CODEWITHSUNDEEP
pythondjango
user10332687
user10332687

Reputation:

How to update from within a model method

I have the following method I am trying to write:

class MTurk(models.Model):
    ...

    def parse(self, url):

        res = requests.get(url)
        node = html.fromstring(res.content)
        data = MTurk()._parse_page(node)

        self.update(**data)

However, when I try and do self.update(**data) it tells me:

AttributeError: 'MTurk' object has no attribute 'update'

Normally I would do MTurk.objects.filter(pk=self.pk).update(**data), but is there a way to do this from within the model method itself without having to re-call everything?

Upvotes: 0

Views: 545

Answers (1)

Johan
Johan

Reputation: 3611

The update function doesn't seem to be accessible from an individual object, but is rather used on a QuerySet.

It's however not a very Djangonic way of handling that kind of functionality, but you'd rather want to save the model outside the model, basically from the function/place that called parse in the first place, basically like this:

# Fetch an object
mturk = MTurk.objects.get(id=1)
# Call the parse method
mturk.parse(my_url)
# Save the object
mturk.save()

You could however still call the save function from within the model of course, in that case you'd just replace the update function with a save function, and you'd need to store the values to the model with self.

The save function also takes an argument update_fields=[] in which you can specify which fields you want to save (and ignore the rest). This might be what you're looking for.

class MTurk(models.Model):
    ...

    def parse(self, url):

        res = requests.get(url)
        node = html.fromstring(res.content)
        data = MTurk()._parse_page(node)

        self.data_1 = node # Store some data
        self.data_2 = data # Store some more data
        # Only save the given fields
        self.save(update_fields=["data_1", "data_2])

Upvotes: 1

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