Question

class PositionModel(models.Model):
    xpos = models.IntegerField()
    ypos = models.IntegerField()
    def relative(self, x, y):
        self.__class__.objects.filter(xpos = self.xpos + x,
                                      ypos = self.ypos + y)
    class Meta:
        abstract = True

This example allows you to inherit PositionModel in several different models, then use the relative(x,y) function to perform a query based on the model of the child.

Does Django have some other, preferred way to write functions in abstract models that use the child’s manager?

Answer 1

Proxy Models are meant to add extra methods or funcionality to the models, without messing with the fields/db… but as you want to inherit this method on more than one model, and Proxy-models are connected to one non-abstract class only, and xpos + ypos are being inherited too, I guess an abstract class could be the best choice to do the job.