import warnings
from enum import Enum
from wtforms import fields, validators
from sqlalchemy import Boolean, Column
from sqlalchemy.orm import ColumnProperty
from flask_admin import form
from flask_admin.model.form import (converts, ModelConverterBase,
InlineModelConverterBase, FieldPlaceholder)
from flask_admin.model.fields import AjaxSelectField, AjaxSelectMultipleField
from flask_admin.model.helpers import prettify_name
from flask_admin._backwards import get_property
from flask_admin._compat import iteritems, text_type
from .validators import Unique
from .fields import (QuerySelectField, QuerySelectMultipleField,
InlineModelFormList, InlineHstoreList, HstoreForm)
from flask_admin.model.fields import InlineFormField
from .tools import (has_multiple_pks, filter_foreign_columns,
get_field_with_path, is_association_proxy, is_relationship)
from .ajax import create_ajax_loader
class AdminModelConverter(ModelConverterBase):
"""
SQLAlchemy model to form converter
"""
def __init__(self, session, view):
super(AdminModelConverter, self).__init__()
self.session = session
self.view = view
def _get_label(self, name, field_args):
"""
Label for field name. If it is not specified explicitly,
then the views prettify_name method is used to find it.
:param field_args:
Dictionary with additional field arguments
"""
if 'label' in field_args:
return field_args['label']
column_labels = get_property(self.view, 'column_labels', 'rename_columns')
if column_labels:
return column_labels.get(name)
prettify_override = getattr(self.view, 'prettify_name', None)
if prettify_override:
return prettify_override(name)
return prettify_name(name)
def _get_description(self, name, field_args):
if 'description' in field_args:
return field_args['description']
column_descriptions = getattr(self.view, 'column_descriptions', None)
if column_descriptions:
return column_descriptions.get(name)
def _get_field_override(self, name):
form_overrides = getattr(self.view, 'form_overrides', None)
if form_overrides:
return form_overrides.get(name)
return None
def _model_select_field(self, prop, multiple, remote_model, **kwargs):
loader = getattr(self.view, '_form_ajax_refs', {}).get(prop.key)
if loader:
if multiple:
return AjaxSelectMultipleField(loader, **kwargs)
else:
return AjaxSelectField(loader, **kwargs)
if 'query_factory' not in kwargs:
kwargs['query_factory'] = lambda: self.session.query(remote_model)
if multiple:
return QuerySelectMultipleField(**kwargs)
else:
return QuerySelectField(**kwargs)
def _convert_relation(self, name, prop, property_is_association_proxy, kwargs):
# Check if relation is specified
form_columns = getattr(self.view, 'form_columns', None)
if form_columns and name not in form_columns:
return None
remote_model = prop.mapper.class_
column = prop.local_remote_pairs[0][0]
# If this relation points to local column that's not foreign key, assume
# that it is backref and use remote column data
if not column.foreign_keys:
column = prop.local_remote_pairs[0][1]
kwargs['label'] = self._get_label(name, kwargs)
kwargs['description'] = self._get_description(name, kwargs)
# determine optional/required, or respect existing
requirement_options = (validators.Optional, validators.InputRequired)
requirement_validator_specified = any(isinstance(v, requirement_options) for v in kwargs['validators'])
if property_is_association_proxy or column.nullable or prop.direction.name != 'MANYTOONE':
kwargs['allow_blank'] = True
if not requirement_validator_specified:
kwargs['validators'].append(validators.Optional())
else:
kwargs['allow_blank'] = False
if not requirement_validator_specified:
kwargs['validators'].append(validators.InputRequired())
# Override field type if necessary
override = self._get_field_override(prop.key)
if override:
return override(**kwargs)
multiple = (property_is_association_proxy or
(prop.direction.name in ('ONETOMANY', 'MANYTOMANY') and prop.uselist))
return self._model_select_field(prop, multiple, remote_model, **kwargs)
def convert(self, model, mapper, name, prop, field_args, hidden_pk):
# Properly handle forced fields
if isinstance(prop, FieldPlaceholder):
return form.recreate_field(prop.field)
kwargs = {
'validators': [],
'filters': []
}
if field_args:
kwargs.update(field_args)
if kwargs['validators']:
# Create a copy of the list since we will be modifying it.
kwargs['validators'] = list(kwargs['validators'])
# Check if it is relation or property
if hasattr(prop, 'direction') or is_association_proxy(prop):
property_is_association_proxy = is_association_proxy(prop)
if property_is_association_proxy:
if not hasattr(prop.remote_attr, 'prop'):
raise Exception('Association proxy referencing another association proxy is not supported.')
prop = prop.remote_attr.prop
return self._convert_relation(name, prop, property_is_association_proxy, kwargs)
elif hasattr(prop, 'columns'): # Ignore pk/fk
# Check if more than one column mapped to the property
if len(prop.columns) > 1 and not isinstance(prop, ColumnProperty):
columns = filter_foreign_columns(model.__table__, prop.columns)
if len(columns) == 0:
return None
elif len(columns) > 1:
warnings.warn('Can not convert multiple-column properties (%s.%s)' % (model, prop.key))
return None
column = columns[0]
else:
# Grab column
column = prop.columns[0]
form_columns = getattr(self.view, 'form_columns', None) or ()
# Do not display foreign keys - use relations, except when explicitly instructed
if column.foreign_keys and prop.key not in form_columns:
return None
# Only display "real" columns
if not isinstance(column, Column):
return None
unique = False
if column.primary_key:
if hidden_pk:
# If requested to add hidden field, show it
return fields.HiddenField()
else:
# By default, don't show primary keys either
# If PK is not explicitly allowed, ignore it
if prop.key not in form_columns:
return None
# Current Unique Validator does not work with multicolumns-pks
if not has_multiple_pks(model):
kwargs['validators'].append(Unique(self.session,
model,
column))
unique = True
# If field is unique, validate it
if column.unique and not unique:
kwargs['validators'].append(Unique(self.session,
model,
column))
optional_types = getattr(self.view, 'form_optional_types', (Boolean,))
if (
not column.nullable and
not isinstance(column.type, optional_types) and
not column.default and
not column.server_default
):
kwargs['validators'].append(validators.InputRequired())
# Apply label and description if it isn't inline form field
if self.view.model == mapper.class_:
kwargs['label'] = self._get_label(prop.key, kwargs)
kwargs['description'] = self._get_description(prop.key, kwargs)
# Figure out default value
default = getattr(column, 'default', None)
value = None
if default is not None:
value = getattr(default, 'arg', None)
if value is not None:
if getattr(default, 'is_callable', False):
value = lambda: default.arg(None) # noqa: E731
else:
if not getattr(default, 'is_scalar', True):
value = None
if value is not None:
kwargs['default'] = value
# Check nullable
if column.nullable:
kwargs['validators'].append(validators.Optional())
# Override field type if necessary
override = self._get_field_override(prop.key)
if override:
return override(**kwargs)
# Check choices
form_choices = getattr(self.view, 'form_choices', None)
if mapper.class_ == self.view.model and form_choices:
choices = form_choices.get(prop.key)
if choices:
return form.Select2Field(
choices=choices,
allow_blank=column.nullable,
**kwargs
)
# Run converter
converter = self.get_converter(column)
if converter is None:
return None
return converter(model=model, mapper=mapper, prop=prop,
column=column, field_args=kwargs)
return None
@classmethod
def _string_common(cls, column, field_args, **extra):
if hasattr(column.type, 'length') and isinstance(column.type.length, int) and column.type.length:
field_args['validators'].append(validators.Length(max=column.type.length))
@converts('String') # includes VARCHAR, CHAR, and Unicode
def conv_String(self, column, field_args, **extra):
if hasattr(column.type, 'enums'):
accepted_values = list(column.type.enums)
field_args['choices'] = [(f, f) for f in column.type.enums]
if column.nullable:
field_args['allow_blank'] = column.nullable
accepted_values.append(None)
field_args['validators'].append(validators.AnyOf(accepted_values))
field_args['coerce'] = lambda v: v.name if isinstance(v, Enum) else text_type(v)
return form.Select2Field(**field_args)
if column.nullable:
filters = field_args.get('filters', [])
filters.append(lambda x: x or None)
field_args['filters'] = filters
self._string_common(column=column, field_args=field_args, **extra)
return fields.StringField(**field_args)
@converts('Text', 'LargeBinary', 'Binary', 'CIText') # includes UnicodeText
def conv_Text(self, field_args, **extra):
self._string_common(field_args=field_args, **extra)
return fields.TextAreaField(**field_args)
@converts('Boolean', 'sqlalchemy.dialects.mssql.base.BIT')
def conv_Boolean(self, field_args, **extra):
return fields.BooleanField(**field_args)
@converts('Date')
def convert_date(self, field_args, **extra):
field_args['widget'] = form.DatePickerWidget()
return fields.DateField(**field_args)
@converts('DateTime') # includes TIMESTAMP
def convert_datetime(self, field_args, **extra):
return form.DateTimeField(**field_args)
@converts('Time')
def convert_time(self, field_args, **extra):
return form.TimeField(**field_args)
@converts('Integer') # includes BigInteger and SmallInteger
def handle_integer_types(self, column, field_args, **extra):
unsigned = getattr(column.type, 'unsigned', False)
if unsigned:
field_args['validators'].append(validators.NumberRange(min=0))
return fields.IntegerField(**field_args)
@converts('Numeric') # includes DECIMAL, Float/FLOAT, REAL, and DOUBLE
def handle_decimal_types(self, column, field_args, **extra):
# override default decimal places limit, use database defaults instead
field_args.setdefault('places', None)
return fields.DecimalField(**field_args)
@converts('sqlalchemy.dialects.postgresql.base.INET')
def conv_PGInet(self, field_args, **extra):
field_args.setdefault('label', u'IP Address')
field_args['validators'].append(validators.IPAddress())
return fields.StringField(**field_args)
@converts('sqlalchemy.dialects.postgresql.base.MACADDR')
def conv_PGMacaddr(self, field_args, **extra):
field_args.setdefault('label', u'MAC Address')
field_args['validators'].append(validators.MacAddress())
return fields.StringField(**field_args)
@converts('sqlalchemy.dialects.postgresql.base.UUID')
def conv_PGUuid(self, field_args, **extra):
field_args.setdefault('label', u'UUID')
field_args['validators'].append(validators.UUID())
return fields.StringField(**field_args)
@converts('sqlalchemy.dialects.postgresql.base.ARRAY',
'sqlalchemy.sql.sqltypes.ARRAY')
def conv_ARRAY(self, field_args, **extra):
return form.Select2TagsField(save_as_list=True, **field_args)
@converts('HSTORE')
def conv_HSTORE(self, field_args, **extra):
inner_form = field_args.pop('form', HstoreForm)
return InlineHstoreList(InlineFormField(inner_form), **field_args)
@converts('JSON')
def convert_JSON(self, field_args, **extra):
return form.JSONField(**field_args)
def _resolve_prop(prop):
"""
Resolve proxied property
:param prop:
Property to resolve
"""
# Try to see if it is proxied property
if hasattr(prop, '_proxied_property'):
return prop._proxied_property
return prop
# Get list of fields and generate form
def get_form(model, converter,
base_class=form.BaseForm,
only=None,
exclude=None,
field_args=None,
hidden_pk=False,
ignore_hidden=True,
extra_fields=None):
"""
Generate form from the model.
:param model:
Model to generate form from
:param converter:
Converter class to use
:param base_class:
Base form class
:param only:
Include fields
:param exclude:
Exclude fields
:param field_args:
Dictionary with additional field arguments
:param hidden_pk:
Generate hidden field with model primary key or not
:param ignore_hidden:
If set to True (default), will ignore properties that start with underscore
"""
# TODO: Support new 0.8 API
if not hasattr(model, '_sa_class_manager'):
raise TypeError('model must be a sqlalchemy mapped model')
mapper = model._sa_class_manager.mapper
field_args = field_args or {}
properties = ((p.key, p) for p in mapper.iterate_properties)
if only:
def find(name):
# If field is in extra_fields, it has higher priority
if extra_fields and name in extra_fields:
return name, FieldPlaceholder(extra_fields[name])
column, path = get_field_with_path(model, name, return_remote_proxy_attr=False)
if path and not (is_relationship(column) or is_association_proxy(column)):
raise Exception("form column is located in another table and "
"requires inline_models: {0}".format(name))
if is_association_proxy(column):
return name, column
relation_name = column.key
if column is not None and hasattr(column, 'property'):
return relation_name, column.property
raise ValueError('Invalid model property name %s.%s' % (model, name))
# Filter properties while maintaining property order in 'only' list
properties = (find(x) for x in only)
elif exclude:
properties = (x for x in properties if x[0] not in exclude)
field_dict = {}
for name, p in properties:
# Ignore protected properties
if ignore_hidden and name.startswith('_'):
continue
prop = _resolve_prop(p)
field = converter.convert(model, mapper, name, prop, field_args.get(name), hidden_pk)
if field is not None:
field_dict[name] = field
# Contribute extra fields
if not only and extra_fields:
for name, field in iteritems(extra_fields):
field_dict[name] = form.recreate_field(field)
return type(model.__name__ + 'Form', (base_class, ), field_dict)
class InlineModelConverter(InlineModelConverterBase):
"""
Inline model form helper.
"""
inline_field_list_type = InlineModelFormList
"""
Used field list type.
If you want to do some custom rendering of inline field lists,
you can create your own wtforms field and use it instead
"""
def __init__(self, session, view, model_converter):
"""
Constructor.
:param session:
SQLAlchemy session
:param view:
Flask-Admin view object
:param model_converter:
Model converter class. Will be automatically instantiated with
appropriate `InlineFormAdmin` instance.
"""
super(InlineModelConverter, self).__init__(view)
self.session = session
self.model_converter = model_converter
def get_info(self, p):
info = super(InlineModelConverter, self).get_info(p)
# Special case for model instances
if info is None:
if hasattr(p, '_sa_class_manager'):
return self.form_admin_class(p)
else:
model = getattr(p, 'model', None)
if model is None:
raise Exception('Unknown inline model admin: %s' % repr(p))
attrs = dict()
for attr in dir(p):
if not attr.startswith('_') and attr != 'model':
attrs[attr] = getattr(p, attr)
return self.form_admin_class(model, **attrs)
info = self.form_admin_class(model, **attrs)
# Resolve AJAX FKs
info._form_ajax_refs = self.process_ajax_refs(info)
return info
def process_ajax_refs(self, info):
refs = getattr(info, 'form_ajax_refs', None)
result = {}
if refs:
for name, opts in iteritems(refs):
new_name = '%s-%s' % (info.model.__name__.lower(), name)
loader = None
if isinstance(opts, dict):
loader = create_ajax_loader(info.model, self.session, new_name, name, opts)
else:
loader = opts
result[name] = loader
self.view._form_ajax_refs[new_name] = loader
return result
def _calculate_mapping_key_pair(self, model, info):
"""
Calculate mapping property key pair between `model` and inline model,
including the forward one for `model` and the reverse one for inline model.
Override the method to map your own inline models.
:param model:
Model class
:param info:
The InlineFormAdmin instance
:return:
A tuple of forward property key and reverse property key
"""
mapper = model._sa_class_manager.mapper
# Find property from target model to current model
# Use the base mapper to support inheritance
target_mapper = info.model._sa_class_manager.mapper.base_mapper
reverse_prop = None
for prop in target_mapper.iterate_properties:
if hasattr(prop, 'direction') and prop.direction.name in ('MANYTOONE', 'MANYTOMANY'):
if issubclass(model, prop.mapper.class_):
reverse_prop = prop
break
else:
raise Exception('Cannot find reverse relation for model %s' % info.model)
# Find forward property
forward_prop = None
if prop.direction.name == 'MANYTOONE':
candidate = 'ONETOMANY'
else:
candidate = 'MANYTOMANY'
for prop in mapper.iterate_properties:
if hasattr(prop, 'direction') and prop.direction.name == candidate:
if prop.mapper.class_ == target_mapper.class_:
forward_prop = prop
break
else:
raise Exception('Cannot find forward relation for model %s' % info.model)
return forward_prop.key, reverse_prop.key
def contribute(self, model, form_class, inline_model):
"""
Generate form fields for inline forms and contribute them to
the `form_class`
:param converter:
ModelConverterBase instance
:param session:
SQLAlchemy session
:param model:
Model class
:param form_class:
Form to add properties to
:param inline_model:
Inline model. Can be one of:
- ``tuple``, first value is related model instance,
second is dictionary with options
- ``InlineFormAdmin`` instance
- Model class
:return:
Form class
"""
info = self.get_info(inline_model)
forward_prop_key, reverse_prop_key = self._calculate_mapping_key_pair(model, info)
# Remove reverse property from the list
ignore = [reverse_prop_key]
if info.form_excluded_columns:
exclude = ignore + list(info.form_excluded_columns)
else:
exclude = ignore
# Create converter
converter = self.model_converter(self.session, info)
# Create form
child_form = info.get_form()
if child_form is None:
child_form = get_form(info.model,
converter,
base_class=info.form_base_class or form.BaseForm,
only=info.form_columns,
exclude=exclude,
field_args=info.form_args,
hidden_pk=True,
extra_fields=info.form_extra_fields)
# Post-process form
child_form = info.postprocess_form(child_form)
kwargs = dict()
label = self.get_label(info, forward_prop_key)
if label:
kwargs['label'] = label
if self.view.form_args:
field_args = self.view.form_args.get(forward_prop_key, {})
kwargs.update(**field_args)
# Contribute field
setattr(form_class,
forward_prop_key,
self.inline_field_list_type(child_form,
self.session,
info.model,
reverse_prop_key,
info,
**kwargs))
return form_class
