In a Django model passing a param to a method and using it in the code is easy.
Class Foo(models.Model):
number = IntegerField()
...
def bar(self, percent):
return self.number * percent
f = Foo(number=250)
f.bar(10)
The question is how can this be done in the template layer? Somthing like :
{{ foo.bar(10) }}
The simple answer is that you can't do this, which is by design; Django templates are designed to be keep you from writing real code in them. Instead, you'd have to write a custom filter, e.g.
@register.filter
def bar(foo, percent):
return foo.bar( float(percent) )
This would let you make a call like {{ foo|bar:"250" }} which would be functionally identical to your (non-working example) of {{ foo.bar(250) }}.
By design, Django templates don't allow you to invoke methods directly so you'd have to create a custom template tag to do what you want.
Jinja2 templates do allow you to invoke methods, so you could look into integrating Jinja2 with Django as another option.
Just do this calculation in the view, and not the template.
This is often the solution to many "template language can't do X" problems.
foo = Foo(number=250)
foo.bar = foo.bar(10)
return direct_to_template(request, "foo.html", {'foo': foo})
{{ foo.bar }}
