Django ImageField passing a callable to upload_to

Question

I'm trying to pass a custom upload_to function to my models imageField but I'd like to define the function as a model function....is that possible?

class MyModel(models.Model):
    ...
    image = models.ImageField(upload_to=self.get_image_path)
    ...

    def get_image_path(self, filename):
        ...
        return image_path

Now i know i can't reference it by 'self' since self doesn't exist at that point...is there a way to do this? If not - where is the best place to define that function?

possible duplicate of [Django FileField with upload_to determined at runtime](http://stackoverflow.com/questions/1190697/django-filefield-with-upload-to-determined-at-runtime) — Paulo Scardine, Feb 01 '12 at 08:10
Yeah, look at the link that Paulo mentions - it shows it clearly there (no `self.`, define the callable as a function in the models.py) — Steve Jalim, Feb 01 '12 at 11:49
Looks like my answer is here after all: http://stackoverflow.com/questions/1190697/django-filefield-with-upload-to-determined-at-runtime — jduncan, May 30 '12 at 03:29

score 9 · Answer 1 · answered Feb 14 '13 at 23:43

So Just remove "@classmethod" and Secator's code will work.

class MyModel(models.Model):

    # Need to be defined before the field    
    def get_image_path(self, filename): 
        # 'self' will work, because Django is explicitly passing it.
        return filename

    image = models.ImageField(upload_to=get_image_path)

Mariusz Jamro · Answer 2 · 2019-02-26T07:24:28.550

2

You can use staticmethod decorator to define the upload_to inside of a class (as a static method). Hovever it has no real benefit over typical solution, which is defining the get_image_path before class definition like here).

class MyModel(models.Model):

    # Need to be defined before the field
    @classmethod       
    def get_image_path(cls, filename): 
        # 'self' will work, because Django is explicitly passing it.
        return filename

    image = models.ImageField(upload_to=get_image_path)

edited Feb 26 '19 at 07:24

answered Feb 13 '12 at 16:30

Mariusz Jamro

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@Secator: I tried this in my own code but it's not actually calling the method-- for the file location, I'm getting "Currently: /o7pDX.jpg" – Colleen Apr 26 '12 at 16:40
@Colleen, it's converting my staticmethod to a string too. Looks like the method has to be a direct attribute of the module (or of some module). – mjumbewu Jan 04 '13 at 23:09
it works find if you just define `get_image_path` as a normal method without `@classmethod` – laike9m Jan 10 '14 at 11:05
in a `@classmethod`, the first param should be the class not the object. To make it less confused, I think you should use `cls` instead of `self` – Nathan Do Feb 25 '19 at 04:47

Django ImageField passing a callable to upload_to

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