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Django Rest Framework serializer field style argument

So I'm migrating some apps from DRF 2.4 to DRF 3.1. One of the changes that has been made is for serializer fields widget is no longer an valid argument. Instead we need to use style which according to the documentation expects a dict with key value pairs representing how the field is to be rendered. The example they give is:
# Use <input type="password"> for the input.
password = serializers.CharField(
style={'input_type': 'password'}
)
# Use a radio input instead of a select input.
color_channel = serializers.ChoiceField(
choices=['red', 'green', 'blue']
style = {'base_template': 'radio.html'}
}
This makes sense but what I am not seeing anywhere is where we find the valid values of base_template and input_type. For example if I wanted to make a field rendered as checkboxes how would I do that? What I am looking for is some documentation on what the API can accept and I'm not finding it anywhere. I feel kind of stupid asking this since it seems like it should be easy to find. Could anyone enlighten me? Am I just missing something obvious here? Any advice would be appreciated. Thanks!

I wanted to replace a select by a text input for a foreign key field, but likewise found only a few examples in the docs, e.g. http://www.django-rest-framework.org/topics/3.0-announcement/#the-style-keyword-argument-for-serializer-fields
Thanks to the debug toolbar, I could find out the default style for each serializer field and the actual location on disk: From there, I could look at the source directory to see the available values.

Use widget attribute do define form field type:
*Like THis *
code = serializers.CharField(widget=forms.Textarea())
You're probably using DRF v2.x.x, which doesn't support style argument in Field class

Duplicate/Archive entry in Django to another model

I have been at this for Two days and I'm now hoping someone can point me in the right direction. All I am trying to do is duplicate an entry in a table/model into another model with mirrored fields, essentially creating an archived version. I want this to happen when the user calls the update view.
What I have tried so far is setting pk to None and then trying to find a way to move the previous version to the mirrored/archive model. After a couple of hours of research I gave up on this path. Next I thought the answer would lie with the pre_save receiver but I can't find a way to access the model instance to then save that to the archive model.
#receiver(pre_save, sender=InstrumentAnnual)
def archive_calc_instance(sender, instance, **kwargs):
stored_id = getattr(instance, 'id', None)
e = InstrumentAnnual.objects.filter(id = stored_id)
archive = InstrumentAnnualArchive(e.field_name, e.another_field_name...)
archive.save()
As far as I can tell this should work however e only contains the First field from the model.
Is there something that can be done with this code to achieve my goal or is there a more 'Django' way to solve this? I.e. some sort of official archive feature?
Thanks in advance.

With the help of #Igor's comment I amended my solution to this:
def archive_calc(self, object_id):
annual = InstrumentAnnual.objects.get(id = object_id)
annual_archive = InstrumentAnnualArchive()
for field in annual._meta.fields:
setattr(annual_archive, field.name, getattr(annual, field.name))
annual_archive.pk = None
annual_archive.save()
It occured to me that using pre_save wouldn't work as it is listening/linked to a model, not a view as I originally thought. So I placed the above code in my Update View and called it passing the id in object_id.
Thanks again for the help.

You should be using named arguments in your constructor, otherwise the first argument will be interpreted as the id, so try:
# omitted code
e = InstrumentAnnual.objects.filter(id=stored_id)
archive = InstrumentalAnnualArchive(field_name=e.field_name, another_name=e.another_field_name, …)
archive.save()
But you could also use Django's create function, so:
# omitted code
e = InstrumentAnnual.objects.filter(id=stored_id)
archive = InstrumentalAnnualArchive.objects.create(field_name=e.field_name, another_name=e.another_field_name, …)
This way handles the save for you, so you don't need to explicitly save your object.

How to properly validate a MultipleChoiceField in a Django form

I have a MultipleChoiceField representing US states, and passing a GET request to my form like ?state=AL%2CAK results in the error:
Select a valid choice. AL,AK is not one of the available choices.
However, these values are definitely listed in the fields choices, as they're rendered in the form field correctly.
I've tried specifying a custom clean_state() method in my form, to convert the value to a list, but that has no effect. Printing the cleaned_data['state'] seems to show it's not even being called with the data from request.GET.
What's causing this error?
from django import forms
class MyForm(forms.Form):
state = forms.MultipleChoiceField(
required=False,
choices=[('AL','Alabama'),('AK','Alaska')],
)

MultipleChoiceFields don't pass all of the selected values in a list, they pass several different values for the same key instead.
In other words, if you select 'AL' and 'AK' your querystring should be ?state=AL&state=AK instead of ?state=AL%2CAK.
Without seeing your custom clean_state() method I can't tell you what's going wrong with it, but if the state field isn't valid because the querystring is wrong then 'state' won't be in cleaned_data (because cleaned_data only holds valid data).
Hopefully that helps. If you're still stuck try adding a few more details and I can try to be more specific.

Pass an entire inital object in an edit form (data pre-population) in Django

I have a very complicated form and I choose to not use ModelForm since I needed flexibility and control over the fields. Since I am not using ModelForm, I can't simply do something like instance=order, where order = Order.objects.get(pk=1).
Currently I am pre-populating every field with initial in the forms.py as oppose to the views.py like this
self.fields['work_type'] = forms.ChoiceField(choices=Order.WORK_TYPE_CHOICES, initial=order.work_type)
But I was wondering if I could pass the entire order object to a form or do I have to declare initial to every field?
Is there a way to do something like
order_form = OrderEditForm(data=request.POST, initial=order)
in views.py?

I have a very complicated form and I choose to not use ModelForm since
I needed flexibility and control over the fields
Everything that you can do using a Form, you can do in a ModelForm such as adding new fields or over-riding attributes on the fields etc.
But I was wondering if I could pass the entire order object to a form
or do I have to declare initial to every field?
You can pass the order object into the form but you will still have to populate each field individually either in the forms or in the view function.
So in your view you would do something like this:
intial = {'order_number': order.number, 'order_id': order.id}
form = OrderForm(initial=initial)

The easiest way to prepopulate data to a form is passing a dictionary as first argument to de form constructor.
order_form = OrderEditForm(order.__dict__())
where __dict__() is a method that passes "order" object attributes to a dictionary with each attribute's name as a key and their content as value.
An example of how to "invent" such a method could be something like:
order_initial = Order.objects.filter(pk=order.pk).values()[0]
and then construct the form with:
order_form = OrderEditForm(order_initial)
Look at this example (how they populate values at "post" time):

For future reference to other people:
I have since found out after reading SO's comments and answers that it's better to use ModelForm even if you end up explicitly defining every field manually (using something like self.fields['foo'] = forms.CharField()).
In any case, if you are trying to pass a dictionary of current values in a form then the best (built-in) way to convert a model to a dictionary is actually using model_to_dict:
from django.forms.models import model_to_dict
order = Order.objects.get(pk=1)
dictionary = model_to_dict(order)
form = OrderEditForm(dictionary)
I got the solution from this blog. I hope this will be helpful for someone.

Add an "empty" option to a ChoiceField based on model datas

I'm defining a ChoiceField based on a model's datas.
field = forms.ChoiceField(choices=[[r.id, r.name] for r in Model.objects.all()])
However I'd like to prepend my options with an empty one to select "no" objects.
But I can't find a nice way to prepend that.
All my tests like :
field = forms.ChoiceField(choices=[[0, '----------']].extend([[r.id, r.name] for r in Model.objects.all()]))
Returns me a "NoneType object not iterable" error.
The only way I've found until now is the following :
def append_empty(choices):
ret = [[0, '----------']]
for c in choices:
ret.append(c)
return ret
And when I define my field :
forms.ChoiceField(choices=append_empty([[r.id, r.name] for r in
Restaurant.objects.all()]), required=False)
However I'd like to keep my code clean and not have that kind of horrors.
Would you have an idea for me ? :p
Thanks by advance.

An easy answer is to do:
field = forms.ChoiceField(choices=[[0, '----------']] + [[r.id, r.name] for r in Model.objects.all()])
Unfortunately, your approach is flawed. Even with your 'working' approach, the field choices are defined when the form is defined, not when it is instantiated - so if you add elements to the Model table, they will not appear in the choices list.
You can avoid this by doing the allocation in the __init__ method of your Form.
However, there is a much easier approach. Rather than messing about with field choices dynamically, you should use the field that is specifically designed to provide choices from a model - ModelChoiceField. Not only does this get the list of model elements dynamically at instantiation, it already includes a blank choice by default. See the documentation.

Since this question and its answer almost solved a problem I just had I'd like to add something. For me, the id had to be empty because the model didn't recognise '0' as a valid option, but it accepted empty (null=True, blank=True). In the initializer:
self.fields['option_field'].choices = [
('', '------')] + [[r.id, r.name] for r in Model.objects.all()]