Create Form with pre-defined set of fields

[lingster]

Hi,
Is it possible to create a form which is programmatically pre-defined with a set of fields. I'd like to ensure that my forms always has at least 1 input text box, but I'm stuggling to see how to add this.

[ababic]

@lingster you could do this by overriding the base_form_class on the Form model, and setting an initial value for fields in the __init__ method, but it would be nicer to be able to swap out the form model completely, then you could simply override __init__ on your custom model.

[lingster]

@ababic : indeed this is roughly what I have tried:

class MyPageForm(WagtailAdminModelForm):
    def clean(self):
       # my custom code 

class MyForm(AbstractForm):
    base_form_class = MyPageForm
    def __init__(self):
      ....
    
@modeladmin_register
class MyFormModelAdmin(FormModelAdmin):
    model = MyForm

The trouble with this method is that we will now have additional table created to store MyForm. I'm just looking for a cleaner way to implement this, could you do something like Form.base_form_class = MyPageForm instead?

[ababic]

could you do something like Form.base_form_class = MyPageForm instead?

This is the approach I have taken in a recent project.

[lingster]

Yes, that does indeed do the trick. I can add some documentation for this, if it will be useful for future users?
Perhaps a new forms.rst ?