Django template - dynamic variable name

Question

Good Afternoon,

How can I use a variable variable name in Django templates?

I have a custom auth system using context, has_perm checks to see if the user has access to the specified section.

deptauth is a variable with a restriction group name i.e SectionAdmin. I think has.perm is actually checking for 'deptauth' instead of the variable value SectionAdmin as I would like.

{%if has_perm.deptauth %}

How can I do that? has_perm.{{depauth}} or something along those lines?

EDIT - Updated code

{% with arg_value="authval" %}
{% lookup has_perm "admintest" %}
{% endwith %}
{%if has_perm.authval %}
window.location = './portal/tickets/admin/add/{{dept}}/'+val; 
{% else %}
window.location = './portal/tickets/add/{{dept}}/'+val; 
{%endif%} 

has_perm isn't an object.. it's in my context processor (permchecker):

class permchecker(object):
def __init__(self, request):
 self.request = request
 pass
def __getitem__(self, perm_name):
 return check_perm(self.request, perm_name) 

• Aamir Rind: has_perm is this your custom template tag?
• Joe: has_perm cannot be a custom template tag. The template tag is if.

Answer 1

You're best off writing your own custom template tag for that. It's not difficult to do, and normal for this kind of situation.

I have not tested this, but something along these lines should work. Remember to handle errors properly!

def lookup(object, property):
 return getattr(object, property)()
register.simple_tag(lookup)

If you're trying to get a property rather than execute a method, remove those ().

and use it:

{% lookup has_perm "depauth" %}

Note that has_perm is a variable, and "depauth" is a string value. this will pass the string for lookup, i.e. get has_perm.depauth.

You can call it with a variable:

{% with arg_value="depauth_other_value" %}
 {% lookup has_perm arg_value %}
{% endwith %}

which means that the value of the variable will be used to look it up, i.e. has_perm.depauth_other_value'.

• jdotjdot: Agreed. Unfortunately, Django templates are not great for the kind of finer distinction that you're trying to make here.
• user2355278: Hi, I'm getting this error: 'proxy' object has no attribute 'admintest'. Looks like it's treating admintest as a property instead of a lookup string
• Joe: What exactly is admintest? Is it a dictionary? Show the code you are using to call the template tag.
• user2355278: Hi, admintest is just a string. has_perm takes this string and checks the DB to see if the user has access to the group this string represents
• user2355278: {% with arg_value="authval" %} {% lookup has_perm "admintest" %} {% endwith %} {%if has_perm.authval %} window.location = './portal/tickets/admin/add/{{dept}}/'+val; {% else %} window.location = './portal/tickets/add/{{dept}}/'+val; {%endif%}

Answer 2

You can try like this,

{{ dict|key:key_name }}

Filter:

def key(d, key_name):
 return d[key_name]
key = register.filter('key', key)

More information, django ticket

• Joe: This only works for a dictionary, not attributes of an object.