arthurkushman / querypath

src/CSS/DOMTraverser/Util.php

<?php
/**
 * @file
 *
 * Utilities for DOM traversal.
 */

namespace QueryPath\CSS\DOMTraverser;

use \QueryPath\CSS\EventHandler;

/**
 * Utilities for DOM Traversal.
 */
class Util
{
    /**
     * Check whether the given DOMElement has the given attribute.
     *
     * @param $node
     * @param $name
     * @param null $value

Are you sure the doc-type for parameter $value is correct as it would always require null to be passed?

     * @param int $operation
     * @return bool
     */
    public static function matchesAttribute($node, $name, $value = NULL, $operation = EventHandler::IS_EXACTLY): bool
    {
        if (!$node->hasAttribute($name)) {
            return false;
        }

        if (NULL === $value) {

The condition NULL === $value is always true.

            return true;
        }

        return self::matchesAttributeValue($value, $node->getAttribute($name), $operation);
    }

    /**
     * Check whether the given DOMElement has the given namespaced attribute.
     */
    public static function matchesAttributeNS($node, $name, $nsuri, $value = NULL, $operation = EventHandler::IS_EXACTLY)
    {
        if (!$node->hasAttributeNS($nsuri, $name)) {
            return false;
        }

        if (is_null($value)) {
            return true;
        }

        return self::matchesAttributeValue($value, $node->getAttributeNS($nsuri, $name), $operation);
    }

    /**
     * Check for attr value matches based on an operation.
     */
    public static function matchesAttributeValue($needle, $haystack, $operation): bool
    {

        if (strlen($haystack) < strlen($needle)) {
            return false;
        }

        // According to the spec:
        // "The case-sensitivity of attribute names in selectors depends on the document language."
        // (6.3.2)
        // To which I say, "huh?". We assume case sensitivity.
        switch ($operation) {
            case EventHandler::IS_EXACTLY:
                return $needle == $haystack;
            case EventHandler::CONTAINS_WITH_SPACE:
                // XXX: This needs testing!
                return preg_match('/\b/', $haystack) == 1;
            //return in_array($needle, explode(' ', $haystack));
            case EventHandler::CONTAINS_WITH_HYPHEN:
                return in_array($needle, explode('-', $haystack));
            case EventHandler::CONTAINS_IN_STRING:
                return strpos($haystack, $needle) !== false;
            case EventHandler::BEGINS_WITH:
                return strpos($haystack, $needle) === 0;
            case EventHandler::ENDS_WITH:
                //return strrpos($haystack, $needle) === strlen($needle) - 1;
                return preg_match('/' . $needle . '$/', $haystack) == 1;
        }

        return false; // Shouldn't be able to get here.
    }

    /**
     * Remove leading and trailing quotes.
     */
    public static function removeQuotes(string $str)
    {
        $f = mb_substr($str, 0, 1);
        $l = mb_substr($str, -1);
        if ($f === $l && ($f === '"' || $f === "'")) {
            $str = mb_substr($str, 1, -1);
        }

        return $str;
    }

    /**
     * Parse an an+b rule for CSS pseudo-classes.
     *
     * Invalid rules return `array(0, 0)`. This is per the spec.
     *
     * @param $rule
     *  Some rule in the an+b format.
     * @retval array
     *  `array($aVal, $bVal)` of the two values.
     * @return array
     */
    public static function parseAnB($rule): array
    {
        if ($rule === 'even') {
            return [2, 0];
        }

        if ($rule === 'odd') {
            return [2, 1];
        }

        if ($rule === 'n') {
            return [1, 0];
        }

        if (is_numeric($rule)) {
            return [0, (int)$rule];
        }

        $regex = '/^\s*([+\-]?[0-9]*)n\s*([+\-]?)\s*([0-9]*)\s*$/';
        $matches = [];
        $res = preg_match($regex, $rule, $matches);

        // If it doesn't parse, return 0, 0.
        if (!$res) {
            return [0, 0];
        }

        $aVal = $matches[1] ?? 1;
        if ($aVal === '-') {
            $aVal = -1;
        } else {
            $aVal = (int)$aVal;
        }

        $bVal = 0;
        if (isset($matches[3])) {
            $bVal = (int)$matches[3];
            if (isset($matches[2]) && $matches[2] === '-') {
                $bVal *= -1;
            }
        }

        return [$aVal, $bVal];
    }

}