PathMatcher.php

Go to the documentation of this file.

<?php
 
namespace MediaWiki\Rest\PathTemplateMatcher;
 
class PathMatcher {
    private $treesByLength = [];
 
    public static function newFromCache( $data ) {
        $matcher = new self;
        $matcher->treesByLength = $data;
        return $matcher;
    }
 
    public function getCacheData() {
        return $this->treesByLength;
    }
 
    private function isParam( $part ) {
        $partLength = strlen( $part );
        return $partLength > 2 && $part[0] === '{' && $part[$partLength - 1] === '}';
    }
 
    private function getParamName( $part ) {
        if ( $this->isParam( $part ) ) {
            return substr( $part, 1, -1 );
        } else {
            return false;
        }
    }
 
    private function findConflict( $node, $parts, $index = 0 ) {
        if ( $index >= count( $parts ) ) {
            // If we reached the leaf node then a conflict is detected
            return $node;
        }
        $part = $parts[$index];
        $result = false;
 
        if ( $this->isParam( $part ) ) {
            foreach ( $node as $childNode ) {
                // Params and tree entries for trailing empty slashes ('=') do not conflict
                if ( !isset( $node['='] ) ) {
                    $result = $this->findConflict( $childNode, $parts, $index + 1 );
                    if ( $result !== false ) {
                        break;
                    }
                }
            }
        } else {
            if ( isset( $node["=$part"] ) ) {
                $result = $this->findConflict( $node["=$part"], $parts, $index + 1 );
            }
 
            // Trailing empty slashes (aka an empty $part) do not conflict with params
            if ( $result === false && isset( $node['*'] ) && $part !== '' ) {
                $result = $this->findConflict( $node['*'], $parts, $index + 1 );
            }
        }
        return $result;
    }
 
    public function add( $template, $userData ) {
        // This will produce an empty part before any leading slash and after any trailing slash
        $parts = explode( '/', $template );
        $length = count( $parts );
        if ( !isset( $this->treesByLength[$length] ) ) {
            $this->treesByLength[$length] = [];
        }
        $tree =& $this->treesByLength[$length];
 
        // Disallow empty path parts within the path (but not leading or trailing).
        for ( $i = 1; $i < $length - 1; $i++ ) {
            if ( $parts[$i] == '' ) {
                throw new PathSegmentException( $template, $userData );
            }
        }
 
        $conflict = $this->findConflict( $tree, $parts );
        if ( $conflict !== false ) {
            throw new PathConflict( $template, $userData, $conflict );
        }
 
        $params = [];
        foreach ( $parts as $index => $part ) {
            $paramName = $this->getParamName( $part );
            if ( $paramName !== false ) {
                $params[] = $paramName;
                $key = '*';
            } else {
                $key = "=$part";
            }
            if ( $index === $length - 1 ) {
                $tree[$key] = [
                    'template' => $template,
                    'paramNames' => $params,
                    'userData' => $userData
                ];
            } elseif ( !isset( $tree[$key] ) ) {
                $tree[$key] = [];
            }
            $tree =& $tree[$key];
        }
    }
 
    public function match( $path ) {
        $parts = explode( '/', $path );
        $length = count( $parts );
        if ( !isset( $this->treesByLength[$length] ) ) {
            return false;
        }
        $node = $this->treesByLength[$length];
 
        $paramValues = [];
        foreach ( $parts as $part ) {
            if ( isset( $node["=$part"] ) ) {
                $node = $node["=$part"];
            } elseif ( isset( $node['*'] ) ) {
                $node = $node['*'];
                $paramValues[] = $part;
            } else {
                return false;
            }
        }
 
        return [
            'params' => array_combine( $node['paramNames'], $paramValues ),
            'userData' => $node['userData']
        ];
    }
}