Django, ModelChoiceField() and initial value

I'm using something like this:

field1 = forms.ModelChoiceField(queryset=...)

How can I make my form show the a value as selected?

If you want to set the default initial value you should be defining initial like other form fields except you set it to the id instead.

Say you've got field1 like this:

class YourForm(forms.Form):
    field1 = forms.ModelChoiceField(queryset = MyModel.objects.all() )

then you need to set initial when you create your form like this:

form = YourForm(initial = {'field1': instance_of_mymodel.pk })

rather than:

form = YourForm(initial = {'field1': instance_of_mymodel })

I'm also assuming you've defined __unicode__ for your models so this displays correctly.

You can just use

 field1 = forms.ModelChoiceField(queryset=..., initial=0) 

to make the first value selected etc. It's more generic way, then the other answer.

The times they have changed:

The default initial value can now be set by defining initial like other form fields except you set it to the id instead.

Now this will suffice:

form = YourForm(initial = {'field1': instance_of_mymodel })

Though both still work.

The code

form = YourForm(initial = {'field1': instance_of_mymodel.pk })

and

form = YourForm(initial = {'field1': instance_of_mymodel })

or initial field directly following:

field1 = forms.ModelChoiceField(queryset=..., initial=0) 

All work.

The first two ways will override the final way.

field1 = forms.ModelChoiceField(queryset=Model.objects.all(), empty_label="Selected value")

It's as simple as that....!

Just want to add this answer after stumbling on this question. I know it works on Django 3.2, at least. If you have some calculated value in the __init__ method, you can do this to set the initial value at instantiation as well:

def __init__(self, value, *args, **kwargs):
    # super call, etc.
    self.do_something(value)
    self.fields['field'].initial = value

If the form does multiple things with value, it's a bit more DRY to pass it only once instead of redundantly with the initial kwarg in instantiation.

You could do this as well:

form = YourForm(initial = {'field1': pk })

if you are parsing your primary key through a query string or via an ajax call no need for an instance, the query set has already handled that for your drop down, the pk indexes the state you want