first commit

modules/x13import/tools/Spout/Writer/XLSX/Helper/BorderHelper.php

@@ -0,0 +1,68 @@
+<?php
+
+namespace Box\Spout\Writer\XLSX\Helper;
+
+use Box\Spout\Writer\Style\Border;
+use Box\Spout\Writer\Style\BorderPart;
+
+class BorderHelper
+{
+    public static $xlsxStyleMap = [
+        Border::STYLE_SOLID => [
+            Border::WIDTH_THIN => 'thin',
+            Border::WIDTH_MEDIUM => 'medium',
+            Border::WIDTH_THICK => 'thick'
+        ],
+        Border::STYLE_DOTTED => [
+            Border::WIDTH_THIN => 'dotted',
+            Border::WIDTH_MEDIUM => 'dotted',
+            Border::WIDTH_THICK => 'dotted',
+        ],
+        Border::STYLE_DASHED => [
+            Border::WIDTH_THIN => 'dashed',
+            Border::WIDTH_MEDIUM => 'mediumDashed',
+            Border::WIDTH_THICK => 'mediumDashed',
+        ],
+        Border::STYLE_DOUBLE => [
+            Border::WIDTH_THIN => 'double',
+            Border::WIDTH_MEDIUM => 'double',
+            Border::WIDTH_THICK => 'double',
+        ],
+        Border::STYLE_NONE => [
+            Border::WIDTH_THIN => 'none',
+            Border::WIDTH_MEDIUM => 'none',
+            Border::WIDTH_THICK => 'none',
+        ],
+    ];
+
+    /**
+     * @param BorderPart $borderPart
+     * @return string
+     */
+    public static function serializeBorderPart(BorderPart $borderPart)
+    {
+        $borderStyle = self::getBorderStyle($borderPart);
+
+        $colorEl = $borderPart->getColor() ? sprintf('<color rgb="%s"/>', $borderPart->getColor()) : '';
+        $partEl = sprintf(
+            '<%s style="%s">%s</%s>',
+            $borderPart->getName(),
+            $borderStyle,
+            $colorEl,
+            $borderPart->getName()
+        );
+
+        return $partEl . PHP_EOL;
+    }
+
+    /**
+     * Get the style definition from the style map
+     *
+     * @param BorderPart $borderPart
+     * @return string
+     */
+    protected static function getBorderStyle(BorderPart $borderPart)
+    {
+        return self::$xlsxStyleMap[$borderPart->getStyle()][$borderPart->getWidth()];
+    }
+}

modules/x13import/tools/Spout/Writer/XLSX/Helper/FileSystemHelper.php

@@ -0,0 +1,371 @@
+<?php
+
+namespace Box\Spout\Writer\XLSX\Helper;
+
+use Box\Spout\Writer\Common\Helper\ZipHelper;
+use Box\Spout\Writer\XLSX\Internal\Worksheet;
+
+/**
+ * Class FileSystemHelper
+ * This class provides helper functions to help with the file system operations
+ * like files/folders creation & deletion for XLSX files
+ *
+ * @package Box\Spout\Writer\XLSX\Helper
+ */
+class FileSystemHelper extends \Box\Spout\Common\Helper\FileSystemHelper
+{
+    const APP_NAME = 'Spout';
+
+    const RELS_FOLDER_NAME = '_rels';
+    const DOC_PROPS_FOLDER_NAME = 'docProps';
+    const XL_FOLDER_NAME = 'xl';
+    const WORKSHEETS_FOLDER_NAME = 'worksheets';
+
+    const RELS_FILE_NAME = '.rels';
+    const APP_XML_FILE_NAME = 'app.xml';
+    const CORE_XML_FILE_NAME = 'core.xml';
+    const CONTENT_TYPES_XML_FILE_NAME = '[Content_Types].xml';
+    const WORKBOOK_XML_FILE_NAME = 'workbook.xml';
+    const WORKBOOK_RELS_XML_FILE_NAME = 'workbook.xml.rels';
+    const STYLES_XML_FILE_NAME = 'styles.xml';
+
+    /** @var string Path to the root folder inside the temp folder where the files to create the XLSX will be stored */
+    protected $rootFolder;
+
+    /** @var string Path to the "_rels" folder inside the root folder */
+    protected $relsFolder;
+
+    /** @var string Path to the "docProps" folder inside the root folder */
+    protected $docPropsFolder;
+
+    /** @var string Path to the "xl" folder inside the root folder */
+    protected $xlFolder;
+
+    /** @var string Path to the "_rels" folder inside the "xl" folder */
+    protected $xlRelsFolder;
+
+    /** @var string Path to the "worksheets" folder inside the "xl" folder */
+    protected $xlWorksheetsFolder;
+
+    /**
+     * @return string
+     */
+    public function getRootFolder()
+    {
+        return $this->rootFolder;
+    }
+
+    /**
+     * @return string
+     */
+    public function getXlFolder()
+    {
+        return $this->xlFolder;
+    }
+
+    /**
+     * @return string
+     */
+    public function getXlWorksheetsFolder()
+    {
+        return $this->xlWorksheetsFolder;
+    }
+
+    /**
+     * Creates all the folders needed to create a XLSX file, as well as the files that won't change.
+     *
+     * @return void
+     * @throws \Box\Spout\Common\Exception\IOException If unable to create at least one of the base folders
+     */
+    public function createBaseFilesAndFolders()
+    {
+        $this
+            ->createRootFolder()
+            ->createRelsFolderAndFile()
+            ->createDocPropsFolderAndFiles()
+            ->createXlFolderAndSubFolders();
+    }
+
+    /**
+     * Creates the folder that will be used as root
+     *
+     * @return FileSystemHelper
+     * @throws \Box\Spout\Common\Exception\IOException If unable to create the folder
+     */
+    protected function createRootFolder()
+    {
+        $this->rootFolder = $this->createFolder($this->baseFolderRealPath, uniqid('xlsx', true));
+        return $this;
+    }
+
+    /**
+     * Creates the "_rels" folder under the root folder as well as the ".rels" file in it
+     *
+     * @return FileSystemHelper
+     * @throws \Box\Spout\Common\Exception\IOException If unable to create the folder or the ".rels" file
+     */
+    protected function createRelsFolderAndFile()
+    {
+        $this->relsFolder = $this->createFolder($this->rootFolder, self::RELS_FOLDER_NAME);
+
+        $this->createRelsFile();
+
+        return $this;
+    }
+
+    /**
+     * Creates the ".rels" file under the "_rels" folder (under root)
+     *
+     * @return FileSystemHelper
+     * @throws \Box\Spout\Common\Exception\IOException If unable to create the file
+     */
+    protected function createRelsFile()
+    {
+        $relsFileContents = <<<EOD
+<?xml version="1.0" encoding="UTF-8"?>
+<Relationships xmlns="http://schemas.openxmlformats.org/package/2006/relationships">
+    <Relationship Id="rIdWorkbook" Type="http://schemas.openxmlformats.org/officeDocument/2006/relationships/officeDocument" Target="xl/workbook.xml"/>
+    <Relationship Id="rIdCore" Type="http://schemas.openxmlformats.org/officedocument/2006/relationships/metadata/core-properties" Target="docProps/core.xml"/>
+    <Relationship Id="rIdApp" Type="http://schemas.openxmlformats.org/officeDocument/2006/relationships/extended-properties" Target="docProps/app.xml"/>
+</Relationships>
+EOD;
+
+        $this->createFileWithContents($this->relsFolder, self::RELS_FILE_NAME, $relsFileContents);
+
+        return $this;
+    }
+
+    /**
+     * Creates the "docProps" folder under the root folder as well as the "app.xml" and "core.xml" files in it
+     *
+     * @return FileSystemHelper
+     * @throws \Box\Spout\Common\Exception\IOException If unable to create the folder or one of the files
+     */
+    protected function createDocPropsFolderAndFiles()
+    {
+        $this->docPropsFolder = $this->createFolder($this->rootFolder, self::DOC_PROPS_FOLDER_NAME);
+
+        $this->createAppXmlFile();
+        $this->createCoreXmlFile();
+
+        return $this;
+    }
+
+    /**
+     * Creates the "app.xml" file under the "docProps" folder
+     *
+     * @return FileSystemHelper
+     * @throws \Box\Spout\Common\Exception\IOException If unable to create the file
+     */
+    protected function createAppXmlFile()
+    {
+        $appName = self::APP_NAME;
+        $appXmlFileContents = <<<EOD
+<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
+<Properties xmlns="http://schemas.openxmlformats.org/officeDocument/2006/extended-properties">
+    <Application>$appName</Application>
+    <TotalTime>0</TotalTime>
+</Properties>
+EOD;
+
+        $this->createFileWithContents($this->docPropsFolder, self::APP_XML_FILE_NAME, $appXmlFileContents);
+
+        return $this;
+    }
+
+    /**
+     * Creates the "core.xml" file under the "docProps" folder
+     *
+     * @return FileSystemHelper
+     * @throws \Box\Spout\Common\Exception\IOException If unable to create the file
+     */
+    protected function createCoreXmlFile()
+    {
+        $createdDate = (new \DateTime())->format(\DateTime::W3C);
+        $coreXmlFileContents = <<<EOD
+<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
+<cp:coreProperties xmlns:cp="http://schemas.openxmlformats.org/package/2006/metadata/core-properties" xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:dcmitype="http://purl.org/dc/dcmitype/" xmlns:dcterms="http://purl.org/dc/terms/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
+    <dcterms:created xsi:type="dcterms:W3CDTF">$createdDate</dcterms:created>
+    <dcterms:modified xsi:type="dcterms:W3CDTF">$createdDate</dcterms:modified>
+    <cp:revision>0</cp:revision>
+</cp:coreProperties>
+EOD;
+
+        $this->createFileWithContents($this->docPropsFolder, self::CORE_XML_FILE_NAME, $coreXmlFileContents);
+
+        return $this;
+    }
+
+    /**
+     * Creates the "xl" folder under the root folder as well as its subfolders
+     *
+     * @return FileSystemHelper
+     * @throws \Box\Spout\Common\Exception\IOException If unable to create at least one of the folders
+     */
+    protected function createXlFolderAndSubFolders()
+    {
+        $this->xlFolder = $this->createFolder($this->rootFolder, self::XL_FOLDER_NAME);
+        $this->createXlRelsFolder();
+        $this->createXlWorksheetsFolder();
+
+        return $this;
+    }
+
+    /**
+     * Creates the "_rels" folder under the "xl" folder
+     *
+     * @return FileSystemHelper
+     * @throws \Box\Spout\Common\Exception\IOException If unable to create the folder
+     */
+    protected function createXlRelsFolder()
+    {
+        $this->xlRelsFolder = $this->createFolder($this->xlFolder, self::RELS_FOLDER_NAME);
+        return $this;
+    }
+
+    /**
+     * Creates the "worksheets" folder under the "xl" folder
+     *
+     * @return FileSystemHelper
+     * @throws \Box\Spout\Common\Exception\IOException If unable to create the folder
+     */
+    protected function createXlWorksheetsFolder()
+    {
+        $this->xlWorksheetsFolder = $this->createFolder($this->xlFolder, self::WORKSHEETS_FOLDER_NAME);
+        return $this;
+    }
+
+    /**
+     * Creates the "[Content_Types].xml" file under the root folder
+     *
+     * @param Worksheet[] $worksheets
+     * @return FileSystemHelper
+     */
+    public function createContentTypesFile($worksheets)
+    {
+        $contentTypesXmlFileContents = <<<EOD
+<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
+<Types xmlns="http://schemas.openxmlformats.org/package/2006/content-types">
+    <Default ContentType="application/xml" Extension="xml"/>
+    <Default ContentType="application/vnd.openxmlformats-package.relationships+xml" Extension="rels"/>
+    <Override ContentType="application/vnd.openxmlformats-officedocument.spreadsheetml.sheet.main+xml" PartName="/xl/workbook.xml"/>
+EOD;
+
+    /** @var Worksheet $worksheet */
+    foreach ($worksheets as $worksheet) {
+        $contentTypesXmlFileContents .= '<Override ContentType="application/vnd.openxmlformats-officedocument.spreadsheetml.worksheet+xml" PartName="/xl/worksheets/sheet' . $worksheet->getId() . '.xml"/>';
+    }
+
+    $contentTypesXmlFileContents .= <<<EOD
+    <Override ContentType="application/vnd.openxmlformats-officedocument.spreadsheetml.styles+xml" PartName="/xl/styles.xml"/>
+    <Override ContentType="application/vnd.openxmlformats-officedocument.spreadsheetml.sharedStrings+xml" PartName="/xl/sharedStrings.xml"/>
+    <Override ContentType="application/vnd.openxmlformats-package.core-properties+xml" PartName="/docProps/core.xml"/>
+    <Override ContentType="application/vnd.openxmlformats-officedocument.extended-properties+xml" PartName="/docProps/app.xml"/>
+</Types>
+EOD;
+
+        $this->createFileWithContents($this->rootFolder, self::CONTENT_TYPES_XML_FILE_NAME, $contentTypesXmlFileContents);
+
+        return $this;
+    }
+
+    /**
+     * Creates the "workbook.xml" file under the "xl" folder
+     *
+     * @param Worksheet[] $worksheets
+     * @return FileSystemHelper
+     */
+    public function createWorkbookFile($worksheets)
+    {
+        $workbookXmlFileContents = <<<EOD
+<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
+<workbook xmlns="http://schemas.openxmlformats.org/spreadsheetml/2006/main" xmlns:r="http://schemas.openxmlformats.org/officeDocument/2006/relationships">
+    <sheets>
+EOD;
+
+        /** @noinspection PhpUnnecessaryFullyQualifiedNameInspection */
+        $escaper = \Box\Spout\Common\Escaper\XLSX::getInstance();
+
+        /** @var Worksheet $worksheet */
+        foreach ($worksheets as $worksheet) {
+            $worksheetName = $worksheet->getExternalSheet()->getName();
+            $worksheetId = $worksheet->getId();
+            $workbookXmlFileContents .= '<sheet name="' . $escaper->escape($worksheetName) . '" sheetId="' . $worksheetId . '" r:id="rIdSheet' . $worksheetId . '"/>';
+        }
+
+        $workbookXmlFileContents .= <<<EOD
+    </sheets>
+</workbook>
+EOD;
+
+        $this->createFileWithContents($this->xlFolder, self::WORKBOOK_XML_FILE_NAME, $workbookXmlFileContents);
+
+        return $this;
+    }
+
+    /**
+     * Creates the "workbook.xml.res" file under the "xl/_res" folder
+     *
+     * @param Worksheet[] $worksheets
+     * @return FileSystemHelper
+     */
+    public function createWorkbookRelsFile($worksheets)
+    {
+        $workbookRelsXmlFileContents = <<<EOD
+<?xml version="1.0" encoding="UTF-8"?>
+<Relationships xmlns="http://schemas.openxmlformats.org/package/2006/relationships">
+    <Relationship Id="rIdStyles" Target="styles.xml" Type="http://schemas.openxmlformats.org/officeDocument/2006/relationships/styles"/>
+    <Relationship Id="rIdSharedStrings" Target="sharedStrings.xml" Type="http://schemas.openxmlformats.org/officeDocument/2006/relationships/sharedStrings"/>
+EOD;
+
+        /** @var Worksheet $worksheet */
+        foreach ($worksheets as $worksheet) {
+            $worksheetId = $worksheet->getId();
+            $workbookRelsXmlFileContents .= '<Relationship Id="rIdSheet' . $worksheetId . '" Target="worksheets/sheet' . $worksheetId . '.xml" Type="http://schemas.openxmlformats.org/officeDocument/2006/relationships/worksheet"/>';
+        }
+
+        $workbookRelsXmlFileContents .= '</Relationships>';
+
+        $this->createFileWithContents($this->xlRelsFolder, self::WORKBOOK_RELS_XML_FILE_NAME, $workbookRelsXmlFileContents);
+
+        return $this;
+    }
+
+    /**
+     * Creates the "styles.xml" file under the "xl" folder
+     *
+     * @param StyleHelper $styleHelper
+     * @return FileSystemHelper
+     */
+    public function createStylesFile($styleHelper)
+    {
+        $stylesXmlFileContents = $styleHelper->getStylesXMLFileContent();
+        $this->createFileWithContents($this->xlFolder, self::STYLES_XML_FILE_NAME, $stylesXmlFileContents);
+
+        return $this;
+    }
+
+    /**
+     * Zips the root folder and streams the contents of the zip into the given stream
+     *
+     * @param resource $streamPointer Pointer to the stream to copy the zip
+     * @return void
+     */
+    public function zipRootFolderAndCopyToStream($streamPointer)
+    {
+        $zipHelper = new ZipHelper($this->rootFolder);
+
+        // In order to have the file's mime type detected properly, files need to be added
+        // to the zip file in a particular order.
+        // "[Content_Types].xml" then at least 2 files located in "xl" folder should be zipped first.
+        $zipHelper->addFileToArchive($this->rootFolder, self::CONTENT_TYPES_XML_FILE_NAME);
+        $zipHelper->addFileToArchive($this->rootFolder, self::XL_FOLDER_NAME . '/' . self::WORKBOOK_XML_FILE_NAME);
+        $zipHelper->addFileToArchive($this->rootFolder, self::XL_FOLDER_NAME . '/' . self::STYLES_XML_FILE_NAME);
+
+        $zipHelper->addFolderToArchive($this->rootFolder, ZipHelper::EXISTING_FILES_SKIP);
+        $zipHelper->closeArchiveAndCopyToStream($streamPointer);
+
+        // once the zip is copied, remove it
+        $this->deleteFile($zipHelper->getZipFilePath());
+    }
+}

modules/x13import/tools/Spout/Writer/XLSX/Helper/SharedStringsHelper.php

@@ -0,0 +1,107 @@
+<?php
+
+namespace Box\Spout\Writer\XLSX\Helper;
+
+use Box\Spout\Common\Exception\IOException;
+
+/**
+ * Class SharedStringsHelper
+ * This class provides helper functions to write shared strings
+ *
+ * @package Box\Spout\Writer\XLSX\Helper
+ */
+class SharedStringsHelper
+{
+    const SHARED_STRINGS_FILE_NAME = 'sharedStrings.xml';
+
+    const SHARED_STRINGS_XML_FILE_FIRST_PART_HEADER = <<<EOD
+<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
+<sst xmlns="http://schemas.openxmlformats.org/spreadsheetml/2006/main"
+EOD;
+
+    /**
+     * This number must be really big so that the no generated file will have more strings than that.
+     * If the strings number goes above, characters will be overwritten in an unwanted way and will corrupt the file.
+     */
+    const DEFAULT_STRINGS_COUNT_PART = 'count="9999999999999" uniqueCount="9999999999999"';
+
+    /** @var resource Pointer to the sharedStrings.xml file */
+    protected $sharedStringsFilePointer;
+
+    /** @var int Number of shared strings already written */
+    protected $numSharedStrings = 0;
+
+    /** @var \Box\Spout\Common\Escaper\XLSX Strings escaper */
+    protected $stringsEscaper;
+
+    /**
+     * @param string $xlFolder Path to the "xl" folder
+     */
+    public function __construct($xlFolder)
+    {
+        $sharedStringsFilePath = $xlFolder . '/' . self::SHARED_STRINGS_FILE_NAME;
+        $this->sharedStringsFilePointer = fopen($sharedStringsFilePath, 'w');
+
+        $this->throwIfSharedStringsFilePointerIsNotAvailable();
+
+        // the headers is split into different parts so that we can fseek and put in the correct count and uniqueCount later
+        $header = self::SHARED_STRINGS_XML_FILE_FIRST_PART_HEADER . ' ' . self::DEFAULT_STRINGS_COUNT_PART . '>';
+        fwrite($this->sharedStringsFilePointer, $header);
+
+        /** @noinspection PhpUnnecessaryFullyQualifiedNameInspection */
+        $this->stringsEscaper = \Box\Spout\Common\Escaper\XLSX::getInstance();
+    }
+
+    /**
+     * Checks if the book has been created. Throws an exception if not created yet.
+     *
+     * @return void
+     * @throws \Box\Spout\Common\Exception\IOException If the sheet data file cannot be opened for writing
+     */
+    protected function throwIfSharedStringsFilePointerIsNotAvailable()
+    {
+        if (!$this->sharedStringsFilePointer) {
+            throw new IOException('Unable to open shared strings file for writing.');
+        }
+    }
+
+    /**
+     * Writes the given string into the sharedStrings.xml file.
+     * Starting and ending whitespaces are preserved.
+     *
+     * @param string $string
+     * @return int ID of the written shared string
+     */
+    public function writeString($string)
+    {
+        fwrite($this->sharedStringsFilePointer, '<si><t xml:space="preserve">' . $this->stringsEscaper->escape($string) . '</t></si>');
+        $this->numSharedStrings++;
+
+        // Shared string ID is zero-based
+        return ($this->numSharedStrings - 1);
+    }
+
+    /**
+     * Finishes writing the data in the sharedStrings.xml file and closes the file.
+     *
+     * @return void
+     */
+    public function close()
+    {
+        if (!is_resource($this->sharedStringsFilePointer)) {
+            return;
+        }
+
+        fwrite($this->sharedStringsFilePointer, '</sst>');
+
+        // Replace the default strings count with the actual number of shared strings in the file header
+        $firstPartHeaderLength = strlen(self::SHARED_STRINGS_XML_FILE_FIRST_PART_HEADER);
+        $defaultStringsCountPartLength = strlen(self::DEFAULT_STRINGS_COUNT_PART);
+
+        // Adding 1 to take into account the space between the last xml attribute and "count"
+        fseek($this->sharedStringsFilePointer, $firstPartHeaderLength + 1);
+        fwrite($this->sharedStringsFilePointer, sprintf("%-{$defaultStringsCountPartLength}s", 'count="' . $this->numSharedStrings . '" uniqueCount="' . $this->numSharedStrings . '"'));
+
+        fclose($this->sharedStringsFilePointer);
+    }
+}

modules/x13import/tools/Spout/Writer/XLSX/Helper/StyleHelper.php

@@ -0,0 +1,344 @@
+<?php
+
+namespace Box\Spout\Writer\XLSX\Helper;
+
+use Box\Spout\Writer\Common\Helper\AbstractStyleHelper;
+use Box\Spout\Writer\Style\Color;
+use Box\Spout\Writer\Style\Style;
+
+/**
+ * Class StyleHelper
+ * This class provides helper functions to manage styles
+ *
+ * @package Box\Spout\Writer\XLSX\Helper
+ */
+class StyleHelper extends AbstractStyleHelper
+{
+    /**
+     * @var array
+     */
+    protected $registeredFills = [];
+
+    /**
+     * @var array [STYLE_ID] => [FILL_ID] maps a style to a fill declaration
+     */
+    protected $styleIdToFillMappingTable = [];
+
+    /**
+     * Excel preserves two default fills with index 0 and 1
+     * Since Excel is the dominant vendor - we play along here
+     *
+     * @var int The fill index counter for custom fills.
+     */
+    protected $fillIndex = 2;
+
+    /**
+     * @var array
+     */
+    protected $registeredBorders = [];
+
+    /**
+     * @var array [STYLE_ID] => [BORDER_ID] maps a style to a border declaration
+     */
+    protected $styleIdToBorderMappingTable = [];
+
+    /**
+     * XLSX specific operations on the registered styles
+     *
+     * @param \Box\Spout\Writer\Style\Style $style
+     * @return \Box\Spout\Writer\Style\Style
+     */
+    public function registerStyle($style)
+    {
+        $registeredStyle = parent::registerStyle($style);
+        $this->registerFill($registeredStyle);
+        $this->registerBorder($registeredStyle);
+        return $registeredStyle;
+    }
+
+    /**
+     * Register a fill definition
+     *
+     * @param \Box\Spout\Writer\Style\Style $style
+     */
+    protected function registerFill($style)
+    {
+        $styleId = $style->getId();
+
+        // Currently - only solid backgrounds are supported
+        // so $backgroundColor is a scalar value (RGB Color)
+        $backgroundColor = $style->getBackgroundColor();
+
+        if ($backgroundColor) {
+            $isBackgroundColorRegistered = isset($this->registeredFills[$backgroundColor]);
+
+            // We need to track the already registered background definitions
+            if ($isBackgroundColorRegistered) {
+                $registeredStyleId = $this->registeredFills[$backgroundColor];
+                $registeredFillId = $this->styleIdToFillMappingTable[$registeredStyleId];
+                $this->styleIdToFillMappingTable[$styleId] = $registeredFillId;
+            } else {
+                $this->registeredFills[$backgroundColor] = $styleId;
+                $this->styleIdToFillMappingTable[$styleId] = $this->fillIndex++;
+            }
+
+        } else {
+            // The fillId maps a style to a fill declaration
+            // When there is no background color definition - we default to 0
+            $this->styleIdToFillMappingTable[$styleId] = 0;
+        }
+    }
+
+    /**
+     * Register a border definition
+     *
+     * @param \Box\Spout\Writer\Style\Style $style
+     */
+    protected function registerBorder($style)
+    {
+        $styleId = $style->getId();
+
+        if ($style->shouldApplyBorder()) {
+            $border = $style->getBorder();
+            $serializedBorder = serialize($border);
+
+            $isBorderAlreadyRegistered = isset($this->registeredBorders[$serializedBorder]);
+
+            if ($isBorderAlreadyRegistered) {
+                $registeredStyleId = $this->registeredBorders[$serializedBorder];
+                $registeredBorderId = $this->styleIdToBorderMappingTable[$registeredStyleId];
+                $this->styleIdToBorderMappingTable[$styleId] = $registeredBorderId;
+            } else {
+                $this->registeredBorders[$serializedBorder] = $styleId;
+                $this->styleIdToBorderMappingTable[$styleId] = count($this->registeredBorders);
+            }
+
+        } else {
+            // If no border should be applied - the mapping is the default border: 0
+            $this->styleIdToBorderMappingTable[$styleId] = 0;
+        }
+    }
+
+
+    /**
+     * For empty cells, we can specify a style or not. If no style are specified,
+     * then the software default will be applied. But sometimes, it may be useful
+     * to override this default style, for instance if the cell should have a
+     * background color different than the default one or some borders
+     * (fonts property don't really matter here).
+     *
+     * @param int $styleId
+     * @return bool Whether the cell should define a custom style
+     */
+    public function shouldApplyStyleOnEmptyCell($styleId)
+    {
+        $hasStyleCustomFill = (isset($this->styleIdToFillMappingTable[$styleId]) && $this->styleIdToFillMappingTable[$styleId] !== 0);
+        $hasStyleCustomBorders = (isset($this->styleIdToBorderMappingTable[$styleId]) && $this->styleIdToBorderMappingTable[$styleId] !== 0);
+
+        return ($hasStyleCustomFill || $hasStyleCustomBorders);
+    }
+
+
+    /**
+     * Returns the content of the "styles.xml" file, given a list of styles.
+     *
+     * @return string
+     */
+    public function getStylesXMLFileContent()
+    {
+        $content = <<<EOD
+<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
+<styleSheet xmlns="http://schemas.openxmlformats.org/spreadsheetml/2006/main">
+EOD;
+
+        $content .= $this->getFontsSectionContent();
+        $content .= $this->getFillsSectionContent();
+        $content .= $this->getBordersSectionContent();
+        $content .= $this->getCellStyleXfsSectionContent();
+        $content .= $this->getCellXfsSectionContent();
+        $content .= $this->getCellStylesSectionContent();
+
+        $content .= <<<EOD
+</styleSheet>
+EOD;
+
+        return $content;
+    }
+
+    /**
+     * Returns the content of the "<fonts>" section.
+     *
+     * @return string
+     */
+    protected function getFontsSectionContent()
+    {
+        $content = '<fonts count="' . count($this->styleIdToStyleMappingTable) . '">';
+
+        /** @var \Box\Spout\Writer\Style\Style $style */
+        foreach ($this->getRegisteredStyles() as $style) {
+            $content .= '<font>';
+
+            $content .= '<sz val="' . $style->getFontSize() . '"/>';
+            $content .= '<color rgb="' . Color::toARGB($style->getFontColor()) . '"/>';
+            $content .= '<name val="' . $style->getFontName() . '"/>';
+
+            if ($style->isFontBold()) {
+                $content .= '<b/>';
+            }
+            if ($style->isFontItalic()) {
+                $content .= '<i/>';
+            }
+            if ($style->isFontUnderline()) {
+                $content .= '<u/>';
+            }
+            if ($style->isFontStrikethrough()) {
+                $content .= '<strike/>';
+            }
+
+            $content .= '</font>';
+        }
+
+        $content .= '</fonts>';
+
+        return $content;
+    }
+
+    /**
+     * Returns the content of the "<fills>" section.
+     *
+     * @return string
+     */
+    protected function getFillsSectionContent()
+    {
+        // Excel reserves two default fills
+        $fillsCount = count($this->registeredFills) + 2;
+        $content = sprintf('<fills count="%d">', $fillsCount);
+
+        $content .= '<fill><patternFill patternType="none"/></fill>';
+        $content .= '<fill><patternFill patternType="gray125"/></fill>';
+
+        // The other fills are actually registered by setting a background color
+        foreach ($this->registeredFills as $styleId) {
+            /** @var Style $style */
+            $style = $this->styleIdToStyleMappingTable[$styleId];
+
+            $backgroundColor = $style->getBackgroundColor();
+            $content .= sprintf(
+                '<fill><patternFill patternType="solid"><fgColor rgb="%s"/></patternFill></fill>',
+                $backgroundColor
+            );
+        }
+
+        $content .= '</fills>';
+
+        return $content;
+    }
+
+    /**
+     * Returns the content of the "<borders>" section.
+     *
+     * @return string
+     */
+    protected function getBordersSectionContent()
+    {
+
+        // There is one default border with index 0
+        $borderCount = count($this->registeredBorders) + 1;
+
+        $content = '<borders count="' . $borderCount . '">';
+
+        // Default border starting at index 0
+        $content .= '<border><left/><right/><top/><bottom/></border>';
+
+        foreach ($this->registeredBorders as $styleId) {
+            /** @var \Box\Spout\Writer\Style\Style $style */
+            $style = $this->styleIdToStyleMappingTable[$styleId];
+            $border = $style->getBorder();
+            $content .= '<border>';
+
+            // @link https://github.com/box/spout/issues/271
+            $sortOrder = ['left', 'right', 'top', 'bottom'];
+
+            foreach ($sortOrder as $partName) {
+                if ($border->hasPart($partName)) {
+                    /** @var $part \Box\Spout\Writer\Style\BorderPart */
+                    $part = $border->getPart($partName);
+                    $content .= BorderHelper::serializeBorderPart($part);
+                }
+
+            }
+
+            $content .= '</border>';
+        }
+
+        $content .= '</borders>';
+
+        return $content;
+    }
+
+    /**
+     * Returns the content of the "<cellStyleXfs>" section.
+     *
+     * @return string
+     */
+    protected function getCellStyleXfsSectionContent()
+    {
+        return <<<EOD
+<cellStyleXfs count="1">
+    <xf borderId="0" fillId="0" fontId="0" numFmtId="0"/>
+</cellStyleXfs>
+EOD;
+    }
+
+    /**
+     * Returns the content of the "<cellXfs>" section.
+     *
+     * @return string
+     */
+    protected function getCellXfsSectionContent()
+    {
+        $registeredStyles = $this->getRegisteredStyles();
+
+        $content = '<cellXfs count="' . count($registeredStyles) . '">';
+
+        foreach ($registeredStyles as $style) {
+            $styleId = $style->getId();
+            $fillId = $this->styleIdToFillMappingTable[$styleId];
+            $borderId = $this->styleIdToBorderMappingTable[$styleId];
+
+            $content .= '<xf numFmtId="0" fontId="' . $styleId . '" fillId="' . $fillId . '" borderId="' . $borderId . '" xfId="0"';
+
+            if ($style->shouldApplyFont()) {
+                $content .= ' applyFont="1"';
+            }
+
+            $content .= sprintf(' applyBorder="%d"', $style->shouldApplyBorder() ? 1 : 0);
+
+            if ($style->shouldWrapText()) {
+                $content .= ' applyAlignment="1">';
+                $content .= '<alignment wrapText="1"/>';
+                $content .= '</xf>';
+            } else {
+                $content .= '/>';
+            }
+        }
+
+        $content .= '</cellXfs>';
+
+        return $content;
+    }
+
+    /**
+     * Returns the content of the "<cellStyles>" section.
+     *
+     * @return string
+     */
+    protected function getCellStylesSectionContent()
+    {
+        return <<<EOD
+<cellStyles count="1">
+    <cellStyle builtinId="0" name="Normal" xfId="0"/>
+</cellStyles>
+EOD;
+    }
+}