functions.php

<?php

/* Copyright (c) 2019 Geert Bergman (geert@scrivo.nl), highlight.php
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice,
 *    this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright notice,
 *    this list of conditions and the following disclaimer in the documentation
 *    and/or other materials provided with the distribution.
 * 3. Neither the name of "highlight.js", "highlight.php", nor the names of its
 *    contributors may be used to endorse or promote products derived from this
 *    software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

namespace HighlightUtilities;

/**
 * Convert the HTML generated by Highlighter and split it up into an array of lines.
 *
 * @api
 *
 * @since 9.15.6.1
 *
 * @param string $html An HTML string generated by `Highlighter::highlight()`
 *
 * @throws \RuntimeException         when the DOM extension is not available
 * @throws \UnexpectedValueException when the given HTML could not be parsed
 *
 * @return string[]|false An array of lines of code as strings. False if an error occurred in splitting up by lines
 */
function splitCodeIntoArray($html)
{
    if (!extension_loaded("dom")) {
        throw new \RuntimeException("The DOM extension is not loaded but is required.");
    }

    $dom = new \DOMDocument();

    if (!$dom->loadHTML($html)) {
        throw new \UnexpectedValueException("The given HTML could not be parsed correctly.");
    }

    $spans = $dom->getElementsByTagName("span");

    /** @var \DOMElement $span */
    foreach ($spans as $span) {
        $classes = $span->getAttribute("class");
        $renderedSpan = $dom->saveHTML($span);

        if (preg_match('/\R/', $renderedSpan)) {
            $finished = preg_replace(
                '/\R/',
                sprintf('</span>%s<span class="%s">', PHP_EOL, $classes),
                $renderedSpan
            );
            $html = str_replace($renderedSpan, $finished, $html);
        }
    }

    return preg_split('/\R/', $html);
}