doc.silverstripe.org/sapphire/dev/CSSContentParser.php
2011-04-10 21:53:26 +00:00

110 lines
3.3 KiB
PHP

<?php
/**
* CSSContentParser enables parsing & assertion running of HTML content via CSS selectors.
*
* It works by converting the content to XHTML using tidy, rewriting the CSS selectors as XPath queries, and executing
* those using SimpeXML.
*
* It was built to facilitate testing using PHPUnit and contains a number of assert methods that will throw PHPUnit
* assertion exception when applicable.
*
* Tries to use the PHP Tidy extension (http://php.net/tidy),
* and falls back to the "tidy" CLI tool. If none of those exists,
* the string is parsed directly without sanitization.
*
* @package sapphire
* @subpackage core
*/
class CSSContentParser extends Object {
protected $simpleXML = null;
function __construct($content) {
if(extension_loaded('tidy')) {
// using the tiny php extension
$tidy = new Tidy();
$tidy->parseString(
$content,
array(
'output-xhtml' => true,
'numeric-entities' => true,
'wrap' => 99999, // We need this to be consistent for functional test string comparisons
),
'utf8'
);
$tidy->cleanRepair();
$tidy = str_replace('xmlns="http://www.w3.org/1999/xhtml"','',$tidy);
$tidy = str_replace('&#160;','',$tidy);
} elseif(@shell_exec('which tidy')) {
// using tiny through cli
$CLI_content = escapeshellarg($content);
$tidy = `echo $CLI_content | tidy -n -q -utf8 -asxhtml 2> /dev/null`;
$tidy = str_replace('xmlns="http://www.w3.org/1999/xhtml"','',$tidy);
$tidy = str_replace('&#160;','',$tidy);
} else {
// no tidy library found, hence no sanitizing
$tidy = $content;
}
$this->simpleXML = @simplexml_load_string($tidy, 'SimpleXMLElement', LIBXML_NOWARNING);
if(!$this->simpleXML) {
throw new Exception('CSSContentParser::__construct(): Could not parse content. Please check the PHP extension tidy is installed.');
}
parent::__construct();
}
/**
* Returns a number of SimpleXML elements that match the given CSS selector.
* Currently the selector engine only supports querying by tag, id, and class.
* See {@link getByXpath()} for a more direct selector syntax.
*
* @param String $selector
* @return SimpleXMLElement
*/
function getBySelector($selector) {
$xpath = $this->selector2xpath($selector);
return $this->getByXpath($xpath);
}
/**
* Allows querying the content through XPATH selectors.
*
* @param String $xpath SimpleXML compatible XPATH statement
* @return SimpleXMLElement|false
*/
function getByXpath($xpath) {
return $this->simpleXML->xpath($xpath);
}
/**
* Converts a CSS selector into an equivalent xpath expression.
* Currently the selector engine only supports querying by tag, id, and class.
*
* @param String $selector See {@link getBySelector()}
* @return String XPath expression
*/
function selector2xpath($selector) {
$parts = preg_split('/\\s+/', $selector);
$xpath = "";
foreach($parts as $part) {
if(preg_match('/^([A-Za-z][A-Za-z0-9]*)/', $part, $matches)) {
$xpath .= "//$matches[1]";
} else {
$xpath .= "//*";
}
$xfilters = array();
if(preg_match('/#([^#.\[]+)/', $part, $matches)) {
$xfilters[] = "@id='$matches[1]'";
}
if(preg_match('/\.([^#.\[]+)/', $part, $matches)) {
$xfilters[] = "contains(@class,'$matches[1]')";
}
if($xfilters) $xpath .= '[' . implode(',', $xfilters) . ']';
}
return $xpath;
}
}