如何在 Django 模板中使用 break 和 continue？

Question

I want to put break and continue in my code, but it doesn't work in Django template. How can I use continue and break using Django template for loop. Here is an example:

{% for i in i_range %}
{% for frequency in patient_meds.frequency %}
{% ifequal frequency i %}
<td class="nopad"><input type="checkbox" name="frequency-1" value="{{ i }}" checked/> {{ i }} AM</td>
{{ forloop.parentloop|continue }} ////// It doesn't work
{ continue }                      ////// It also doesn't work
{% endifequal %}
{% endfor%}
<td class="nopad"><input type="checkbox" name="frequency-1" value="{{ i }}"/> {{ i }} AM</td>
{% endfor %}

Answer 1

Django doesn't support it naturally.

You can implement forloop|continue and forloop|break with custom filters.

http://djangosnippets.org/snippets/2093/

Answer 2

For-loops in Django templates are different from plain Python for-loops, so continue and break will not work in them. See for yourself in the Django docs , there are no break or continue template tags. Given the overall position of Keep-It-Simple-Stupid in Django template syntax, you will probably have to find another way to accomplish what you need.

Answer 3

For most of cases there is no need for custom templatetags, it's easy:

continue :

{% for each in iterable %}
  {% if conditions_for_continue %}
       <!-- continue -->
  {% else %}
       ... code ..
  {% endif %}
{% endfor %}

break use the same idea, but with the wider scope:

{% set stop_loop="" %}
{% for each in iterable %}
  {% if stop_loop %}{% else %}
       ... code ..
       under some condition {% set stop_loop="true" %}
       ... code ..
  {% endif %}
{% endfor %}

if you accept iterating more than needed.

Answer 4

If you want a continue/break after certain conditions, I use the following Simple Tag as follows with "Vanilla" Django 3.2.5:

@register.simple_tag def define(val=None): return val

Then you can use it as any variable in the template

{% define True as continue %}

{% for u in queryset %}

{% if continue %}

{% if u.status.description == 'Passed' %}
  <td>Passed</td>
  
  {% define False as continue %}

{% endif %}

{% endif %}

{% endfor %}

Extremely useful for any type of variable you want to re-use on template without using "with" statements.