Rendering template object in an if comparison string

Question

I've been trying to do this and getting no results

<ul>
    {% for topic in topics %}
        <li {% if request.get_full_path == "/topic/{{ topic.topic_slug }}/" %}class="is-active"{% endif %}>
            <a href="{% url "TopicView" topic.topic_slug %}">{{ topic.topic_name }}</a>
        </li>
    {% endfor %}
</ul>

The error, I'm guessing is from the {{ topic.topic_slug }} being rendered in the string. I'd like it to be "/topic/tech/" during rendering but that seems not to be working.

Answer 1

I don't believe you can use {{ }} inside a {% %} so you need to do this in a different way. There are many possibilities.

Try using

 {% if request.get_full_path == "/topic/"+topic.topic_slug+"/" %}

but the way I would do it is to simply use your class to do the work of returning the path. /topic/tech/ looks like what people usually return from a get_absolute_url class function:

 class Topic:

     ...

     def get_absolute_url(self):
         return '/topic/{}/'.format(self.topic_slug)

and then in your template, simply use:

 {% if request.get_full_path == topic.get_absolute_url %}

(Note that if you already have an absolute_url, simply use another function name. e.g. get_my_topic_slug_url()).