Override field's name attribute?

[jacobsvante]

I need compatibility with some existing HTML that uses dashes in the name attribute, but I have yet to find a way to override it with wtforms. The documentation for wtforms.fields.core.Field mentions the following about _name:

The name of this field, passed by the enclosing form during its construction. You should never pass this value yourself.

This makes me think that I should be able to override the name in the enclosing form. But in that case - where? Here's a failing test that shows what I'm expecting to be able to do:

import wtforms
from werkzeug.datastructures import ImmutableMultiDict


class MyForm(wtforms.Form):
    my_field_id = wtforms.IntegerField('My field', id='my-field',
                                       _name='my-field')


my_data = ImmutableMultiDict([('my-field', '2')])
my_form = MyForm(my_data)
assert my_form.my_field_id.name == 'my-field'  # Instead `my_field_id`
assert my_form.my_field_id.data == 2  # Instead `None`

Instead I have to use this custom field to get what I'm looking for:

import wtforms
class MyCustomIntegerField(wtforms.IntegerField):

    def __init__(self, *args, **kwargs):
        name = kwargs.pop('name', None)
        super().__init__(*args, **kwargs)
        if name:
            self.name = name

Am I missing something here?

[jacobsvante]

I noticed this is mentioned in #154:

De-couple attribute names from field names
Allow users to have fields with names containing "special" characters while still allowing the field to >function, just like SQLAlchemy with attribute vs column names.
Default case (when attribute name unspecified) is still using attribute name munging for maximum >compatibility

Hopefully we can get it earlier though 😉

[xealot]

Just ran across this today when integrating with a third-party that requires special characters in the form submission. Primarily [ and ].

[crast]

Will be supported in 3.0 as you mentioned
#154

[bmwant]

@jmagnusson a workaround is to override form meta when binding a field.

from wtforms.meta import DefaultMeta

class BindNameMeta(DefaultMeta):
    def bind_field(self, form, unbound_field, options):
        if 'custom_name' in unbound_field.kwargs:
            options['name'] = unbound_field.kwargs.pop('custom_name')
        return unbound_field.bind(form=form, **options)

This allows you to provide a parameter custom_name to any field you want to override a name for.

class PostForm(Form):
    my_title = StringField(custom_name='my-title')

Just keep in mind that you have to subclass from your own Form that uses new meta:

import wtforms

class Form(wtforms.Form):
    meta = BindNameMeta

[pfubar]

thanks bmwant, i just needed to change meta to Meta.

import wtforms

class Form(wtforms.Form):
    Meta = BindNameMeta