FloatItem.php

<?php

namespace Drupal\Core\Field\Plugin\Field\FieldType;

use Drupal\Core\Field\FieldDefinitionInterface;
use Drupal\Core\Field\FieldStorageDefinitionInterface;
use Drupal\Core\Form\FormStateInterface;
use Drupal\Core\TypedData\DataDefinition;

/**
 * Defines the 'float' field type.
 *
 * @FieldType(
 *   id = "float",
 *   label = @Translation("Number (float)"),
 *   description = @Translation("This field stores a number in the database in a floating point format."),
 *   category = @Translation("Number"),
 *   default_widget = "number",
 *   default_formatter = "number_decimal"
 * )
 */
class FloatItem extends NumericItemBase {
    
    /**
     * {@inheritdoc}
     */
    public static function propertyDefinitions(FieldStorageDefinitionInterface $field_definition) {
        $properties['value'] = DataDefinition::create('float')->setLabel(t('Float'))
            ->setRequired(TRUE);
        return $properties;
    }
    
    /**
     * {@inheritdoc}
     */
    public static function schema(FieldStorageDefinitionInterface $field_definition) {
        return [
            'columns' => [
                'value' => [
                    'type' => 'float',
                ],
            ],
        ];
    }
    
    /**
     * {@inheritdoc}
     */
    public function fieldSettingsForm(array $form, FormStateInterface $form_state) {
        $element = parent::fieldSettingsForm($form, $form_state);
        $element['min']['#step'] = 'any';
        $element['max']['#step'] = 'any';
        return $element;
    }
    
    /**
     * {@inheritdoc}
     */
    public static function generateSampleValue(FieldDefinitionInterface $field_definition) {
        $settings = $field_definition->getSettings();
        $precision = rand(10, 32);
        $scale = rand(0, 2);
        $max = is_numeric($settings['max']) ? $settings['max'] : pow(10, $precision - $scale) - 1;
        $min = is_numeric($settings['min']) ? $settings['min'] : -pow(10, $precision - $scale) + 1;
        // @see "Example #1 Calculate a random floating-point number" in
        // http://php.net/manual/function.mt-getrandmax.php
        $random_decimal = $min + mt_rand() / mt_getrandmax() * ($max - $min);
        $values['value'] = self::truncateDecimal($random_decimal, $scale);
        return $values;
    }

}