src/Silex/Composer/ScriptHandler.php
public static function assetsInstall(Event $event)
    {
        $options = self::getOptions($event);
        $consoleDir = self::getConsoleDir($event, 'install assets');

        if (null === $consoleDir) {
            return;
        }

        $webDir = $options['web-dir'];

        $symlink = '';
        if ($options['assets-install'] == 'symlink') {
            $symlink = '--symlink ';
        } elseif ($options['assets-install'] == 'relative') {
            $symlink = '--symlink --relative ';
        }

        if (!self::hasDirectory(
            $event, 'web-dir', $webDir, 'install assets'
        )) {
            return;
        }

        static::executeCommand(
            $event, $consoleDir, 'assets:install '.
            $symlink.escapeshellarg($webDir)
        );
    }
public static function assetsInstall(Event $event)
    {
        $options = self::getOptions($event);
        $consoleDir = self::getConsoleDir($event, 'install assets');

        if (null === $consoleDir) {
            return;
        }

        $webDir = $options['web-dir'];

        $symlink = '';
        if ($options['assets-install'] == 'symlink') {
            $symlink = '--symlink ';
        } elseif ($options['assets-install'] == 'relative') {
            $symlink = '--symlink --relative ';
        }

        if (!self::hasDirectory(
            $event, 'web-dir', $webDir, 'install assets'
        )) {
            return;
        }

        static::executeCommand(
            $event, $consoleDir, 'assets:install '.
            $symlink.escapeshellarg($webDir)
        );
    }
Installs the assets under the web root directory.

For better interoperability, assets are copied
instead of symlinked by default.

Even if symlinks work on Windows, this is only true on Windows
Vista and later, but then, only when running the console with admin
rights or when disabling the strict user permission checks
(which can be done on Windows 7 but not on Windows Vista).

@param Event $event Composer event instance

@return void