Parser_LinkHooks.php

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<?php
class Parser_LinkHooks extends Parser {
        const VERSION = '1.6.4';

        # Flags for Parser::setLinkHook
        # Also available as global constants from Defines.php
        const SLH_PATTERN = 1;

        # Constants needed for external link processing
        # Everything except bracket, space, or control characters
        const EXT_LINK_URL_CLASS = '[^][<>"\\x00-\\x20\\x7F]';
        const EXT_IMAGE_REGEX = '/^(http:\/\/|https:\/\/)([^][<>"\\x00-\\x20\\x7F]+)
                \\/([A-Za-z0-9_.,~%\\-+&;#*?!=()@\\x80-\\xFF]+)\\.((?i)gif|png|jpg|jpeg)$/Sx';

        # Persistent:
        var $mLinkHooks;

        public function __construct( $conf = array() ) {
                parent::__construct( $conf );
                $this->mLinkHooks = array();
        }

        function firstCallInit() {
                parent::__construct();
                if ( !$this->mFirstCall ) {
                        return;
                }
                $this->mFirstCall = false;

                wfProfileIn( __METHOD__ );

                $this->setHook( 'pre', array( $this, 'renderPreTag' ) );
                CoreParserFunctions::register( $this );
                CoreLinkFunctions::register( $this );
                $this->initialiseVariables();

                wfRunHooks( 'ParserFirstCallInit', array( &$this ) );
                wfProfileOut( __METHOD__ );
        }

        public function setLinkHook( $ns, $callback, $flags = 0 ) {
                if( $flags & SLH_PATTERN && !is_string($ns) )
                        throw new MWException( __METHOD__ . '() expecting a regex string pattern.' );
                elseif( $flags | ~SLH_PATTERN && !is_int( $ns ) )
                        throw new MWException( __METHOD__ . '() expecting a namespace index.' );
                $oldVal = isset( $this->mLinkHooks[$ns] ) ? $this->mLinkHooks[$ns][0] : null;
                $this->mLinkHooks[$ns] = array( $callback, $flags );
                return $oldVal;
        }

        function getLinkHooks() {
                return array_keys( $this->mLinkHooks );
        }

        function replaceInternalLinks2( &$s ) {
                wfProfileIn( __METHOD__ );

                wfProfileIn( __METHOD__ . '-setup' );
                static $tc = false, $titleRegex; //$e1, $e1_img;
                if( !$tc ) {
                        # the % is needed to support urlencoded titles as well
                        $tc = Title::legalChars() . '#%';
                        # Match a link having the form [[namespace:link|alternate]]trail
                        //$e1 = "/^([{$tc}]+)(?:\\|(.+?))?]](.*)\$/sD";
                        # Match cases where there is no "]]", which might still be images
                        //$e1_img = "/^([{$tc}]+)\\|(.*)\$/sD";
                        # Match a valid plain title
                        $titleRegex = "/^([{$tc}]+)$/sD";
                }

                $holders = new LinkHolderArray( $this );

                if( is_null( $this->mTitle ) ) {
                        wfProfileOut( __METHOD__ . '-setup' );
                        wfProfileOut( __METHOD__ );
                        throw new MWException( __METHOD__ . ": \$this->mTitle is null\n" );
                }

                wfProfileOut( __METHOD__ . '-setup' );

                $offset = 0;
                $offsetStack = array();
                $markers = new LinkMarkerReplacer( $this, $holders, array( &$this, 'replaceInternalLinksCallback' ) );
                while( true ) {
                        $startBracketOffset = strpos( $s, '[[', $offset );
                        $endBracketOffset   = strpos( $s, ']]', $offset );
                        # Finish when there are no more brackets
                        if( $startBracketOffset === false && $endBracketOffset === false ) break;
                        # Determine if the bracket is a starting or ending bracket
                        # When we find both, use the first one
                        elseif( $startBracketOffset !== false && $endBracketOffset !== false )
                                $isStart = $startBracketOffset <= $endBracketOffset;
                        # When we only found one, check which it is
                        else $isStart = $startBracketOffset !== false;
                        $bracketOffset = $isStart ? $startBracketOffset : $endBracketOffset;
                        if( $isStart ) {
                                # Just push our current offset in the string onto the stack
                                $offsetStack[] = $startBracketOffset;
                        } else {
                                # Pop the start pos for our current link zone off the stack
                                $startBracketOffset = array_pop( $offsetStack );
                                # Just to clean up the code, lets place offsets on the outer ends
                                $endBracketOffset += 2;

                                # Only do logic if we actually have a opening bracket for this
                                if( isset( $startBracketOffset ) ) {
                                        # Extract text inside the link
                                        @list( $titleText, $paramText ) = explode( '|',
                                                substr( $s, $startBracketOffset + 2, $endBracketOffset - $startBracketOffset - 4 ), 2 );
                                        # Create markers only for valid links
                                        if( preg_match( $titleRegex, $titleText ) ) {
                                                # Store the text for the marker
                                                $marker = $markers->addMarker( $titleText, $paramText );
                                                # Replace the current link with the marker
                                                $s = substr( $s, 0, $startBracketOffset ) .
                                                        $marker .
                                                        substr( $s, $endBracketOffset );
                                                # We have modified $s, because of this we need to set the
                                                # offset manually since the end position is different now
                                                $offset = $startBracketOffset+strlen( $marker );
                                                continue;
                                        }
                                        # ToDo: Some LinkHooks may allow recursive links inside of
                                        # the link text, create a regex that also matches our
                                        # <!-- LINKMARKER ### --> sequence in titles
                                        # ToDO: Some LinkHooks use patterns rather than namespaces
                                        # these need to be tested at this point here
                                }
                        }
                        # Bump our offset to after our current bracket
                        $offset = $bracketOffset+2;
                }

                # Now expand our tree
                wfProfileIn( __METHOD__ . '-expand' );
                $s = $markers->expand( $s );
                wfProfileOut( __METHOD__ . '-expand' );

                wfProfileOut( __METHOD__ );
                return $holders;
        }

        function replaceInternalLinksCallback( $parser, $holders, $markers, $titleText, $paramText ) {
                wfProfileIn( __METHOD__ );
                $wt = isset( $paramText ) ? "[[$titleText|$paramText]]" : "[[$titleText]]";
                wfProfileIn( __METHOD__ . "-misc" );

                # Don't allow internal links to pages containing
                # PROTO: where PROTO is a valid URL protocol; these
                # should be external links.
                if( preg_match( '/^\b(?i:' . wfUrlProtocols() . ')/', $titleText ) ) {
                        wfProfileOut( __METHOD__ . "-misc" );
                        wfProfileOut( __METHOD__ );
                        return $wt;
                }

                # Make subpage if necessary
                if( $this->areSubpagesAllowed() ) {
                        $titleText = $this->maybeDoSubpageLink( $titleText, $paramText );
                }

                # Check for a leading colon and strip it if it is there
                $leadingColon = $titleText[0] == ':';
                if( $leadingColon ) $titleText = substr( $titleText, 1 );

                wfProfileOut( __METHOD__ . "-misc" );
                # Make title object
                wfProfileIn( __METHOD__ . "-title" );
                $title = Title::newFromText( $this->mStripState->unstripNoWiki( $titleText ) );
                if( !$title ) {
                        wfProfileOut( __METHOD__ . "-title" );
                        wfProfileOut( __METHOD__ );
                        return $wt;
                }
                $ns = $title->getNamespace();
                wfProfileOut( __METHOD__ . "-title" );

                # Default for Namespaces is a default link
                # ToDo: Default for patterns is plain wikitext
                $return = true;
                if( isset( $this->mLinkHooks[$ns] ) ) {
                        list( $callback, $flags ) = $this->mLinkHooks[$ns];
                        if( $flags & SLH_PATTERN ) {
                                $args = array( $parser, $holders, $markers, $titleText, &$paramText, &$leadingColon );
                        } else {
                                $args = array( $parser, $holders, $markers, $title, $titleText, &$paramText, &$leadingColon );
                        }
                        # Workaround for PHP bug 35229 and similar
                        if ( !is_callable( $callback ) ) {
                                throw new MWException( "Tag hook for namespace $ns is not callable\n" );
                        }
                        $return = call_user_func_array( $callback, $args );
                }
                if( $return === true ) {
                        # True (treat as plain link) was returned, call the defaultLinkHook
                        $return = CoreLinkFunctions::defaultLinkHook( $parser, $holders, $markers, $title,
                                $titleText, $paramText, $leadingColon );
                }
                if( $return === false ) {
                        # False (no link) was returned, output plain wikitext
                        # Build it again as the hook is allowed to modify $paramText
                        $return = isset( $paramText ) ? "[[$titleText|$paramText]]" : "[[$titleText]]";
                }
                # Content was returned, return it
                wfProfileOut( __METHOD__ );
                return $return;
        }

}

class LinkMarkerReplacer {

        protected $markers, $nextId, $parser, $holders, $callback;

        function __construct( $parser, $holders, $callback ) {
                $this->nextId   = 0;
                $this->markers  = array();
                $this->parser   = $parser;
                $this->holders  = $holders;
                $this->callback = $callback;
        }

        function addMarker( $titleText, $paramText ) {
                $id = $this->nextId++;
                $this->markers[$id] = array( $titleText, $paramText );
                return "<!-- LINKMARKER $id -->";
        }

        function findMarker( $string ) {
                return (bool) preg_match( '/<!-- LINKMARKER [0-9]+ -->/', $string );
        }

        function expand( $string ) {
                return StringUtils::delimiterReplaceCallback( "<!-- LINKMARKER ", " -->", array( &$this, 'callback' ), $string );
        }

        function callback( $m ) {
                $id = intval( $m[1] );
                if( !array_key_exists( $id, $this->markers ) ) return $m[0];
                $args = $this->markers[$id];
                array_unshift( $args, $this );
                array_unshift( $args, $this->holders );
                array_unshift( $args, $this->parser );
                return call_user_func_array( $this->callback, $args );
        }
}