Determine variable type within django template

Question

I have a variable that I'm pulling into a table that sometimes is a date and sometimes is a string. If the variable is a date, I want to change the formatting:

<td>{{ action.extra_column|date:"M d" }}</td>

But if it is a string, I just want to display it as is:

<td>{{ action.extra_column }}</td>

If I try to format it and it is a string, I get no output for the variable.

How can I determine the type so that I can adjust my rendering based on type.

Answer 1

You could also implement a general template filter as an equivalent to the type() builtin:

# app/templatetags/util.py
from django import template

register = template.Library()

@register.filter
def get_type(value):
    return type(value)

# template.html
{% load util %}
{% if extra_column|get_type == 'str' %}
    String
{% elif extra_column|get_type == 'datetime.date' %}
    Date
{% else %}
    Oh no!
{% endif %}

I think Ignacio and Dirk are right, however. Can't you just have two keys (you say "array", but I assume you mean "dictionary" from the fact that the items have names) called date and detail?

# views.py
...
actions = [{
    'some_property': 'some_value'
    'date': None,
    'detail': 'details'
},
{
    'some_property': 'some_value'
    'date': datetime.date.today(),
    'detail': None
}]
...

# template.html
{% for action in actions %}
<td>{% if action.date %}{{ action.date|date:"M d" }}{% endif %}{{ action.detail }}</td>
{% endfor %}

# output
<td>details</td>
<td>Aug 19</td>