Introduced a custom ExponentialNumberType for parameter values

This type shows small values in exponential notation instead of rounding it to zero.

src/Form/ParameterType.php

@@ -53,6 +53,7 @@ use App\Entity\Parameters\PartParameter;
 use App\Entity\Parameters\StorageLocationParameter;
 use App\Entity\Parameters\SupplierParameter;
 use App\Entity\Parts\MeasurementUnit;
+use App\Form\Type\ExponentialNumberType;
 use Symfony\Component\Form\AbstractType;
 use Symfony\Component\Form\Extension\Core\Type\NumberType;
 use Symfony\Component\Form\Extension\Core\Type\TextType;
@@ -93,7 +94,7 @@ class ParameterType extends AbstractType
             ],
         ]);
 
-        $builder->add('value_max', NumberType::class, [
+        $builder->add('value_max', ExponentialNumberType::class, [
             'label' => false,
             'required' => false,
             'html5' => true,
@@ -104,7 +105,7 @@ class ParameterType extends AbstractType
                 'style' => 'max-width: 12ch;',
             ],
         ]);
-        $builder->add('value_min', NumberType::class, [
+        $builder->add('value_min', ExponentialNumberType::class, [
             'label' => false,
             'required' => false,
             'html5' => true,
@@ -115,7 +116,7 @@ class ParameterType extends AbstractType
                 'style' => 'max-width: 12ch;',
             ],
         ]);
-        $builder->add('value_typical', NumberType::class, [
+        $builder->add('value_typical', ExponentialNumberType::class, [
             'label' => false,
             'required' => false,
             'html5' => true,

src/Form/Type/ExponentialNumberType.php

@@ -0,0 +1,52 @@
+<?php
+/*
+ * This file is part of Part-DB (https://github.com/Part-DB/Part-DB-symfony).
+ *
+ *  Copyright (C) 2019 - 2024 Jan Böhmer (https://github.com/jbtronics)
+ *
+ *  This program is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU Affero General Public License as published
+ *  by the Free Software Foundation, either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU Affero General Public License for more details.
+ *
+ *  You should have received a copy of the GNU Affero General Public License
+ *  along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+declare(strict_types=1);
+
+
+namespace App\Form\Type;
+
+use App\Form\Type\Helper\ExponentialNumberTransformer;
+use Symfony\Component\Form\AbstractType;
+use Symfony\Component\Form\Extension\Core\Type\NumberType;
+use Symfony\Component\Form\FormBuilderInterface;
+
+/**
+ * Similar to the NumberType, but formats small values in scienfitic notation instead of rounding it to 0, like NumberType
+ */
+class ExponentialNumberType extends AbstractType
+{
+    public function getParent(): string
+    {
+        return NumberType::class;
+    }
+
+    public function buildForm(FormBuilderInterface $builder, array $options)
+    {
+        $builder->resetViewTransformers();
+
+        $builder->addViewTransformer(new ExponentialNumberTransformer(
+            $options['scale'],
+            $options['grouping'],
+            $options['rounding_mode'],
+            $options['html5'] ? 'en' : null
+        ));
+    }
+}

src/Form/Type/Helper/ExponentialNumberTransformer.php

@@ -0,0 +1,96 @@
+<?php
+/*
+ * This file is part of Part-DB (https://github.com/Part-DB/Part-DB-symfony).
+ *
+ *  Copyright (C) 2019 - 2024 Jan Böhmer (https://github.com/jbtronics)
+ *
+ *  This program is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU Affero General Public License as published
+ *  by the Free Software Foundation, either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU Affero General Public License for more details.
+ *
+ *  You should have received a copy of the GNU Affero General Public License
+ *  along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+declare(strict_types=1);
+
+
+namespace App\Form\Type\Helper;
+
+use App\Form\Fixes\FixedNumberToLocalizedStringTransformer;
+use Symfony\Component\Form\Exception\TransformationFailedException;
+
+/**
+ * This transformer formats small values in scienfitic notation instead of rounding it to 0, like the default
+ * NumberFormatter.
+ */
+class ExponentialNumberTransformer extends FixedNumberToLocalizedStringTransformer
+{
+    public function __construct(
+        protected ?int $scale = null,
+        ?bool $grouping = false,
+        ?int $roundingMode = \NumberFormatter::ROUND_HALFUP,
+        protected ?string $locale = null
+    ) {
+        parent::__construct($scale, $grouping, $roundingMode, $locale);
+    }
+
+    /**
+     * Transforms a number type into localized number.
+     *
+     * @param int|float|null $value Number value
+     *
+     * @throws TransformationFailedException if the given value is not numeric
+     *                                       or if the value cannot be transformed
+     */
+    public function transform(mixed $value): string
+    {
+        if (null === $value) {
+            return '';
+        }
+
+        if (!is_numeric($value)) {
+            throw new TransformationFailedException('Expected a numeric.');
+        }
+
+        //If the value is too small, the number formatter would return 0, therfore use exponential notation for small numbers
+        if (abs($value) < 1e-3) {
+            $formatter = $this->getScientificNumberFormatter();
+        } else {
+            $formatter = $this->getNumberFormatter();
+        }
+
+
+
+        $value = $formatter->format($value);
+
+        if (intl_is_failure($formatter->getErrorCode())) {
+            throw new TransformationFailedException($formatter->getErrorMessage());
+        }
+
+        // Convert non-breaking and narrow non-breaking spaces to normal ones
+        $value = str_replace(["\xc2\xa0", "\xe2\x80\xaf"], ' ', $value);
+
+        return $value;
+    }
+
+    protected function getScientificNumberFormatter(): \NumberFormatter
+    {
+        $formatter = new \NumberFormatter($this->locale ?? \Locale::getDefault(), \NumberFormatter::SCIENTIFIC);
+
+        if (null !== $this->scale) {
+            $formatter->setAttribute(\NumberFormatter::FRACTION_DIGITS, $this->scale);
+            $formatter->setAttribute(\NumberFormatter::ROUNDING_MODE, $this->roundingMode);
+        }
+
+        $formatter->setAttribute(\NumberFormatter::GROUPING_USED, (int) $this->grouping);
+
+        return $formatter;
+    }
+}