Floats must not be stored as locale dependent

Floats are currently stored formatted per the locale setting. This leads to different values being written whether the locale uses "." or "," for the decimal point for instance. This poses a problem as floats must be stored using "." as the decimal point to be valid.
This commit ensures that the floats are stored correctly by forcing the formatting of the value.

src/Spout/Common/Helper/StringHelper.php

@@ -13,12 +13,20 @@ class StringHelper
     /** @var bool Whether the mbstring extension is loaded */
     protected $hasMbstringSupport;
 
+    /** @var bool Whether the code is running with PHP7 or older versions */
+    private $isRunningPhp7OrOlder;
+
+    /** @var array Locale info, used for number formatting */
+    private $localeInfo;
+
     /**
      *
      */
     public function __construct()
     {
         $this->hasMbstringSupport = \extension_loaded('mbstring');
+        $this->isRunningPhp7OrOlder = \version_compare(PHP_VERSION, '8.0.0') < 0;
+        $this->localeInfo = \localeconv();
     }
 
     /**
@@ -68,4 +76,30 @@ public function getCharLastOccurrencePosition($char, $string)
 
         return ($position !== false) ? $position : -1;
     }
+
+    /**
+     * Formats a numeric value (int or float) in a way that's compatible with the expected spreadsheet format.
+     *
+     * Formatting of float values is locale dependent in PHP < 8.
+     * Thousands separators and decimal points vary from locale to locale (en_US: 12.34 vs pl_PL: 12,34).
+     * However, float values must be formatted with no thousands separator and a "." as decimal point
+     * to work properly. This method can be used to convert the value to the correct format before storing it.
+     *
+     * @see https://wiki.php.net/rfc/locale_independent_float_to_string for the changed behavior in PHP8.
+     *
+     * @param int|float $numericValue
+     * @return string
+     */
+    public function formatNumericValue($numericValue)
+    {
+        if ($this->isRunningPhp7OrOlder && is_float($numericValue)) {
+            return str_replace(
+                [$this->localeInfo['thousands_sep'], $this->localeInfo['decimal_point']],
+                ['', '.'],
+                $numericValue
+            );
+        }
+
+        return $numericValue;
+    }
 }

src/Spout/Writer/ODS/Manager/WorksheetManager.php

@@ -231,8 +231,9 @@ private function getCellXML(Cell $cell, $styleIndex, $numTimesValueRepeated)
             $data .= '<text:p>' . $cell->getValue() . '</text:p>';
             $data .= '</table:table-cell>';
         } elseif ($cell->isNumeric()) {
-            $data .= ' office:value-type="float" calcext:value-type="float" office:value="' . $cell->getValue() . '">';
-            $data .= '<text:p>' . $cell->getValue() . '</text:p>';
+            $cellValue = $this->stringHelper->formatNumericValue($cell->getValue());
+            $data .= ' office:value-type="float" calcext:value-type="float" office:value="' . $cellValue . '">';
+            $data .= '<text:p>' . $cellValue . '</text:p>';
             $data .= '</table:table-cell>';
         } elseif ($cell->isError() && is_string($cell->getValueEvenIfError())) {
             // only writes the error value if it's a string

src/Spout/Writer/XLSX/Manager/WorksheetManager.php

@@ -240,7 +240,7 @@ private function getCellXML($rowIndexOneBased, $columnIndexZeroBased, Cell $cell
         } elseif ($cell->isBoolean()) {
             $cellXML .= ' t="b"><v>' . (int) ($cell->getValue()) . '</v></c>';
         } elseif ($cell->isNumeric()) {
-            $cellXML .= '><v>' . $cell->getValue() . '</v></c>';
+            $cellXML .= '><v>' . $this->stringHelper->formatNumericValue($cell->getValue()) . '</v></c>';
         } elseif ($cell->isError() && is_string($cell->getValueEvenIfError())) {
             // only writes the error value if it's a string
             $cellXML .= ' t="e"><v>' . $cell->getValueEvenIfError() . '</v></c>';

tests/Spout/Writer/ODS/WriterTest.php

@@ -279,6 +279,52 @@ public function testAddRowShouldSupportMultipleTypesOfData()
         $this->assertValueWasWrittenToSheet($fileName, 1, 10.2);
     }
 
+    /**
+     * @return void
+     */
+    public function testAddRowShouldSupportFloatValuesInDifferentLocale()
+    {
+        $previousLocale = \setlocale(LC_ALL, 0);
+
+        try {
+            // Pick a supported locale whose decimal point is a comma.
+            // Installed locales differ from one system to another, so we can't pick
+            // a given locale.
+            $supportedLocales = explode("\n", shell_exec('locale -a'));
+            foreach ($supportedLocales as $supportedLocale) {
+                \setlocale(LC_ALL, $supportedLocale);
+                if (\localeconv()['decimal_point'] === ',') {
+                    break;
+                }
+            }
+            $this->assertEquals(',', \localeconv()['decimal_point']);
+
+            $cellValue = 1234.5;
+            var_dump("Cell value before: " . $cellValue);
+            $cellValue = str_replace(
+                [\localeconv()['thousands_sep'], \localeconv()['decimal_point']],
+                ['', '.'],
+                $cellValue
+            );
+            var_dump("Cell value after: " . $cellValue);
+            var_dump("Thousands sep: " . \localeconv()['thousands_sep']);
+            var_dump("Decimal point: " . \localeconv()['decimal_point']);
+
+            $fileName = 'test_add_row_should_support_float_values_in_different_locale.xlsx';
+            $dataRows = $this->createRowsFromValues([
+                [1234.5],
+            ]);
+
+            $this->writeToODSFile($dataRows, $fileName);
+
+            $this->assertValueWasNotWrittenToSheet($fileName, 1, "1234,5");
+            $this->assertValueWasWrittenToSheet($fileName, 1, "1234.5");
+        } finally {
+            // reset locale
+            \setlocale(LC_ALL, $previousLocale);
+        }
+    }
+
     /**
      * @return array
      */

tests/Spout/Writer/XLSX/WriterTest.php

@@ -393,6 +393,52 @@ public function testAddRowShouldSupportCellInError()
         $this->assertInlineDataWasWrittenToSheet($fileName, 1, 't="e"><v>#DIV/0</v>');
     }
 
+    /**
+     * @return void
+     */
+    public function testAddRowShouldSupportFloatValuesInDifferentLocale()
+    {
+        $previousLocale = \setlocale(LC_ALL, 0);
+        $valueToWrite = 1234.5; // needs to be defined before changing the locale as PHP8 would expect 1234,5
+
+        try {
+            // Pick a supported locale whose decimal point is a comma.
+            // Installed locales differ from one system to another, so we can't pick
+            // a given locale.
+            $supportedLocales = explode("\n", shell_exec('locale -a'));
+            foreach ($supportedLocales as $supportedLocale) {
+                \setlocale(LC_ALL, $supportedLocale);
+                if (\localeconv()['decimal_point'] === ',') {
+                    break;
+                }
+            }
+            $this->assertEquals(',', \localeconv()['decimal_point']);
+
+            var_dump("Cell value before: " . $valueToWrite);
+            $cellValue = str_replace(
+                [\localeconv()['thousands_sep'], \localeconv()['decimal_point']],
+                ['', '.'],
+                $valueToWrite
+            );
+            var_dump("Cell value after: " . $cellValue);
+            var_dump("Thousands sep: " . \localeconv()['thousands_sep']);
+            var_dump("Decimal point: " . \localeconv()['decimal_point']);
+
+            $fileName = 'test_add_row_should_support_float_values_in_different_locale.xlsx';
+            $dataRows = $this->createRowsFromValues([
+                [$valueToWrite],
+            ]);
+
+            $this->writeToXLSXFile($dataRows, $fileName, $shouldUseInlineStrings = false);
+
+            $this->assertInlineDataWasNotWrittenToSheet($fileName, 1, "1234,5");
+            $this->assertInlineDataWasWrittenToSheet($fileName, 1, "1234.5");
+        } finally {
+            // reset locale
+            \setlocale(LC_ALL, $previousLocale);
+        }
+    }
+
     /**
      * @return void
      */