Fixed handling of inline strings in XLSX (#2569)

* Fixed handling of inline strings

* Added an example for the "inline string" datatype for which the generated XML was fixed in the previous commit.

* Handle inline strings exactly the same way as regular strings in the XLS writer, because this is only relevant in the XLSX format.

samples/Basic/02_Types.php

@@ -1,5 +1,6 @@
 <?php
 
+use PhpOffice\PhpSpreadsheet\Cell\DataType;
 use PhpOffice\PhpSpreadsheet\RichText\RichText;
 use PhpOffice\PhpSpreadsheet\Shared\Date;
 use PhpOffice\PhpSpreadsheet\Spreadsheet;
@@ -144,6 +145,11 @@ $spreadsheet->getActiveSheet()
 $spreadsheet->getActiveSheet()
     ->setCellValue('C18', '=HYPERLINK("mailto:abc@def.com","abc@def.com")');
 
+$spreadsheet->getActiveSheet()
+    ->setCellValue('A20', 'String')
+    ->setCellValue('B20', 'inline')
+    ->setCellValueExplicit('C20', 'This will not be added to sharedStrings.xml', DataType::TYPE_INLINE);
+
 $spreadsheet->getActiveSheet()
     ->getColumnDimension('B')
     ->setAutoSize(true);

src/PhpSpreadsheet/Writer/Xls/Worksheet.php

@@ -433,6 +433,7 @@ class Worksheet extends BIFFwriter
             } else {
                 switch ($cell->getDatatype()) {
                     case DataType::TYPE_STRING:
+                    case DataType::TYPE_INLINE:
                     case DataType::TYPE_NULL:
                         if ($cVal === '' || $cVal === null) {
                             $this->writeBlank($row, $column, $xfIndex);

src/PhpSpreadsheet/Writer/Xlsx/Worksheet.php

@@ -1189,10 +1189,12 @@ class Worksheet extends WriterPart
     {
         $objWriter->writeAttribute('t', $mappedType);
         if (!$cellValue instanceof RichText) {
+            $objWriter->startElement('is');
             $objWriter->writeElement(
                 't',
                 StringHelper::controlCharacterPHP2OOXML(htmlspecialchars($cellValue, Settings::htmlEntityFlags()))
             );
+            $objWriter->endElement();
         } elseif ($cellValue instanceof RichText) {
             $objWriter->startElement('is');
             $this->getParentWriter()->getWriterPartstringtable()->writeRichText($objWriter, $cellValue);