jekyll page.url不能正常工作

Question

让我们说这是代码片段：

<ul>
{% assign navigation = site.data.nav %}
{% for link in navigation %}
    {% assign active = nil %}
    {% for sublink in link.submenu %}
        {% if page.url contains sublink.url %}
            {% assign active = 'active' %}
        {% endif %}
    {% endfor %}
    {% if page.url contains link.url %}
        {% assign active = 'active' %}
    {% endif %}
    <li class="{{ active }}>
        <a href="{{ site.baseurl }}{{ link.url }}">{{ link.text }}</a>
        {% if link.submenu %}
        <ul>
            {% for sublink in link.submenu %}
            <li {% if page.url contains sublink.url %}class="active"{% endif %}>
                <a href="{{ site.baseurl }}{{ sublink.url }}">{{ sublink.text }}</a>
            </li>
            {% endfor %}
        </ul>
        {% endif %}
    </li>
{% endfor %}
</ul>

nav.yml文件如下所示：

- text: First Menu
  url: /modules/some text/introduction/

- text: Second Menu
  url: /modules/some more text/intro-text/
  submenu:
  - text: Level Two First
    url: /modules/level two first/intro-text/
  - text: Level Two Second
    url: /modules/level two second/intro-text/

因此，每个菜单项都会渲染，并且工作正常。但我在这里遇到的唯一问题是变量active是不会根据那些而不是保持零更新。即使page.url包含sublink.url或link.url，以下行也没有获得活动类的呈现

<li {% if page.url contains sublink.url %}class="active"{% endif %}>

可能是什么问题？