Closes #14740: Remove BootstrapMixin (#14841)

* Introduce custom form widget templates to apply CSS classes

* Apply both mandatory and optional CSS classes to form widgets

* Omit required & placeholder attrs

* Move annotation of field validation failures to CSS

* Remove BootstrapMixin class

* Remove obsolete ComponentTemplateImportForm class

* Remove obsolete custom forms for login & password change

* Clean up obsolete accommodations for 'required' widget attr

netbox/utilities/forms/mixins.py

@@ -3,68 +3,11 @@ import time
 from django import forms
 from django.utils.translation import gettext_lazy as _
 
-from .widgets import APISelect, APISelectMultiple, ClearableFileInput
-
 __all__ = (
-    'BootstrapMixin',
     'CheckLastUpdatedMixin',
 )
 
 
-class BootstrapMixin:
-    """
-    Add the base Bootstrap CSS classes to form elements.
-    """
-    def __init__(self, *args, **kwargs):
-        super().__init__(*args, **kwargs)
-
-        exempt_widgets = [
-            forms.FileInput,
-            forms.RadioSelect,
-            APISelect,
-            APISelectMultiple,
-            ClearableFileInput,
-        ]
-
-        for field_name, field in self.fields.items():
-            css = field.widget.attrs.get('class', '')
-
-            if field.widget.__class__ in exempt_widgets:
-                continue
-
-            elif isinstance(field.widget, forms.CheckboxInput):
-                field.widget.attrs['class'] = f'{css} form-check-input'
-
-            elif isinstance(field.widget, forms.SelectMultiple) and 'size' in field.widget.attrs:
-                # Use native Bootstrap class for multi-line <select> widgets
-                field.widget.attrs['class'] = f'{css} form-select form-select-sm'
-
-            elif isinstance(field.widget, (forms.Select, forms.SelectMultiple)):
-                field.widget.attrs['class'] = f'{css} netbox-static-select'
-
-            else:
-                field.widget.attrs['class'] = f'{css} form-control'
-
-            if field.required and not isinstance(field.widget, forms.FileInput):
-                field.widget.attrs['required'] = 'required'
-
-            if 'placeholder' not in field.widget.attrs and field.label is not None:
-                field.widget.attrs['placeholder'] = field.label
-
-    def is_valid(self):
-        is_valid = super().is_valid()
-
-        # Apply is-invalid CSS class to fields with errors
-        if not is_valid:
-            for field_name in self.errors:
-                # Ignore e.g. __all__
-                if field := self.fields.get(field_name):
-                    css = field.widget.attrs.get('class', '')
-                    field.widget.attrs['class'] = f'{css} is-invalid'
-
-        return is_valid
-
-
 class CheckLastUpdatedMixin(forms.Form):
     """
     Checks whether the object being saved has been updated since the form was initialized. If so, validation fails.