<?php
/**
* @package s9e\TextFormatter
* @copyright Copyright (c) 2010-2021 The s9e authors
* @license http://www.opensource.org/licenses/mit-license.php The MIT License
*/
namespace s9e\TextFormatter;
use DOMDocument;
use InvalidArgumentException;
abstract class Renderer
{
/**
* @var array Associative array of [paramName => paramValue]
*/
protected $params = [];
/**
* @var string Saved locale
*/
protected $savedLocale = '0';
/**
* Create a return a new DOMDocument loaded with given XML
*
* @param string $xml Source XML
* @return DOMDocument
*/
protected function loadXML($xml)
{
$this->checkUnsupported($xml);
// Activate small nodes allocation and relax LibXML's hardcoded limits if applicable. Limits
// on tags can be set during configuration
$flags = (LIBXML_VERSION >= 20700) ? LIBXML_COMPACT | LIBXML_PARSEHUGE : 0;
$useErrors = libxml_use_internal_errors(true);
$dom = new DOMDocument;
$success = $dom->loadXML($xml, $flags);
libxml_use_internal_errors($useErrors);
if (!$success)
{
throw new InvalidArgumentException('Cannot load XML: ' . libxml_get_last_error()->message);
}
return $dom;
}
/**
* Render an intermediate representation
*
* @param string $xml Intermediate representation
* @return string Rendered result
*/
public function render($xml)
{
if (substr($xml, 0, 3) === '<t>' && substr($xml, -4) === '</t>')
{
return $this->renderPlainText($xml);
}
else
{
return $this->renderRichText(preg_replace('(<[eis]>[^<]*</[eis]>)', '', $xml));
}
}
/**
* Render an intermediate representation of plain text
*
* @param string $xml Intermediate representation
* @return string Rendered result
*/
protected function renderPlainText($xml)
{
// Remove the <t> and </t> tags
$html = substr($xml, 3, -4);
// Replace all <br/> with <br>
$html = str_replace('<br/>', '<br>', $html);
// Decode encoded characters from the Supplementary Multilingual Plane
$html = $this->decodeSMP($html);
return $html;
}
/**
* Render an intermediate representation of rich text
*
* @param string $xml Intermediate representation
* @return string Rendered result
*/
abstract protected function renderRichText($xml);
/**
* Get the value of a parameter
*
* @param string $paramName
* @return string
*/
public function getParameter($paramName)
{
return $this->params[$paramName] ?? '';
}
/**
* Get the values of all parameters
*
* @return array Associative array of parameter names and values
*/
public function getParameters()
{
return $this->params;
}
/**
* Set the value of a parameter from the stylesheet
*
* @param string $paramName Parameter name
* @param mixed $paramValue Parameter's value
* @return void
*/
public function setParameter($paramName, $paramValue)
{
$this->params[$paramName] = (string) $paramValue;
}
/**
* Set the values of several parameters from the stylesheet
*
* @param array $params Associative array of [parameter name => parameter value]
* @return void
*/
public function setParameters(array $params)
{
foreach ($params as $paramName => $paramValue)
{
$this->setParameter($paramName, $paramValue);
}
}
/**
* Test for the presence of unsupported XML and throw an exception if found
*
* @param string $xml XML
* @return void
*/
protected function checkUnsupported($xml)
{
if (preg_match('((?<=<)[!?])', $xml, $m))
{
$errors = [
'!' => 'DTDs, CDATA nodes and comments are not allowed',
'?' => 'Processing instructions are not allowed'
];
throw new InvalidArgumentException($errors[$m[0]]);
}
}
/**
* Decode encoded characters from the Supplementary Multilingual Plane
*
* @param string $str Encoded string
* @return string Decoded string
*/
protected function decodeSMP($str)
{
if (strpos($str, '&#') === false)
{
return $str;
}
return preg_replace_callback('(&#(?:x[0-9A-Fa-f]+|[0-9]+);)', __CLASS__ . '::decodeEntity', $str);
}
/**
* Decode a matched SGML entity
*
* @param string[] $m Captures from PCRE
* @return string Decoded entity
*/
protected static function decodeEntity(array $m)
{
return htmlspecialchars(html_entity_decode($m[0], ENT_QUOTES, 'UTF-8'), ENT_COMPAT);
}
/**
* Restore the original locale
*/
protected function restoreLocale(): void
{
if ($this->savedLocale !== 'C')
{
setlocale(LC_NUMERIC, $this->savedLocale);
}
}
/**
* Temporarily set the locale to C
*/
protected function setLocale(): void
{
$this->savedLocale = setlocale(LC_NUMERIC, '0');
if ($this->savedLocale !== 'C')
{
setlocale(LC_NUMERIC, 'C');
}
}
}