_getTab() returns spaces

Question

Why does the following code return two spaces instead of one tab? How can I change this setting easily?

$document = JFactory::getDocument();
$tab = $document->_getTab();

reference

Answer 1

Two spaces are hard coded in protected static function createDocument() located inside libraries/joomla/factory.php:

$attributes = array(
        'charset' => 'utf-8',
        'lineend' => 'unix',
        'tab' => '  ',
        'language' => $lang->getTag(),
        'direction' => $lang->isRTL() ? 'rtl' : 'ltr',
        'mediaversion' => $version->getMediaVersion()
    );

which overrides previous class property declaration of \11 in libraries/joomla/document/document.php and all rows in the head section become indented with 2 spaces.

Answer 2

If you read the method documentation, it is doing exactly what its supposed to. Which is return the system default for the number of spaces a keyboard tab event contains.

Below is the method as taken from JDocument class:

/**
 * Returns a string containing the unit for indenting HTML
 *
 * @return  string
 *
 * @since   11.1
 */
public function _getTab()
{
    return $this->_tab;
}

And the class property for $_tab:

/**
 * Tab string
 *
 * @var    string
 * @since  11.1
 */
public $_tab = "\11";

Using the above and referencing the PHP Documents for Escape Sequences in text we see a reference to exact string:

\11
might be a back reference, or another way of writing a tab

You can visit the below link for more info, but the method in question returns the PHP escape sequence for a tab.

http://php.net/manual/en/regexp.reference.escape.php