Django template using variable in two blocks - django

Question

This is my template code:
{% block content %}
{% get_latest as latest_posts %}
<ul>
{% for post in latest_posts %}
<li>
<p>{{ post.title|safe }}</p>
</li>
{% endfor %}
</ul>
{% endblock %}
{% block sidebar %}
<ul>
{% for post in latest_posts %}
<li>
<p>{{ post.title|safe }}</p>
</li>
{% endfor %}
</ul>
{% endblock %}
In the content block the for loop does works, but in the sidebar block I can't use the variable latest_posts. Can anyone help me with this?

Answer 1

The variable's scope is limited to the containing {% block content %}. You can either repeat the declaration inside {% block sidebar %}, or move it up a level so it's outside of {% block content %}.
example
{% get_latest as latest_posts %}
{% block content %}
<ul>
{% for post in latest_posts %}
<li>
<p>{{ post.title|safe }}</p>
</li>
{% endfor %}
</ul>
{% endblock %}
{% block sidebar %}
<ul>
{% for post in latest_posts %}
<li>
<p>{{ post.title|safe }}</p>
</li>
{% endfor %}
</ul>
{% endblock %}
or
{% block content %}
{% get_latest as latest_posts %}
<ul>
{% for post in latest_posts %}
<li>
<p>{{ post.title|safe }}</p>
</li>
{% endfor %}
</ul>
{% endblock %}
{% block sidebar %}
{% get_latest as latest_posts %}
<ul>
{% for post in latest_posts %}
<li>
<p>{{ post.title|safe }}</p>
</li>
{% endfor %}
</ul>
{% endblock %}

Answer 2

You can use the with statement:
Definition:
with Caches a complex variable under a simpler name. This is useful
when accessing an “expensive” method (e.g., one that hits the
database) multiple times.
Wrap your existing block into this with clause and you can safe yourself some queries. also it should solve your problem :-) Just remove the {% get_latest as latest_posts %} line
{% with latest_posts=get_latest %}
{% block content %}
<ul>
{% for post in latest_posts %}
<li>
<p>{{ post.title|safe }}</p>
</li>
{% endfor %}
</ul>
{% endblock %}
{% block sidebar %}
<ul>
{% for post in latest_posts %}
<li>
<p>{{ post.title|safe }}</p>
</li>
{% endfor %}
</ul>
{% endblock %}
{% endwith %}