ODS writer

Added ODS writer
Refactored XLSX writer to abstract some pieces into an abstract multi-sheets writer
Created an abstract style helper
Moved shared components around

src/Spout/Writer/Common/Helper/AbstractStyleHelper.php

@@ -0,0 +1,136 @@
+<?php
+
+namespace Box\Spout\Writer\Common\Helper;
+
+/**
+ * Class AbstractStyleHelper
+ * This class provides helper functions to manage styles
+ *
+ * @package Box\Spout\Writer\Common\Helper
+ */
+abstract class AbstractStyleHelper
+{
+    /** @var array [SERIALIZED_STYLE] => [STYLE_ID] mapping table, keeping track of the registered styles */
+    protected $serializedStyleToStyleIdMappingTable = [];
+
+    /** @var array [STYLE_ID] => [STYLE] mapping table, keeping track of the registered styles */
+    protected $styleIdToStyleMappingTable = [];
+
+    /**
+     * @param \Box\Spout\Writer\Style\Style $defaultStyle
+     */
+    public function __construct($defaultStyle)
+    {
+        // This ensures that the default style is the first one to be registered
+        $this->registerStyle($defaultStyle);
+    }
+
+    /**
+     * Registers the given style as a used style.
+     * Duplicate styles won't be registered more than once.
+     *
+     * @param \Box\Spout\Writer\Style\Style $style The style to be registered
+     * @return \Box\Spout\Writer\Style\Style The registered style, updated with an internal ID.
+     */
+    public function registerStyle($style)
+    {
+        $serializedStyle = $style->serialize();
+
+        if (!$this->hasStyleAlreadyBeenRegistered($style)) {
+            $nextStyleId = count($this->serializedStyleToStyleIdMappingTable);
+            $style->setId($nextStyleId);
+
+            $this->serializedStyleToStyleIdMappingTable[$serializedStyle] = $nextStyleId;
+            $this->styleIdToStyleMappingTable[$nextStyleId] = $style;
+        }
+
+        return $this->getStyleFromSerializedStyle($serializedStyle);
+    }
+
+    /**
+     * Returns whether the given style has already been registered.
+     *
+     * @param \Box\Spout\Writer\Style\Style $style
+     * @return bool
+     */
+    protected function hasStyleAlreadyBeenRegistered($style)
+    {
+        $serializedStyle = $style->serialize();
+        return array_key_exists($serializedStyle, $this->serializedStyleToStyleIdMappingTable);
+    }
+
+    /**
+     * Returns the registered style associated to the given serialization.
+     *
+     * @param string $serializedStyle The serialized style from which the actual style should be fetched from
+     * @return \Box\Spout\Writer\Style\Style
+     */
+    protected function getStyleFromSerializedStyle($serializedStyle)
+    {
+        $styleId = $this->serializedStyleToStyleIdMappingTable[$serializedStyle];
+        return $this->styleIdToStyleMappingTable[$styleId];
+    }
+
+    /**
+     * @return \Box\Spout\Writer\Style\Style[] List of registered styles
+     */
+    protected function getRegisteredStyles()
+    {
+        return array_values($this->styleIdToStyleMappingTable);
+    }
+
+    /**
+     * Returns the default style
+     *
+     * @return \Box\Spout\Writer\Style\Style Default style
+     */
+    protected function getDefaultStyle()
+    {
+        // By construction, the default style has ID 0
+        return $this->styleIdToStyleMappingTable[0];
+    }
+
+    /**
+     * Apply additional styles if the given row needs it.
+     * Typically, set "wrap text" if a cell contains a new line.
+     *
+     * @param \Box\Spout\Writer\Style\Style $style The original style
+     * @param array $dataRow The row the style will be applied to
+     * @return \Box\Spout\Writer\Style\Style The updated style
+     */
+    public function applyExtraStylesIfNeeded($style, $dataRow)
+    {
+        $updatedStyle = $this->applyWrapTextIfCellContainsNewLine($style, $dataRow);
+        return $updatedStyle;
+    }
+
+    /**
+     * Set the "wrap text" option if a cell of the given row contains a new line.
+     *
+     * @NOTE: There is a bug on the Mac version of Excel (2011 and below) where new lines
+     *        are ignored even when the "wrap text" option is set. This only occurs with
+     *        inline strings (shared strings do work fine).
+     *        A workaround would be to encode "\n" as "_x000D_" but it does not work
+     *        on the Windows version of Excel...
+     *
+     * @param \Box\Spout\Writer\Style\Style $style The original style
+     * @param array $dataRow The row the style will be applied to
+     * @return \Box\Spout\Writer\Style\Style The eventually updated style
+     */
+    protected function applyWrapTextIfCellContainsNewLine($style, $dataRow)
+    {
+        // if the "wrap text" option is already set, no-op
+        if ($style->shouldWrapText()) {
+            return $style;
+        }
+
+        foreach ($dataRow as $cell) {
+            if (is_string($cell) && strpos($cell, "\n") !== false) {
+                $style->setShouldWrapText();
+                break;
+            }
+        }
+
+        return $style;
+    }
+}

src/Spout/Writer/Common/Helper/CellHelper.php

@@ -0,0 +1,71 @@
+<?php
+
+namespace Box\Spout\Writer\Common\Helper;
+
+/**
+ * Class CellHelper
+ * This class provides helper functions when working with cells
+ *
+ * @package Box\Spout\Writer\Common\Helper
+ */
+class CellHelper
+{
+    /**
+     * Returns the cell index (base 26) associated to the base 10 column index.
+     * Excel uses A to Z letters for column indexing, where A is the 1st column,
+     * Z is the 26th and AA is the 27th.
+     * The mapping is zero based, so that 0 maps to A, B maps to 1, Z to 25 and AA to 26.
+     *
+     * @param int $columnIndex The Excel column index (0, 42, ...)
+     * @return string The associated cell index ('A', 'BC', ...)
+     */
+    public static function getCellIndexFromColumnIndex($columnIndex)
+    {
+        $cellIndex = '';
+        $capitalAAsciiValue = ord('A');
+
+        do {
+            $modulus = $columnIndex % 26;
+            $cellIndex = chr($capitalAAsciiValue + $modulus) . $cellIndex;
+
+            // substracting 1 because it's zero-based
+            $columnIndex = intval($columnIndex / 26) - 1;
+        } while ($columnIndex >= 0);
+
+        return $cellIndex;
+    }
+
+    /**
+     * @param $value
+     * @return bool Whether the given value is a non empty string
+     */
+    public static function isNonEmptyString($value)
+    {
+        return (gettype($value) === 'string' && $value !== '');
+    }
+
+    /**
+     * Returns whether the given value is numeric.
+     * A numeric value is from type "integer" or "double" ("float" is not returned by gettype).
+     *
+     * @param $value
+     * @return bool Whether the given value is numeric
+     */
+    public static function isNumeric($value)
+    {
+        $valueType = gettype($value);
+        return ($valueType === 'integer' || $valueType === 'double');
+    }
+
+    /**
+     * Returns whether the given value is boolean.
+     * "true"/"false" and 0/1 are not booleans.
+     *
+     * @param $value
+     * @return bool Whether the given value is boolean
+     */
+    public static function isBoolean($value)
+    {
+        return gettype($value) === 'boolean';
+    }
+}

src/Spout/Writer/Common/Helper/ZipHelper.php

@@ -0,0 +1,101 @@
+<?php
+
+namespace Box\Spout\Writer\Common\Helper;
+
+/**
+ * Class ZipHelper
+ * This class provides helper functions to create zip files
+ *
+ * @package Box\Spout\Writer\Common\Helper
+ */
+class ZipHelper
+{
+    const ZIP_EXTENSION = '.zip';
+
+    /**
+     * Zips the root folder and streams the contents of the zip into the given stream
+     *
+     * @param string $folderPath Path to the folder to be zipped
+     * @param resource $streamPointer Pointer to the stream to copy the zip
+     * @return void
+     */
+    public function zipFolderAndCopyToStream($folderPath, $streamPointer)
+    {
+        $zipFilePath = $this->getZipFilePath($folderPath);
+        $this->zipFolder($folderPath, $zipFilePath);
+        $this->copyZipToStream($zipFilePath, $streamPointer);
+    }
+
+    /**
+     * @param string $folderPathToZip Path to the folder to be zipped
+     * @return string Path where the zip file of the given folder will be created
+     */
+    public function getZipFilePath($folderPathToZip)
+    {
+        return $folderPathToZip . self::ZIP_EXTENSION;
+    }
+
+    /**
+     * Zips the given folder
+     *
+     * @param string $folderPath Path of the folder to be zipped
+     * @param string $destinationPath Path where the zip file will be created
+     * @return void
+     */
+    public function zipFolder($folderPath, $destinationPath)
+    {
+        $zip = new \ZipArchive();
+        if ($zip->open($destinationPath, \ZipArchive::CREATE)) {
+            $this->addFolderToZip($zip, $folderPath);
+            $zip->close();
+        }
+    }
+
+    /**
+     * @param \ZipArchive $zip
+     * @param string $folderPath Path of the folder to add to the zip
+     * @return void
+     */
+    protected function addFolderToZip($zip, $folderPath)
+    {
+        $folderRealPath = $this->getNormalizedRealPath($folderPath) . '/';
+        $itemIterator = new \RecursiveIteratorIterator(new \RecursiveDirectoryIterator($folderPath, \RecursiveDirectoryIterator::SKIP_DOTS), \RecursiveIteratorIterator::SELF_FIRST);
+
+        foreach ($itemIterator as $itemInfo) {
+            $itemRealPath = $this->getNormalizedRealPath($itemInfo->getPathname());
+            $itemLocalPath = str_replace($folderRealPath, '', $itemRealPath);
+
+            if ($itemInfo->isFile()) {
+                $zip->addFile($itemRealPath, $itemLocalPath);
+            } else if ($itemInfo->isDir()) {
+                $zip->addEmptyDir($itemLocalPath);
+            }
+        }
+    }
+
+    /**
+     * Returns canonicalized absolute pathname, containing only forward slashes.
+     *
+     * @param string $path Path to normalize
+     * @return string Normalized and canonicalized path
+     */
+    protected function getNormalizedRealPath($path)
+    {
+        $realPath = realpath($path);
+        return str_replace(DIRECTORY_SEPARATOR, '/', $realPath);
+    }
+
+    /**
+     * Streams the contents of the zip file into the given stream
+     *
+     * @param string $zipFilePath Path to the zip file
+     * @param resource $pointer Pointer to the stream to copy the zip
+     * @return void
+     */
+    protected function copyZipToStream($zipFilePath, $pointer)
+    {
+        $zipFilePointer = fopen($zipFilePath, 'r');
+        stream_copy_to_stream($zipFilePointer, $pointer);
+        fclose($zipFilePointer);
+    }
+}

src/Spout/Writer/Common/Internal/AbstractWorkbook.php

@@ -0,0 +1,188 @@
+<?php
+
+namespace Box\Spout\Writer\Common\Internal;
+
+use Box\Spout\Writer\Exception\SheetNotFoundException;
+
+/**
+ * Class Workbook
+ * Represents a workbook within a spreadsheet file.
+ * It provides the functions to work with worksheets.
+ *
+ * @package Box\Spout\Writer\Common
+ */
+abstract class AbstractWorkbook implements WorkbookInterface
+{
+    /** @var bool Whether new sheets should be automatically created when the max rows limit per sheet is reached */
+    protected $shouldCreateNewSheetsAutomatically;
+
+    /** @var WorksheetInterface[] Array containing the workbook's sheets */
+    protected $worksheets = [];
+
+    /** @var WorksheetInterface The worksheet where data will be written to */
+    protected $currentWorksheet;
+
+    /**
+     * @param bool $shouldCreateNewSheetsAutomatically
+     * @param \Box\Spout\Writer\Style\Style $defaultRowStyle
+     * @throws \Box\Spout\Common\Exception\IOException If unable to create at least one of the base folders
+     */
+    public function __construct($shouldCreateNewSheetsAutomatically, $defaultRowStyle)
+    {
+        $this->shouldCreateNewSheetsAutomatically = $shouldCreateNewSheetsAutomatically;
+    }
+
+    /**
+     * @return \Box\Spout\Writer\Common\Helper\AbstractStyleHelper The specific style helper
+     */
+    abstract protected function getStyleHelper();
+
+    /**
+     * @return int Maximum number of rows/columns a sheet can contain
+     */
+    abstract protected function getMaxRowsPerWorksheet();
+
+    /**
+     * Creates a new sheet in the workbook. The current sheet remains unchanged.
+     *
+     * @return WorksheetInterface The created sheet
+     * @throws \Box\Spout\Common\Exception\IOException If unable to open the sheet for writing
+     */
+    abstract public function addNewSheet();
+
+    /**
+     * Creates a new sheet in the workbook and make it the current sheet.
+     * The writing will resume where it stopped (i.e. data won't be truncated).
+     *
+     * @return WorksheetInterface The created sheet
+     * @throws \Box\Spout\Common\Exception\IOException If unable to open the sheet for writing
+     */
+    public function addNewSheetAndMakeItCurrent()
+    {
+        $worksheet = $this->addNewSheet();
+        $this->setCurrentWorksheet($worksheet);
+
+        return $worksheet;
+    }
+
+    /**
+     * @return WorksheetInterface[] All the workbook's sheets
+     */
+    public function getWorksheets()
+    {
+        return $this->worksheets;
+    }
+
+    /**
+     * Returns the current sheet
+     *
+     * @return WorksheetInterface The current sheet
+     */
+    public function getCurrentWorksheet()
+    {
+        return $this->currentWorksheet;
+    }
+
+    /**
+     * Sets the given sheet as the current one. New data will be written to this sheet.
+     * The writing will resume where it stopped (i.e. data won't be truncated).
+     *
+     * @param \Box\Spout\Writer\Common\Sheet $sheet The "external" sheet to set as current
+     * @return void
+     * @throws \Box\Spout\Writer\Exception\SheetNotFoundException If the given sheet does not exist in the workbook
+     */
+    public function setCurrentSheet($sheet)
+    {
+        $worksheet = $this->getWorksheetFromExternalSheet($sheet);
+        if ($worksheet !== null) {
+            $this->currentWorksheet = $worksheet;
+        } else {
+            throw new SheetNotFoundException('The given sheet does not exist in the workbook.');
+        }
+    }
+
+    /**
+     * @param WorksheetInterface $worksheet
+     * @return void
+     */
+    protected function setCurrentWorksheet($worksheet)
+    {
+        $this->currentWorksheet = $worksheet;
+    }
+
+    /**
+     * Returns the worksheet associated to the given external sheet.
+     *
+     * @param \Box\Spout\Writer\Common\Sheet $sheet
+     * @return WorksheetInterface|null The worksheet associated to the given external sheet or null if not found.
+     */
+    protected function getWorksheetFromExternalSheet($sheet)
+    {
+        $worksheetFound = null;
+
+        foreach ($this->worksheets as $worksheet) {
+            if ($worksheet->getExternalSheet() === $sheet) {
+                $worksheetFound = $worksheet;
+                break;
+            }
+        }
+
+        return $worksheetFound;
+    }
+
+    /**
+     * Adds data to the current sheet.
+     * If shouldCreateNewSheetsAutomatically option is set to true, it will handle pagination
+     * with the creation of new worksheets if one worksheet has reached its maximum capicity.
+     *
+     * @param array $dataRow Array containing data to be written.
+     *          Example $dataRow = ['data1', 1234, null, '', 'data5'];
+     * @param \Box\Spout\Writer\Style\Style $style Style to be applied to the row.
+     * @return void
+     * @throws \Box\Spout\Common\Exception\IOException If trying to create a new sheet and unable to open the sheet for writing
+     * @throws \Box\Spout\Writer\Exception\WriterException If unable to write data
+     */
+    public function addRowToCurrentWorksheet($dataRow, $style)
+    {
+        $currentWorksheet = $this->getCurrentWorksheet();
+        $hasReachedMaxRows = $this->hasCurrentWorkseetReachedMaxRows();
+        $styleHelper = $this->getStyleHelper();
+
+        // if we reached the maximum number of rows for the current sheet...
+        if ($hasReachedMaxRows) {
+            // ... continue writing in a new sheet if option set
+            if ($this->shouldCreateNewSheetsAutomatically) {
+                $currentWorksheet = $this->addNewSheetAndMakeItCurrent();
+
+                $updatedStyle = $styleHelper->applyExtraStylesIfNeeded($style, $dataRow);
+                $registeredStyle = $styleHelper->registerStyle($updatedStyle);
+                $currentWorksheet->addRow($dataRow, $registeredStyle);
+            } else {
+                // otherwise, do nothing as the data won't be read anyways
+            }
+        } else {
+            $updatedStyle = $styleHelper->applyExtraStylesIfNeeded($style, $dataRow);
+            $registeredStyle = $styleHelper->registerStyle($updatedStyle);
+            $currentWorksheet->addRow($dataRow, $registeredStyle);
+        }
+    }
+
+    /**
+     * @return bool Whether the current worksheet has reached the maximum number of rows per sheet.
+     */
+    protected function hasCurrentWorkseetReachedMaxRows()
+    {
+        $currentWorksheet = $this->getCurrentWorksheet();
+        return ($currentWorksheet->getLastWrittenRowIndex() >= $this->getMaxRowsPerWorksheet());
+    }
+
+    /**
+     * Closes the workbook and all its associated sheets.
+     * All the necessary files are written to disk and zipped together to create the ODS file.
+     * All the temporary files are then deleted.
+     *
+     * @param resource $finalFilePointer Pointer to the ODS that will be created
+     * @return void
+     */
+    abstract public function close($finalFilePointer);
+}

src/Spout/Writer/Common/Internal/WorkbookInterface.php

@@ -0,0 +1,74 @@
+<?php
+
+namespace Box\Spout\Writer\Common\Internal;
+
+/**
+ * Interface WorkbookInterface
+ *
+ * @package Box\Spout\Writer\Common\Internal
+ */
+interface WorkbookInterface
+{
+    /**
+     * Creates a new sheet in the workbook. The current sheet remains unchanged.
+     *
+     * @return WorksheetInterface The created sheet
+     * @throws \Box\Spout\Common\Exception\IOException If unable to open the sheet for writing
+     */
+    public function addNewSheet();
+
+    /**
+     * Creates a new sheet in the workbook and make it the current sheet.
+     * The writing will resume where it stopped (i.e. data won't be truncated).
+     *
+     * @return WorksheetInterface The created sheet
+     * @throws \Box\Spout\Common\Exception\IOException If unable to open the sheet for writing
+     */
+    public function addNewSheetAndMakeItCurrent();
+
+    /**
+     * @return WorksheetInterface[] All the workbook's sheets
+     */
+    public function getWorksheets();
+
+    /**
+     * Returns the current sheet
+     *
+     * @return WorksheetInterface The current sheet
+     */
+    public function getCurrentWorksheet();
+
+    /**
+     * Sets the given sheet as the current one. New data will be written to this sheet.
+     * The writing will resume where it stopped (i.e. data won't be truncated).
+     *
+     * @param \Box\Spout\Writer\Common\Sheet $sheet The "external" sheet to set as current
+     * @return void
+     * @throws \Box\Spout\Writer\Exception\SheetNotFoundException If the given sheet does not exist in the workbook
+     */
+    public function setCurrentSheet($sheet);
+
+    /**
+     * Adds data to the current sheet.
+     * If shouldCreateNewSheetsAutomatically option is set to true, it will handle pagination
+     * with the creation of new worksheets if one worksheet has reached its maximum capicity.
+     *
+     * @param array $dataRow Array containing data to be written.
+     *          Example $dataRow = ['data1', 1234, null, '', 'data5'];
+     * @param \Box\Spout\Writer\Style\Style $style Style to be applied to the row.
+     * @return void
+     * @throws \Box\Spout\Common\Exception\IOException If trying to create a new sheet and unable to open the sheet for writing
+     * @throws \Box\Spout\Writer\Exception\WriterException If unable to write data
+     */
+    public function addRowToCurrentWorksheet($dataRow, $style);
+
+    /**
+     * Closes the workbook and all its associated sheets.
+     * All the necessary files are written to disk and zipped together to create the ODS file.
+     * All the temporary files are then deleted.
+     *
+     * @param resource $finalFilePointer Pointer to the ODS that will be created
+     * @return void
+     */
+    public function close($finalFilePointer);
+}

src/Spout/Writer/Common/Internal/WorksheetInterface.php

@@ -0,0 +1,40 @@
+<?php
+
+namespace Box\Spout\Writer\Common\Internal;
+
+/**
+ * Interface WorksheetInterface
+ *
+ * @package Box\Spout\Writer\Common\Internal
+ */
+interface WorksheetInterface
+{
+    /**
+     * @return \Box\Spout\Writer\Common\Sheet The "external" sheet
+     */
+    public function getExternalSheet();
+
+    /**
+     * @return int The index of the last written row
+     */
+    public function getLastWrittenRowIndex();
+
+    /**
+     * Adds data to the worksheet.
+     *
+     * @param array $dataRow Array containing data to be written.
+     *          Example $dataRow = ['data1', 1234, null, '', 'data5'];
+     * @param \Box\Spout\Writer\Style\Style $style Style to be applied to the row. NULL means use default style.
+     * @return void
+     * @throws \Box\Spout\Common\Exception\IOException If the data cannot be written
+     * @throws \Box\Spout\Common\Exception\InvalidArgumentException If a cell value's type is not supported
+     */
+    public function addRow($dataRow, $style);
+
+    /**
+     * Closes the worksheet
+     *
+     * @return void
+     */
+    public function close();
+}

src/Spout/Writer/Common/Sheet.php

@@ -0,0 +1,156 @@
+<?php
+
+namespace Box\Spout\Writer\Common;
+
+use Box\Spout\Common\Helper\StringHelper;
+use Box\Spout\Writer\Exception\InvalidSheetNameException;
+
+/**
+ * Class Sheet
+ * External representation of a worksheet within a ODS file
+ *
+ * @package Box\Spout\Writer\Common
+ */
+class Sheet
+{
+    const DEFAULT_SHEET_NAME_PREFIX = 'Sheet';
+
+    /** Sheet name should not exceed 31 characters */
+    const MAX_LENGTH_SHEET_NAME = 31;
+
+    /** @var array Invalid characters that cannot be contained in the sheet name */
+    private static $INVALID_CHARACTERS_IN_SHEET_NAME = ['\\', '/', '?', '*', ':', '[', ']'];
+
+    /** @var array Associative array [SHEET_INDEX] => [SHEET_NAME] keeping track of sheets' name to enforce uniqueness */
+    protected static $SHEETS_NAME_USED = [];
+
+    /** @var int Index of the sheet, based on order of creation (zero-based) */
+    protected $index;
+
+    /** @var string Name of the sheet */
+    protected $name;
+
+    /** @var \Box\Spout\Common\Helper\StringHelper */
+    protected $stringHelper;
+
+    /**
+     * @param int $sheetIndex Index of the sheet, based on order of creation (zero-based)
+     */
+    public function __construct($sheetIndex)
+    {
+        $this->index = $sheetIndex;
+        $this->stringHelper = new StringHelper();
+        $this->setName(self::DEFAULT_SHEET_NAME_PREFIX . ($sheetIndex + 1));
+    }
+
+    /**
+     * @return int Index of the sheet, based on order of creation (zero-based)
+     */
+    public function getIndex()
+    {
+        return $this->index;
+    }
+
+    /**
+     * @return string Name of the sheet
+     */
+    public function getName()
+    {
+        return $this->name;
+    }
+
+    /**
+     * Sets the name of the sheet. Note that Excel has some restrictions on the name:
+     *  - it should not be blank
+     *  - it should not exceed 31 characters
+     *  - it should not contain these characters: \ / ? * : [ or ]
+     *  - it should be unique
+     *
+     * @param string $name Name of the sheet
+     * @return Sheet
+     * @throws \Box\Spout\Writer\Exception\InvalidSheetNameException If the sheet's name is invalid.
+     */
+    public function setName($name)
+    {
+        if (!$this->isNameValid($name)) {
+            $errorMessage = "The sheet's name is invalid. It did not meet at least one of these requirements:\n";
+            $errorMessage .= " - It should not be blank\n";
+            $errorMessage .= " - It should not exceed 31 characters\n";
+            $errorMessage .= " - It should not contain these characters: \\ / ? * : [ or ]\n";
+            $errorMessage .= " - It should be unique";
+            throw new InvalidSheetNameException($errorMessage);
+        }
+
+        $this->name = $name;
+        self::$SHEETS_NAME_USED[$this->index] = $name;
+
+        return $this;
+    }
+
+    /**
+     * Returns whether the given sheet's name is valid.
+     * @see Sheet::setName for validity rules.
+     *
+     * @param string $name
+     * @return bool TRUE if the name is valid, FALSE otherwise.
+     */
+    protected function isNameValid($name)
+    {
+        if (!is_string($name)) {
+            return false;
+        }
+
+        $nameLength = $this->stringHelper->getStringLength($name);
+
+        return (
+            $nameLength > 0 &&
+            $nameLength <= self::MAX_LENGTH_SHEET_NAME &&
+            !$this->doesContainInvalidCharacters($name) &&
+            $this->isNameUnique($name) &&
+            !$this->doesStartOrEndWithSingleQuote($name)
+        );
+    }
+
+    /**
+     * Returns whether the given name contains at least one invalid character.
+     * @see Sheet::$INVALID_CHARACTERS_IN_SHEET_NAME for the full list.
+     *
+     * @param string $name
+     * @return bool TRUE if the name contains invalid characters, FALSE otherwise.
+     */
+    protected function doesContainInvalidCharacters($name)
+    {
+        return (str_replace(self::$INVALID_CHARACTERS_IN_SHEET_NAME, '', $name) !== $name);
+    }
+
+    /**
+     * Returns whether the given name starts or ends with a single quote
+     *
+     * @param string $name
+     * @return bool TRUE if the name starts or ends with a single quote, FALSE otherwise.
+     */
+    protected function doesStartOrEndWithSingleQuote($name)
+    {
+        $startsWithSingleQuote = ($this->stringHelper->getCharFirstOccurrencePosition('\'', $name) === 0);
+        $endsWithSingleQuote = ($this->stringHelper->getCharLastOccurrencePosition('\'', $name) === ($this->stringHelper->getStringLength($name) - 1));
+
+        return ($startsWithSingleQuote || $endsWithSingleQuote);
+    }
+
+    /**
+     * Returns whether the given name is unique.
+     *
+     * @param string $name
+     * @return bool TRUE if the name is unique, FALSE otherwise.
+     */
+    protected function isNameUnique($name)
+    {
+        foreach (self::$SHEETS_NAME_USED as $sheetIndex => $sheetName) {
+            if ($sheetIndex !== $this->index && $sheetName === $name) {
+                return false;
+            }
+        }
+
+        return true;
+    }
+}