),
])

for exc in exclusions:
    source = exc.product_template_attribute_value_id
    targets = exc.value_ids
    print(f"  If '{source.name}' is selected, exclude: "
          f"{', '.join(targets.mapped('name'))}")

# Validate a combination before creating a variant
ptav_ids = env['product.template.attribute.value'].browse([101, 205, 308])
is_valid = template._is_combination_possible(ptav_ids)
print(f"Combination valid: {is_valid}")

<!-- Extend the product page to show a size guide below the Size attribute -->
<template id="product_size_guide"
          inherit_id="website_sale.product"
          name="Size Guide Link">
    <xpath expr="//div[hasclass('js_product')]//table[hasclass('table')]"
           position="after">
        <t t-if="any(
            line.attribute_id.name == 'Size'
            for line in product.attribute_line_ids
        )">
            <a href="#size-guide-modal"
               class="btn btn-link btn-sm mt-1"
               data-bs-toggle="modal">
                View Size Guide
            </a>
        </t>
    </xpath>
</template>

<!-- Show stock per variant on the product page -->
<template id="product_variant_stock"
          inherit_id="website_sale.product"
          name="Variant Stock Display">
    <xpath expr="//div[@id='product_details']//a[@id='add_to_cart']"
           position="before">
        <div class="variant-stock-info mb-2"
             t-if="product_variant and product_variant.sudo().free_qty > 0">
            <span class="badge bg-success">
                <t t-out="int(product_variant.sudo().free_qty)"/> in stock
            </span>
        </div>
        <div class="variant-stock-info mb-2"
             t-elif="product_variant">
            <span class="badge bg-warning">Made to order</span>
        </div>
    </xpath>
</template>

import base64
from pathlib import Path

template = env['product.template'].browse(42)

# Map variant attribute values to image files
image_map = {
    'Red': '/opt/images/tshirt_red.jpg',
    'Blue': '/opt/images/tshirt_blue.jpg',
    'Black': '/opt/images/tshirt_black.jpg',
}

for variant in template.product_variant_ids:
    # Get the color value for this variant
    color_val = variant.product_template_variant_value_ids.filtered(
        lambda v: v.attribute_id.name == 'Color'
    )
    if color_val and color_val.name in image_map:
        img_path = Path(image_map[color_val.name])
        if img_path.exists():
            variant.image_1920 = base64.b64encode(img_path.read_bytes())
            print(f"  Set image for {variant.display_name}")

env.cr.commit()