Django choice field default value and readonly - django

Question

I try to set my field in form readonly and put any default value.
This is a part of my form:
category = forms.CharField(widget=forms.TextInput(attrs={'readonly':
'readonly'}),
initial=Category.objects.get(name='Zdrowie i uroda'))
class Meta:
model = Site
fields = ('url', 'name', 'description', 'keywords', 'group', 'category',
'subcategory', 'category1', 'subcategory1')
I get an error: Cannot assign "'Zdrowie i uroda'": "Site.category" must be a "Category" instance.
This is my site model:
class Site(models.Model):
category = models.ForeignKey('Category')
subcategory = ChainedForeignKey(
'SubCategory',
chained_field='category',
chained_model_field='category',
show_all=False,
auto_choose=True)
name = models.CharField(max_length=70)
description = models.TextField()
# importuje zmienione TextFields widgets.py
keywords = MyTextField()
date = models.DateTimeField(default=datetime.now, editable=False)
url = models.URLField()
is_active = models.BooleanField(default=False)
category1 = models.ForeignKey('Category', related_name='category', blank=True, null=True, default=None)
subcategory1 = ChainedForeignKey(
'SubCategory',
chained_field='category1',
chained_model_field='category',
related_name='subcategory',
show_all=False,
auto_choose=True, blank=True, null=True, default=None)
group = models.CharField(max_length=10, choices=(('podstawowy', 'podstawowy'),
('premium', 'premium')), default='podstawowy')
def get_absolute_url(self):
return reverse('site', args=[str(self.category.slug),
str(self.subcategory.slug), str(self.id)])
def get_thumb(self):
host = urlparse(self.url).hostname
if host.startswith('www.'):
host = host[4:]
thumb = 'http://free4.pagepeeker.com/v2/thumbs.php?size=s&url=' + host
return thumb
class Meta:
verbose_name_plural = "Strony"
def __str__(self):
return self.name
I can't deal with it. Any clues?
Finally I excluded category, subcategory fields from my model.form and added it to html source manually:
{{ form_extended|bootstrap }}
<label for="example-text-input" class="col-2 col-form-label">Category</label>
<input class="form-control form-control-lg" type="text" name="category" disabled required value="{{ form_extended.initial.category.name }} " />
<label for="example-text-input" class="col-2 col-form-label">Subcategory</label>
<input class="form-control form-control-lg" type="text" name="subcategory" disabled required value="{{ form_extended.initial.subcategory.name }} " />
I don't think it is a right way but I can't put some data to form initial values. Should I create my form manually from scratch? My way isn't good because I use jQuery to extend form. Now category, subcategory fields are las but they shouldn't (when user choose "premium" group from choice fields, after subcategory field there should appear "category1", "subcategory1" fields...
As always - I am sorry for my terrible English. Every post is like exam to me.

Answer 1

Options without further delving into Django forms:
Change Model Field
This might not be an option, but you could try setting:
class Site(models.Model):
category = models.ForeignKey('Category', editable=False)
Remove the explicit declaration of the category form field from your form and simply set the initial category when initializing the form or override __init__ to set it.
Change Form Field
Django would normally render a ForeignKeyField as drop down. Do you explicitly want a text input instead? In that case you have to handle data validation and the data mapping yourself.
A way of working around that would be to remove the explicit declaration of the form field and simply handle this field separatly in your HTML template:
<input type="text" name="category" value="{{ form.initial.category.name }}" />
"Do you explicitly want a text input instead?" - No.
In that case, you want a ModelChoiceField instead of a CharField.
category = forms.ModelChoiceField(
queryset=Category.objects,
empty_label=None,
disabled=True, # Django 1.9+
initial=Category.objects.get(name='Zdrowie i uroda'))