templates/TEMPLATE_NAME/html/renderer/head.php

<?php
/**
 * @package     Joomla.Platform
 * @subpackage  Document
 *
 * @copyright   Copyright (C) 2005 - 2015 Open Source Matters, Inc. All rights reserved.
 * @license     GNU General Public License version 2 or later; see LICENSE
 */

defined('JPATH_PLATFORM') or die;

/**
 * JDocument head renderer
 *
 * @since  11.1
 */
class JDocumentRendererHead extends JDocumentRenderer
{
    /**
     * Renders the document head and returns the results as a string
     *
     * @param   string  $head     (unused)
     * @param   array   $params   Associative array of values
     * @param   string  $content  The script
     *
     * @return  string  The output of the script
     *
     * @since   11.1
     *
     * @note    Unused arguments are retained to preserve backward compatibility.
     */
    public function render($head, $params = array(), $content = null)
    {

        if ($params['name'] == 'head')
        {
            return $this->fetchHead($this->_doc);
        }
        elseif ($params['name'] == 'footer')
        {
            return $this->fetchFooter($this->_doc);
        }
    }

    /**
     * Generates the head HTML and return the results as a string
     *
     * @param   JDocument  $document  The document for which the head will be created
     *
     * @return  string  The head hTML
     *
     * @since   11.1
     */
    public function fetchHead($document)
    {
        // Convert the tagids to titles
        if (isset($document->_metaTags['standard']['tags']))
        {
            $tagsHelper = new JHelperTags;
            $document->_metaTags['standard']['tags'] = implode(', ', $tagsHelper->getTagNames($document->_metaTags['standard']['tags']));
        }

        // Trigger the onBeforeCompileHead event
        $app = JFactory::getApplication();
        $app->triggerEvent('onBeforeCompileHead');

        // Get line endings
        $lnEnd = $document->_getLineEnd();
        $tab = $document->_getTab();
        $tagEnd = ' />';
        $buffer = '';

        // Generate charset when using HTML5 (should happen first)
        if ($document->isHtml5())
        {
            $buffer .= $tab . '<meta charset="' . $document->getCharset() . '" />' . $lnEnd;
        }

        // Generate base tag (need to happen early)
        $base = $document->getBase();

        if (!empty($base))
        {
            $buffer .= $tab . '<base href="' . $document->getBase() . '" />' . $lnEnd;
        }

        // Generate META tags (needs to happen as early as possible in the head)
        foreach ($document->_metaTags as $type => $tag)
        {
            foreach ($tag as $name => $content)
            {
                if ($type == 'http-equiv' && !($document->isHtml5() && $name == 'content-type'))
                {
                    $buffer .= $tab . '<meta http-equiv="' . $name . '" content="' . htmlspecialchars($content) . '" />' . $lnEnd;
                }
                elseif ($type == 'standard' && !empty($content))
                {
                    $buffer .= $tab . '<meta name="' . $name . '" content="' . htmlspecialchars($content) . '" />' . $lnEnd;
                }
            }
        }

        // Don't add empty descriptions
        $documentDescription = $document->getDescription();

        if ($documentDescription)
        {
            $buffer .= $tab . '<meta name="description" content="' . htmlspecialchars($documentDescription) . '" />' . $lnEnd;
        }

        // Don't add empty generators
        $generator = $document->getGenerator();

        if ($generator)
        {
            $buffer .= $tab . '<meta name="generator" content="' . htmlspecialchars($generator) . '" />' . $lnEnd;
        }

        $buffer .= $tab . '<title>' . htmlspecialchars($document->getTitle(), ENT_COMPAT, 'UTF-8') . '</title>' . $lnEnd;

        // Generate link declarations
        foreach ($document->_links as $link => $linkAtrr)
        {
            $buffer .= $tab . '<link href="' . $link . '" ' . $linkAtrr['relType'] . '="' . $linkAtrr['relation'] . '"';

            if ($temp = JArrayHelper::toString($linkAtrr['attribs']))
            {
                $buffer .= ' ' . $temp;
            }

            $buffer .= ' />' . $lnEnd;
        }

        // Generate stylesheet links
        foreach ($document->_styleSheets as $strSrc => $strAttr)
        {
            $buffer .= $tab . '<link rel="stylesheet" href="' . $strSrc . '"';

            if (!is_null($strAttr['mime']) && (!$document->isHtml5() || $strAttr['mime'] != 'text/css'))
            {
                $buffer .= ' type="' . $strAttr['mime'] . '"';
            }

            if (!is_null($strAttr['media']))
            {
                $buffer .= ' media="' . $strAttr['media'] . '"';
            }

            if ($temp = JArrayHelper::toString($strAttr['attribs']))
            {
                $buffer .= ' ' . $temp;
            }

            $buffer .= $tagEnd . $lnEnd;
        }

        // Generate stylesheet declarations
        foreach ($document->_style as $type => $content)
        {
            $buffer .= $tab . '<style type="' . $type . '">' . $lnEnd;

            // This is for full XHTML support.
            if ($document->_mime != 'text/html')
            {
                $buffer .= $tab . $tab . '/*<![CDATA[*/' . $lnEnd;
            }

            $buffer .= $content . $lnEnd;

            // See above note
            if ($document->_mime != 'text/html')
            {
                $buffer .= $tab . $tab . '/*]]>*/' . $lnEnd;
            }

            $buffer .= $tab . '</style>' . $lnEnd;
        }

        foreach ($document->_custom as $custom)
        {
            $buffer .= $tab . $custom . $lnEnd;
        }

        return $buffer;
    }

    /**
     * Generates the head HTML and return the results as a string
     *
     * @param   JDocument  $document  The document for which the head will be created
     *
     * @return  string  The head hTML
     *
     * @since   11.1
     */
    public function fetchFooter($document)
    {
        // Convert the tagids to titles
        if (isset($document->_metaTags['standard']['tags']))
        {
            $tagsHelper = new JHelperTags;
            $document->_metaTags['standard']['tags'] = implode(', ', $tagsHelper->getTagNames($document->_metaTags['standard']['tags']));
        }

        // Trigger the onBeforeCompileHead event
        $app = JFactory::getApplication();
        $app->triggerEvent('onBeforeCompileHead');

        // Get line endings
        $lnEnd = $document->_getLineEnd();
        $tab = $document->_getTab();
        $tagEnd = ' />';
        $buffer = '';

        // Generate script file links
        foreach ($document->_scripts as $strSrc => $strAttr)
        {
            $buffer .= $tab . '<script src="' . $strSrc . '"';
            $defaultMimes = array(
                'text/javascript', 'application/javascript', 'text/x-javascript', 'application/x-javascript'
            );

            if (!is_null($strAttr['mime']) && (!$document->isHtml5() || !in_array($strAttr['mime'], $defaultMimes)))
            {
                $buffer .= ' type="' . $strAttr['mime'] . '"';
            }

            if ($strAttr['defer'])
            {
                $buffer .= ' defer="defer"';
            }

            if ($strAttr['async'])
            {
                $buffer .= ' async="async"';
            }

            $buffer .= '></script>' . $lnEnd;
        }

        // Generate script declarations
        foreach ($document->_script as $type => $content)
        {
            $buffer .= $tab . '<script type="' . $type . '">' . $lnEnd;

            // This is for full XHTML support.
            if ($document->_mime != 'text/html')
            {
                $buffer .= $tab . $tab . '//<![CDATA[' . $lnEnd;
            }

            $buffer .= $content . $lnEnd;

            // See above note
            if ($document->_mime != 'text/html')
            {
                $buffer .= $tab . $tab . '//]]>' . $lnEnd;
            }

            $buffer .= $tab . '</script>' . $lnEnd;
        }

        // Generate script language declarations.
        if (count(JText::script()))
        {
            $buffer .= $tab . '<script type="text/javascript">' . $lnEnd;

            if ($document->_mime != 'text/html')
            {
                $buffer .= $tab . $tab . '//<![CDATA[' . $lnEnd;
            }

            $buffer .= $tab . $tab . '(function() {' . $lnEnd;
            $buffer .= $tab . $tab . $tab . 'Joomla.JText.load(' . json_encode(JText::script()) . ');' . $lnEnd;
            $buffer .= $tab . $tab . '})();' . $lnEnd;

            if ($document->_mime != 'text/html')
            {
                $buffer .= $tab . $tab . '//]]>' . $lnEnd;
            }

            $buffer .= $tab . '</script>' . $lnEnd;
        }

        foreach ($document->_custom as $custom)
        {
            $buffer .= $tab . $custom . $lnEnd;
        }

        return $buffer;
    }
}