Django template IF condition with logical breckets and precedence order

user_3578861 0
Viewed 4056

In my django template I have

{% if object_not_readonly and user_is_worker or user_is_admin %}

Django doc tell me

Use of both and and or clauses within the same tag is allowed, with and having higher precedence than or

I think this is not obvious way to declare logical precedence in IF clause.

Question is:

Is it something like {% if object_not_readonly and ( user_is_worker or user_is_admin ) %} condition in django template language, with obvious clause like if A and (C or B) and (not Z)?

django-templates django
3 Answers

It's not clear what you're asking here, or what result you are trying to achieve with your example statement:

{% if object_not_readonly and user_is_worker or user_is_admin %}

To clarify what they mean in the reference docs by "Use of both and and or clauses within the same tag is allowed, with and having higher precedence than or", the above statement would be evaluated as:

{% if (object_not_readonly and user_is_worker) or user_is_admin %}

which is not the same as {% if object_not_readonly and ( user_is_worker or user_is_admin ) %}

user_35873390

In order to be perfectly safe, I would split it up like this:

{% if object_not_readonly %} 
    {% if user_is_worker or user_is_admin %}

        ...

    {% endif %}
{% endif %}
user_14433750

According the documentation, if you can't solve your problem with the default precedence then you must use nested if. As Adam mentioned already:

{% if object_not_readonly %} 
   {% if user_is_worker or user_is_admin %}

    ...

   {% endif %}
{% endif %}

https://docs.djangoproject.com/en/4.0/ref/templates/builtins/#std-templatetag-if

Use of actual parentheses in the if tag is invalid syntax. If you need them to indicate precedence, you should use nested if tags. I hope it helps.

user_46417050
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