wikimedia/mediawiki-core

<?php

namespace MediaWiki\Registration;

use Exception;
use HttpStatus;
use MediaWiki\Html\TemplateParser;
use Wikimedia\ObjectCache\EmptyBagOStuff;

/**
 * Thrown when ExtensionRegistry cannot open the extension.json or skin.json file.
 *
 * We handle this case specially, because it is one of the more
 * common errors a new MW sysadmin is likely to encounter and we
 * want their initial experience to be good. wfLoadExtension()
 * generally happens before MWExceptionRenderer gets installed
 * so we cannot use that.
 *
 * @ingroup ExtensionRegistry
 * @internal
 */
class MissingExtensionException extends Exception {
    private bool $isSkin;
    private string $extName = 'unknown';
    private string $path;
    private string $error;

    /**
     * @param string $path Path of file that cannot be read
     * @param string $error Text of error mtime gave
     */
    public function __construct( string $path, string $error ) {
        $this->isSkin = str_ends_with( $path, "/skin.json" );
        $m = [];
        preg_match( "!/([^/]*)/[^/]*.json$!", $path, $m );
        if ( $m ) {
            $this->extName = $m[1];
        }
        $this->path = $path;
        $this->error = $error;

        parent::__construct( "Error Loading extension. Unable to open file $path: $error" );
    }

    /**
     * Output error message as html.
     *
     * Avoid relying on MW stuff, as it might not be setup yet.
     * We don't bother translating, as the user may not have even set lang yet.
     *
     */
    private function renderHtml() {
        if ( !headers_sent() ) {
            HttpStatus::header( 500 );
            header( 'Content-Type: text/html; charset=UTF-8' );
        }

        $templateParser = new TemplateParser( null, new EmptyBagOStuff() );

        try {
            echo $templateParser->processTemplate(
                'ExtensionConfigError',
                [
                    'version' => MW_VERSION,
                    'path' => $this->path,
                    'type' => $this->isSkin ? 'skin' : 'extension',
                    'error' => $this->error,
                    'extName' => $this->extName,
                    'trace' => $this->getTraceAsString(),
                    'mwLogo' => $this->getMWLogo(),
                ]
            );
        } catch ( Exception $e ) {
            echo 'Error: ' . htmlspecialchars( $e->getMessage() );
        }
    }

    /**
     * Render the error for CLI
     */
    private function renderText() {
        $type = $this->isSkin ? 'skin' : 'extension';
        echo "Error: The $this->extName $type cannot be loaded. "
            . "Check that all of its files are installed properly.\n\n";
        echo $this->getTraceAsString();
        echo "\n";
    }

    /**
     * Output an error response and exit.
     *
     * @return never
     */
    public function render() {
        if ( wfIsCli() ) {
            $this->renderText();
        } else {
            $this->renderHtml();
        }
        // Make sure that the error gets into logs.
        // This will also stop execution.
        trigger_error( $this->getMessage(), E_USER_ERROR );
    }

    /**
     * Get the url for the MW logo
     *
     * @return string
     */
    private function getMWLogo() {
        global $wgResourceBasePath;
        $suffix = "/resources/assets/mediawiki.png";
        if ( $wgResourceBasePath !== null ) {
            // We are early in setup, so we can't rely on this.
            return $wgResourceBasePath . $suffix;
        }
        $path = '/';
        foreach ( array_filter( explode( '/', $_SERVER['PHP_SELF'] ) ) as $part ) {
            if ( !preg_match( '/\.php$/', $part ) ) {
                $path .= "$part/";
            } else {
                break;
            }
        }

        return $path . $suffix;
    }
}

/** @deprecated class alias since 1.43 */
class_alias( MissingExtensionException::class, 'MissingExtensionException' );