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<?php
namespace League\HTMLToMarkdown\Converter;
use League\HTMLToMarkdown\ElementInterface;
class ParagraphConverter implements ConverterInterface
{
/**
* @param ElementInterface $element
*
* @return string
*/
public function convert(ElementInterface $element)
{
$value = $element->getValue();
$markdown = '';
$lines = preg_split('/\r\n|\r|\n/', $value);
foreach ($lines as $line) {
/*
* Some special characters need to be escaped based on the position that they appear
* The following function will deal with those special cases.
*/
$markdown .= $this->escapeSpecialCharacters($line);
$markdown .= "\n";
}
return trim($markdown) !== '' ? rtrim($markdown) . "\n\n" : '';
}
/**
* @return string[]
*/
public function getSupportedTags()
{
return array('p');
}
/**
* @param string $line
*
* @return string
*/
private function escapeSpecialCharacters($line)
{
$line = $this->escapeFirstCharacters($line);
$line = $this->escapeOtherCharacters($line);
$line = $this->escapeOtherCharactersRegex($line);
return $line;
}
/**
* @param string $line
*
* @return string
*/
private function escapeFirstCharacters($line)
{
$escapable = array(
'>',
'- ',
'+ ',
'--',
'~~~',
'---',
'- - -'
);
foreach ($escapable as $i) {
if (strpos(ltrim($line), $i) === 0) {
// Found a character that must be escaped, adding a backslash before
return '\\' . ltrim($line);
}
}
return $line;
}
/**
* @param string $line
*
* @return string
*/
private function escapeOtherCharacters($line)
{
$escapable = array(
'<!--'
);
foreach ($escapable as $i) {
if (strpos($line, $i) !== false) {
// Found an escapable character, escaping it
$line = substr_replace($line, '\\', strpos($line, $i), 0);
}
}
return $line;
}
/**
* @param string $line
*
* @return string
*/
private function escapeOtherCharactersRegex($line)
{
$regExs = array(
// Match numbers ending on ')' or '.' that are at the beginning of the line.
// They will be escaped if immediately followed by a space or newline.
'/^[0-9]+(?=(\)|\.)( |$))/'
);
foreach ($regExs as $i) {
if (preg_match($i, $line, $match)) {
// Matched an escapable character, adding a backslash on the string before the offending character
$line = substr_replace($line, '\\', strlen($match[0]), 0);
}
}
return $line;
}
}
|
