Source code for flask_admin.contrib.sqla.fields

"""
    Useful form fields for use with SQLAlchemy ORM.
"""
import operator

from wtforms.fields import SelectFieldBase, StringField
from wtforms.validators import ValidationError

try:
    from wtforms.fields import _unset_value as unset_value
except ImportError:
    from wtforms.utils import unset_value

from .tools import get_primary_key
from flask_admin._compat import text_type, string_types, iteritems
from flask_admin.contrib.sqla.widgets import CheckboxListInput
from flask_admin.form import FormOpts, BaseForm, Select2Widget
from flask_admin.model.fields import InlineFieldList, InlineModelFormField
from flask_admin.babel import lazy_gettext

try:
    from sqlalchemy.orm.util import identity_key
    has_identity_key = True
except ImportError:
    has_identity_key = False


[docs]class QuerySelectField(SelectFieldBase): """ Will display a select drop-down field to choose between ORM results in a sqlalchemy `Query`. The `data` property actually will store/keep an ORM model instance, not the ID. Submitting a choice which is not in the query will result in a validation error. This field only works for queries on models whose primary key column(s) have a consistent string representation. This means it mostly only works for those composed of string, unicode, and integer types. For the most part, the primary keys will be auto-detected from the model, alternately pass a one-argument callable to `get_pk` which can return a unique comparable key. The `query` property on the field can be set from within a view to assign a query per-instance to the field. If the property is not set, the `query_factory` callable passed to the field constructor will be called to obtain a query. Specify `get_label` to customize the label associated with each option. If a string, this is the name of an attribute on the model object to use as the label text. If a one-argument callable, this callable will be passed model instance and expected to return the label text. Otherwise, the model object's `__str__` or `__unicode__` will be used. If `allow_blank` is set to `True`, then a blank choice will be added to the top of the list. Selecting this choice will result in the `data` property being `None`. The label for this blank choice can be set by specifying the `blank_text` parameter. """ widget = Select2Widget() def __init__(self, label=None, validators=None, query_factory=None, get_pk=None, get_label=None, allow_blank=False, blank_text=u'', **kwargs): super(QuerySelectField, self).__init__(label, validators, **kwargs) self.query_factory = query_factory if get_pk is None: if not has_identity_key: raise Exception(u'The sqlalchemy identity_key function could not be imported.') self.get_pk = get_pk_from_identity else: self.get_pk = get_pk if get_label is None: self.get_label = lambda x: x elif isinstance(get_label, string_types): self.get_label = operator.attrgetter(get_label) else: self.get_label = get_label self.allow_blank = allow_blank self.blank_text = blank_text self.query = None self._object_list = None def _get_data(self): if self._formdata is not None: for pk, obj in self._get_object_list(): if pk == self._formdata: self._set_data(obj) break return self._data def _set_data(self, data): self._data = data self._formdata = None data = property(_get_data, _set_data) def _get_object_list(self): if self._object_list is None: query = self.query or self.query_factory() get_pk = self.get_pk self._object_list = [(text_type(get_pk(obj)), obj) for obj in query] return self._object_list def iter_choices(self): if self.allow_blank: yield (u'__None', self.blank_text, self.data is None) for pk, obj in self._get_object_list(): yield (pk, self.get_label(obj), obj == self.data) def process_formdata(self, valuelist): if valuelist: if self.allow_blank and valuelist[0] == u'__None': self.data = None else: self._data = None self._formdata = valuelist[0] def pre_validate(self, form): if not self.allow_blank or self.data is not None: for pk, obj in self._get_object_list(): if self.data == obj: break else: raise ValidationError(self.gettext(u'Not a valid choice'))
[docs]class QuerySelectMultipleField(QuerySelectField): """ Very similar to QuerySelectField with the difference that this will display a multiple select. The data property will hold a list with ORM model instances and will be an empty list when no value is selected. If any of the items in the data list or submitted form data cannot be found in the query, this will result in a validation error. """ widget = Select2Widget(multiple=True) def __init__(self, label=None, validators=None, default=None, **kwargs): if default is None: default = [] super(QuerySelectMultipleField, self).__init__(label, validators, default=default, **kwargs) self._invalid_formdata = False def _get_data(self): formdata = self._formdata if formdata is not None: data = [] for pk, obj in self._get_object_list(): if not formdata: break elif pk in formdata: formdata.remove(pk) data.append(obj) if formdata: self._invalid_formdata = True self._set_data(data) return self._data def _set_data(self, data): self._data = data self._formdata = None data = property(_get_data, _set_data) def iter_choices(self): for pk, obj in self._get_object_list(): yield (pk, self.get_label(obj), obj in self.data) def process_formdata(self, valuelist): self._formdata = set(valuelist) def pre_validate(self, form): if self._invalid_formdata: raise ValidationError(self.gettext(u'Not a valid choice')) elif self.data: obj_list = list(x[1] for x in self._get_object_list()) for v in self.data: if v not in obj_list: raise ValidationError(self.gettext(u'Not a valid choice'))
[docs]class CheckboxListField(QuerySelectMultipleField): """ Alternative field for many-to-many relationships. Can be used instead of `QuerySelectMultipleField`. Appears as the list of checkboxes. Example:: class MyView(ModelView): form_columns = ( 'languages', ) form_args = { 'languages': { 'query_factory': Language.query, }, } form_overrides = { 'languages': CheckboxListField, } """ widget = CheckboxListInput()
class HstoreForm(BaseForm): """ Form used in InlineFormField/InlineHstoreList for HSTORE columns """ key = StringField(lazy_gettext('Key')) value = StringField(lazy_gettext('Value')) class KeyValue(object): """ Used by InlineHstoreList to simulate a key and a value field instead of the single HSTORE column. """ def __init__(self, key=None, value=None): self.key = key self.value = value class InlineHstoreList(InlineFieldList): """ Version of InlineFieldList for use with Postgres HSTORE columns """ def process(self, formdata, data=unset_value): """ SQLAlchemy returns a dict for HSTORE columns, but WTForms cannot process a dict. This overrides `process` to convert the dict returned by SQLAlchemy to a list of classes before processing. """ if isinstance(data, dict): data = [KeyValue(k, v) for k, v in iteritems(data)] super(InlineHstoreList, self).process(formdata, data) def populate_obj(self, obj, name): """ Combines each FormField key/value into a dictionary for storage """ _fake = type(str('_fake'), (object, ), {}) output = {} for form_field in self.entries: if not self.should_delete(form_field): fake_obj = _fake() fake_obj.data = KeyValue() form_field.populate_obj(fake_obj, 'data') output[fake_obj.data.key] = fake_obj.data.value setattr(obj, name, output) class InlineModelFormList(InlineFieldList): """ Customized inline model form list field. """ form_field_type = InlineModelFormField """ Form field type. Override to use custom field for each inline form """ def __init__(self, form, session, model, prop, inline_view, **kwargs): """ Default constructor. :param form: Form for the related model :param session: SQLAlchemy session :param model: Related model :param prop: Related property name :param inline_view: Inline view """ self.form = form self.session = session self.model = model self.prop = prop self.inline_view = inline_view self._pk = get_primary_key(model) # Generate inline form field form_opts = FormOpts(widget_args=getattr(inline_view, 'form_widget_args', None), form_rules=inline_view._form_rules) form_field = self.form_field_type(form, self._pk, form_opts=form_opts) super(InlineModelFormList, self).__init__(form_field, **kwargs) def display_row_controls(self, field): return field.get_pk() is not None def populate_obj(self, obj, name): values = getattr(obj, name, None) if values is None: return # Create primary key map pk_map = dict((get_obj_pk(v, self._pk), v) for v in values) # Handle request data for field in self.entries: field_id = get_field_id(field) is_created = field_id not in pk_map if not is_created: model = pk_map[field_id] if self.should_delete(field): self.session.delete(model) continue else: model = self.model() values.append(model) field.populate_obj(model, None) self.inline_view._on_model_change(field, model, is_created) def get_pk_from_identity(obj): # TODO: Remove me key = identity_key(instance=obj)[1] return u':'.join(text_type(x) for x in key) def get_obj_pk(obj, pk): """ get and format pk from obj :rtype: text_type """ if isinstance(pk, tuple): return tuple(text_type(getattr(obj, k)) for k in pk) return text_type(getattr(obj, pk)) def get_field_id(field): """ get and format id from field :rtype: text_type """ field_id = field.get_pk() if isinstance(field_id, tuple): return tuple(text_type(_) for _ in field_id) return text_type(field_id)