Django forms with clean_field(self) return empty element on raise

Question

I created a ModelForm in this way.

class Mant(forms.Modelform):
    start_date=forms.CharField()
    stop_date=forms.CharField()

    def clean_start_date(self):
        tz=self.request.session.get('timezone','UTC')
        data=self.cleaned_data['start_date']
        try:        
            date_parsed=arrow.get(data,'YYYY-MM-DD HH:mm').replace(tzinfo=tz)

        except ParserError as e:
            raise forms.ValidationError("invalid format")


        return date_parsed.format('YYYY-MM-DD HH:mm:ssZZ')

    def clean_stop_date(self):
        tz=self.request.session.get('timezone','UTC')
        data=self.cleaned_data['stop_date']
        try:        
            date_parsed=arrow.get(data,'YYYY-MM-DD HH:mm').replace(tzinfo=tz)

        except ParserError as e:
            raise forms.ValidationError("invalid format")


        return date_parsed.format('YYYY-MM-DD HH:mm:ssZZ')

The form works nice. validate current dates and all. but my problem is that when there is some problems parsing the date (or any other thing that i add that raise an error) the field comes empty and the user need to select the date all over again.

Every time I see a validation error normal in django the field filled by the user comes back so the user can correct it. but in my case when clean_field is replaced the value filled by the user disappears. there is a way to Fix this?.

Also looks like if the firs element Raise an exception the validation is stopped altogether and all the others errors aren't returned and theirs fields emptied :(

Answer 1

Sorry for answering my own question.

My problem was at template level.

my template was waging for a diatomite object because need to localize the date in the timezone of the user. but when there was an error in the form. the value did not contain a datetime object. just a buffer with the previous input. so the timezone date tags failed to parse the data. printing an empty value.

now the part in the form looks like this.

<input class="form-control datetimepicker" data-date-format="YYYY-MM-DD HH:mm" id="id_start_date" name="start_date" type="text" 
                {%if form.errors %}
                value="{{field.value}}"
                {%else%}
                value="{{field.value|timezone:user_timezone|date:"Y-m-d H:i"}}" 

                {% endif %}

when the form came with a errors array Im aware of this and just print the value