How do I update a variable set by 'with' in Django Template

Question

Following is the code where I need to update a variable.

{% with a=1 %}
{% for x in object_list %}
    {% if 'clone' in x.game and a is 1 %}
        <div class="alert alert-primary">
            <h2 class="p-3">{{ x.title }}</h2>
        </div>
        {{ a=2 }} # here is where I update it
    {% endif %}
{% endfor %}
{% endwith %}

but instead of {{ a=2 }} setting a to 2, it throws the following error:

TemplateSyntaxError at /
Could not parse the remainder: '=2' from 'a=2'

The idea is *not* to *update* variables. The `{% with a=1 %}` will assign a value to `a`, Django templates do *not* redefine the `a` variable. Such logic does *not* belong in the template, but in the view. — Willem Van Onsem, Jun 30 '21 at 18:53
@WillemVanOnsem But how to do that in the view? Thanks in advance! — union77, Dec 10 '22 at 10:52

score 1 · Accepted Answer · answered Jun 30 '21 at 18:56

1

There is no way to reassign a variable in a with template tag.

You should do that in the backend (view) or by loading the variable into JavaScript and perform what you want to do it it can be client-side.

answered Jun 30 '21 at 18:56

Frederic Perron

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4
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Can you give some hints on how to do that in the backend? Many thanks! – union77 Dec 10 '22 at 10:51
You could take a look at this this thread: https://stackoverflow.com/questions/1070398/how-to-set-a-value-of-a-variable-inside-a-template-code – Frederic Perron Dec 10 '22 at 23:51

score 0 · Answer 2 · edited Jul 01 '21 at 01:33

0

Like everyone is saying, you can do this logic in the view. But, instead of reassigning a to 2, you can just add 1:

{% with a=1 %}
{% for x in object_list %}
    {% if 'clone' in x.game and a is 1 %}
        <div class="alert alert-primary">
            <h2 class="p-3">{{ x.title }}</h2>
        </div>
        {{ a|add:"1" }} # this is the changed code
    {% endif %}
{% endfor %}
{% endwith %}

edited Jul 01 '21 at 01:33

Dharman

30,962
25
85
135

answered Jul 01 '21 at 01:27

theProCoder

390
6
21

1

oh, sorry, I guess I was writing for Django 3.2 (the latest version at the time of writing). Sorry about that, but I do recommend to start using Django 3 as it has lot's of new features. :) – theProCoder Sep 12 '21 at 01:15

How do I update a variable set by 'with' in Django Template

2 Answers2