README

Physical dimensions value objects and Doctrine integration for Symfony — designed for archival, museum, and document workflows.

Store everything as integer millimeters. Display in any unit. Query with real columns.

The problem

Museum objects, archival items, and documents need physical dimensions. The naive approach — storing floats in a JSON blob or ad-hoc width_cm/height_in columns — breaks querying, causes unit confusion, and makes display logic sprawl across templates.

The solution

use Survos\DimensionsBundle\ValueObject\Dimensions;
use Doctrine\ORM\Mapping as ORM;

#[ORM\Entity]
class ArchivalItem
{
    #[ORM\Embedded(class: Dimensions::class, columnPrefix: false)]
    private ?Dimensions $dimensions = null;
}

This creates three nullable integer columns (width_mm, height_mm, depth_mm) — real columns, real indexes, real range queries. Display formatting, unit conversion, and parsing happen in PHP.

Installation

composer require survos/dimensions-bundle

The custom dimension DBAL type and Twig filters are registered automatically.

Core value objects

Unit enum

use Survos\DimensionsBundle\ValueObject\Unit;

Unit::CM->toMillimeters(); // 10.0
Unit::IN->toMillimeters(); // 25.4
Unit::FT->toMillimeters(); // 304.8

Dimension (single axis)

use Survos\DimensionsBundle\ValueObject\Dimension;

$d = Dimension::fromInches(8.5);    // Dimension(216)
$d = Dimension::from(21.6, Unit::CM); // Dimension(216)

// PHP 8.4 property hooks — computed, no backing store
$d->cm;     // 21.6
$d->inches; // 8.503...
$d->feet;   // 0.708...
$d->meters; // 0.216

$d->to(Unit::IN); // float
(string) $d;      // "216 mm"

Dimensions (composite W × H × D)

use Survos\DimensionsBundle\ValueObject\Dimensions;

$dims = new Dimensions(widthMm: 216, heightMm: 279);      // Letter paper
$dims = new Dimensions(widthMm: 216, heightMm: 279, depthMm: 25); // With depth

// PHP 8.4 property hooks
$dims->width;   // ?Dimension(216)
$dims->height;  // ?Dimension(279)
$dims->depth;   // null (or Dimension)
$dims->area;    // ?int — mm²
$dims->volume;  // ?int — mm³
$dims->is2D;    // true when depth is null
$dims->isEmpty; // true when all axes are null

$dims->isFlat(5);           // true when depth < 5 mm (e.g., a sheet of paper)
$dims->format(Unit::CM);    // "21.6 × 27.9 cm"
(string) $dims;             // "21.6 × 27.9 cm" (locale-independent)

Doctrine integration

Option A: Embeddable (recommended)

#[ORM\Embedded(class: Dimensions::class, columnPrefix: false)]
private ?Dimensions $dimensions = null;

Generates columns: width_mm INTEGER, height_mm INTEGER, depth_mm INTEGER (all nullable).

Use columnPrefix: 'physical_' to namespace the columns when an entity has multiple dimension sets (e.g., physical_width_mm, mount_width_mm).

Option B: Custom type for a single axis

use Survos\DimensionsBundle\Doctrine\DimensionType;

#[ORM\Column(type: DimensionType::NAME, nullable: true)]
private ?Dimension $thickness = null;

Stored as INTEGER, hydrated to a Dimension value object.

Parsing

use Survos\DimensionsBundle\Parser\DimensionParser;

$parser = new DimensionParser();

$parser->parseDimension('8.5 in');          // Dimension(216)
$parser->parseDimension('4ft 2in');         // Dimension(1270)
$parser->parseDimension('216');             // Dimension(216) — assumes default unit (mm)

$parser->parseDimensions('8.5 × 11 in');    // Dimensions(216, 279, null)
$parser->parseDimensions('21.6 x 27.9 cm'); // Dimensions(216, 279, null)
$parser->parseDimensions('10 × 12 × 3 in'); // Dimensions(254, 305, 76)

Accepts × (Unicode), x, X as separators. Whitespace tolerant. Default unit is configurable.

Twig filters

{# Composite dimensions #}
{{ item.dimensions|dim }}                  {# "21.6 × 27.9 cm" #}
{{ item.dimensions|dim('in', 2) }}         {# "8.50 × 11.00 in" #}
{{ item.dimensions|dim_both }}             {# "21.6 × 27.9 cm (8.5 × 11.0 in)" #}

{# Single dimension #}
{{ item.thickness|dim_value }}             {# "0.3 mm" #}
{{ item.thickness|dim_value('mm', 0) }}    {# "0" #}

{# Area & volume #}
{{ item.dimensions|dim_area('cm') }}       {# "602.6 cm²" #}
{{ item.dimensions|dim_volume('cm') }}     {# "1807.7 cm³" #}

All filters are null-safe — an empty or null Dimensions returns ''.

Form types

use Survos\DimensionsBundle\Form\DimensionsType;
use Survos\DimensionsBundle\ValueObject\Unit;

$builder->add('dimensions', DimensionsType::class, [
    'display_unit' => 'cm',    // user sees cm; stored as int mm
    'allow_depth'  => true,
    'required'     => false,
]);

For a single axis (e.g., thickness):

use Survos\DimensionsBundle\Form\DimensionType;

$builder->add('thickness', DimensionType::class, [
    'display_unit' => 'mm',
]);

Serializer / API Platform

DimensionsNormalizer outputs width/height/depth in mm plus pre-computed display strings:

{
  "width_mm": 216,
  "height_mm": 279,
  "depth_mm": null,
  "display": {
    "cm": "21.6 × 27.9 cm",
    "in": "8.5 × 11.0 in",
    "mm": "216 × 279 mm"
  }
}

Denormalization accepts either int-mm keys or {value, unit} objects:

{ "width": { "value": 8.5, "unit": "in" }, "height": { "value": 11, "unit": "in" } }

Configuration

# config/packages/survos_dimensions.yaml
survos_dimensions:
    default_display_unit: cm    # mm | cm | m | in | ft
    default_input_unit:   mm
    default_precision:    1
    show_both_units:      false  # when true, formatters output "21.6 cm (8.5 in)"
    flat_threshold_mm:    5

Per-user display unit

Implement DimensionPreferenceInterface and register it as a service to override the display unit per user, institution, or session:

use Survos\DimensionsBundle\Service\DimensionPreferenceInterface;

class UserDimensionPreference implements DimensionPreferenceInterface
{
    public function __construct(private readonly Security $security) {}

    public function getPreferredDisplayUnit(): ?string
    {
        return $this->security->getUser()?->getPreferredUnit(); // 'in' for US institutions
    }
}

Status

PHP 8.4+ · Symfony 7/8 · Doctrine ORM 3