Suppose I have a django template with the following context:
data1 = "this is data1"
data2 = "this is data2"
data_name = "data2"
Now I know the value of data_name(assume it's "data2"), is it possible to use it to access the variable data2?
To make my intention clearer, this is how you might do it with Python
>>> a = 1
>>> b = 2
>>> name = 'a'
>>> locals()[name]
1
>>> name = 'b'
>>> locals()[name]
2
With builtin template filters, tags, it's impossible. You should define custom tags to do it.
Example:
from django import template
register = template.Library()
@register.simple_tag(takes_context=True)
def get_by_name(context, name):
return context[name]
Example usage (assume tag is defined in APP_DIR/templatetags/name.py):
>>> from django.template import Template, Context
>>> t = Template('''
... {% load name %} {# Don't forget to load #}
... {% get_by_name data_name %}
... ''')
>>> output = t.render(Context({
... 'data1': 'this is data1',
... 'data2': 'this is data2',
... 'data_name': 'data2',
... }))
>>> print(output)
this is data2
This custom filter will allow you to get a given property of a given context variable. In your app folder, create a folder called templatetags and insert this content into templatetags/custom_tags.py:
from django import template
register = template.Library()
@register.filter()
def get_key(value, arg):
if arg in value:
return value[arg]
else:
return ''
Here is an example using this in a template that handles a a form (there is a variable called "form" in the context). This gets the property "username" of the context variable "form.errors".
{% load custom_tags %}
{{ form.errors | get_key:"username" }}
