CODEWITHSUNDEEP
pythondjangodjango-models
Hellnar
Hellnar

Reputation: 64883

Django: Call self function inside a Django model

I want to call for a self function of a model class as such in upload_to:

class Foo(models.Model):
    filestack = models.FileField(upload_to=self. gen_save_path)

    def gen_save_path(self):
        """
        gen_save_path: void -> String
        Generates the path as a string for fileStack field.
        """
        return "some generated string"

However I am getting NameError: name 'self' is not defined error

Upvotes: 3

Views: 5504

Answers (3)

Anurag Uniyal
Anurag Uniyal

Reputation: 88845

filestack is a class attribute and while declaring it you can not use self as there is no object of class (self) yet created, anyway according to django docs upload_to takes two arguments, instance (An instance of the model where the FileField is defined) and filename (The filename that was originally given to the file), so you can set upload_to to such function

def gen_save_path(instance, filename):
    """
    gen_save_path: void -> String
    Generates the path as a string for fileStack field.
    """
    return "some generated string"

class Foo(models.Model):

    filestack = models.FileField(upload_to=gen_save_path)

If you wish to include gen_save_path inside the class, you can use a lambda to call self.gen_save_path e.g.

class Foo(models.Model):

    filestack = models.FileField(upload_to=lambda self, fname:self.gen_save_path(fname))

    def gen_save_path(self, filename):
        return "some generated string"

Upvotes: 5

dweeves
dweeves

Reputation: 5615

in your code, the filestack is a class wide scope variable since not defined in a method. so there is no available self in this scope.

i think you can use :

filestack =models.FileField(upload_to=Foo.gen_save_path)

or

define filestack value within a __init__ constructor, where you can use self !!

Upvotes: -2

muksie
muksie

Reputation: 13063

I think this will work if you use a lambda function:

class Foo(models.Model):
    filestack = models.FileField(upload_to=lambda: self.gen_save_path())

    def gen_save_path(self):
        """
        gen_save_path: void -> String
        Generates the path as a string for fileStack field.
        """
        return "some generated string"

Upvotes: -2

Related Questions