3.2.1 - AttributeError: 'tuple' object has no attribute 'items'

[macmule]

This was originally logged as: pallets-eco/flask-admin#2546

I hit an issue with a couple of my Flask-Admin applications, and can recreate in the attached example.

The issue is that when clicking "Create" or "Edit" Flask-Admin errors with the below traceback:

[2024-10-22 10:11:46 +0100] [73] [ERROR] Error handling request /admin/definitions/new/?url=/admin/definitions/
Traceback (most recent call last):
  File "/usr/local/lib/python3.10/dist-packages/gunicorn/workers/gthread.py", line 282, in handle
    keepalive = self.handle_request(req, conn)
  File "/usr/local/lib/python3.10/dist-packages/gunicorn/workers/gthread.py", line 334, in handle_request
    respiter = self.wsgi(environ, resp.start_response)
  File "/usr/local/lib/python3.10/dist-packages/flask/app.py", line 2552, in __call__
    return self.wsgi_app(environ, start_response)
  File "/usr/local/lib/python3.10/dist-packages/flask/app.py", line 2532, in wsgi_app
    response = self.handle_exception(e)
  File "/usr/local/lib/python3.10/dist-packages/flask/app.py", line 2529, in wsgi_app
    response = self.full_dispatch_request()
  File "/usr/local/lib/python3.10/dist-packages/flask/app.py", line 1825, in full_dispatch_request
    rv = self.handle_user_exception(e)
  File "/usr/local/lib/python3.10/dist-packages/flask/app.py", line 1823, in full_dispatch_request
    rv = self.dispatch_request()
  File "/usr/local/lib/python3.10/dist-packages/flask/app.py", line 1799, in dispatch_request
    return self.ensure_sync(self.view_functions[rule.endpoint])(**view_args)
  File "/usr/local/lib/python3.10/dist-packages/flask_admin/base.py", line 69, in inner
    return self._run_view(f, *args, **kwargs)
  File "/usr/local/lib/python3.10/dist-packages/flask_admin/base.py", line 369, in _run_view
    return fn(self, *args, **kwargs)
  File "/usr/local/lib/python3.10/dist-packages/flask_admin/model/base.py", line 2093, in create_view
    form = self.create_form()
  File "/usr/local/lib/python3.10/dist-packages/flask_admin/model/base.py", line 1332, in create_form
    return self._create_form_class(get_form_data(), obj=obj)
  File "/usr/local/lib/python3.10/dist-packages/wtforms/form.py", line 209, in __call__
    return type.__call__(cls, *args, **kwargs)
  File "/usr/local/lib/python3.10/dist-packages/flask_admin/form/__init__.py", line 22, in __init__
    super(BaseForm, self).__init__(formdata=formdata, obj=obj, prefix=prefix, **kwargs)
  File "/usr/local/lib/python3.10/dist-packages/wtforms/form.py", line 281, in __init__
    super().__init__(self._unbound_fields, meta=meta_obj, prefix=prefix)
  File "/usr/local/lib/python3.10/dist-packages/wtforms/form.py", line 49, in __init__
    field = meta.bind_field(self, unbound_field, options)
  File "/usr/local/lib/python3.10/dist-packages/wtforms/meta.py", line 28, in bind_field
    return unbound_field.bind(form=form, **options)
  File "/usr/local/lib/python3.10/dist-packages/wtforms/fields/core.py", line 387, in bind
    return self.field_class(*self.args, **kw)
  File "/usr/local/lib/python3.10/dist-packages/wtforms/fields/core.py", line 133, in __init__
    for k, v in flags.items():
AttributeError: 'tuple' object has no attribute 'items'

To recreate:

1. Download the follwoing .zip: Flask-Admin-Test.zip
2. Double click run.command (check contents of that script 1st.. it's just setting things up to test).
3. Once completed, navigate in a browser to: http://127.0.0.1:8000/
4. Click the "Create" option text.
5. BOOM.. Internal Server Error.. and terminal output will show the same as I've posted in this thread.

The resolution:

Pinning WTForms to 3.1.2 resolved the issue, (3.2.0 errored with ImportError: cannot import name 'SelectFieldBase' from 'wtforms.fields').

[davidism]

Flask-Admin will need to update to be compatible with the new WTForms feature release. You should reopen that original issue.

[azmeuk]

For the record @macmule, flask-admin uses tuple flags, but they have been deprecated 4 years ago in favor of dict flags (with #467) and the deprecated code have been removed with 3.2 (with #859).

[macmule]

@azmeuk thanks for the extra information.. so that would be why then :)

I have reopened the issue in the flask-admin repo.