Tukukkk

I am trying to access the values_list of a query_set in a template.

In a view I have used the following if statement to determine whether an Outcome (model) exists for a given Participant (model):

if not form.cleaned_data['timepoint'] in patient.outcome_set.values_list('timepoint', flat=True):

This worked perfectly - now I want to be able to do something similar with the values_list in a template. However, when I try to limit the values_list to just the timepoint variable on the model, it throws a TemplateSyntaxError Could not parse the remainder: '('template')' from 'patient.outcome_set.values_list('template')'

If I print the values_list to the screen using {{ patient.outcome_set.values_list }} it prints all the values of each outcome fine, but I can't work out how to limit the values_list to just the timepoint variable.

Current template:

<table>

  <thead>

    <tr>

      <th>Patient</th>

      <th>Baseline</th>

      <th>Follow-up</th>

    </tr>

  </thead>

  <tbody>

    {% for patient in patients %}

      <tr>

        <td>{{ patient.name }}</td>



        {% if 'baseline' in patient.outcome_set.values_list('timepoint') %}

          <td>INSERT TICK</td>

        {% else %}

          <td>INSERT CROSS</td>

        {% endif %}



        {% if 'followup' in patient.outcome_set.values_list('timepoint') %}

          <td>INSERT TICK</td>

        {% else %}

          <td>INSERT CROSS</td>

        {% endif %}



      </tr>

    {% endfor %}

  </tbody>

</table>

Though this kind of logic is more suited in views, you can use a custom template tag for this. Something like below.

# extra_tags.py



@register.filter

def get_value_in_qs(queryset, key):

    return queryset.values(key, flat=True)

Then you can use it in your template in this way:

{% load extra_tags %}

...

    {% for patient in patients %}

      <tr>

        <td>{{ patient.name }}</td>



        {% if 'baseline' in patient.outcome_set|get_value_in_qs:'timepoint' %}

# or for better readability use a with tag

{% with patient_timepoint=patient.outcome_set|get_value_in_qs:'timepoint' %}

{% if 'baseline' in patient_timepoint %} ...







....