Auto populate a date field when a certain choice is made in choices

Using Django Forms & APIs
1

I’m trying to auto populate (update) a datefield, when a certain choice is chosen by the user:
following is my code

class Tasks(models.Model):
    name = models.CharField(max_length=255)
    boat = models.ForeignKey(Boat, on_delete=models.CASCADE, null=True, blank=True)
    assigned_to = models.ForeignKey(Technician, on_delete=models.SET_NULL, null=True, blank=True)
    created_by = models.ForeignKey(Person, on_delete=models.SET_NULL, null=True, blank=True)
    created_date = models.DateTimeField(default=datetime.now, blank=True)
    completed_date = models.DateField(null=True, blank=True)

    CONDITION_STATUS = (
        ('c', 'Completed'),
        ('p', 'Pending'),
        ('i', 'Incomplete'),
    )


    status = models.CharField(
        max_length=1,
        choices=CONDITION_STATUS,
        blank=True,
        default='i',
    )

as you can see, I want, when a technicain choses completed choice, it to automatically trigger an insert on datetime to the completed_date field.

I’m trying this with a clean method in my forms.modelForm class:

class TaskForm(forms.ModelForm):

    class Meta:
        model = Task

        fields = ( 
            'created_by',
            'created_date',
            'completed_date',
	**....
            )

        def clean(self):
            cleaned_data = super().clean()
            if self.errors:
                return cleaned_data
            choice = cleaned_data.get('status')
            if choice == 'c':
                cleaned_data['completed_date'] = datetime.date.today()
            return cleaned_data
	
	**....

however it seems it is not working, and what is the best approach to it, or can point me to the right direction

thanks.

2

You’re not showing a status field in your form. There doesn’t appear to be anything to check.

3

I have managed to solve this issue by overriding the save method in my model:

  def save(self, *args, **kwargs):
        if self.status == 'c':
            self.completed_date = timezone.now()
        super().save(*args, **kwargs)

is this django’s best practiced way to accomplish my desired results, or should I introduce the status field in to my Form, and use a clean_data() method to get my desired result.

thanks

4

I’m not sure this is what you want either. In this case, every time this model is saved after having the status == ‘c’, the date’s going to be updated. (Whether you want this to happen is only something you can decide.)

5

yes, it will get updated. I think i can bypass it through the templates, for now. Thanks.

6

Actually, no. Your templates aren’t going to have any effect on that at all. With that setting in your model, any time a model instance is saved for any reason, when the status is ‘c’, the completed_date will be updated.

I’m suspecting that what you really want to do is only update the completed_date the first time the status becomes ‘c’.

7

I’ve update the logic to :

    def save(self, *args, **kwargs):
        if self.status == 'c' and self.completed_date is None:
            self.completed_date = timezone.now()
        super().save(*args, **kwargs)

so in the first time it will be saved, but if an value exists in the completed_date its value won’t be updated, can share feedback to improve

thanks

1 Like