<div class="block">
    <ul class="nav nav-tabs nav-tabs-alt" data-toggle="tabs" role="tablist">
        <?php $tidx = 0;
        foreach ($this->extends as $tkey => $tab) { ?>
            <li class="nav-item"><a class="nav-link <?php echo $tidx ?: 'active'; ?>" href="#ext-<?php echo $key; ?>-<?php echo $tkey; ?>"><?php echo $tab['title']; ?></a></li>
        <?php $tidx++;
        } ?>
    </ul>
    <div class="block-content">
        <div class="tab-content">
            <?php $tidx = 0;
            foreach ($this->extends as $tkey => $tab) { ?>
                <div id="ext-<?php echo $key; ?>-<?php echo $tkey; ?>" class="tab-pane <?php echo $tidx ?: 'active'; ?>" role="tabpanel">
                    <?php include $tab['path']; ?>
                </div>
            <?php $tidx++;
            } ?>
        </div>
    </div>
</div>