Unique field validator for SQLAlchemy forms.

Refactored code a bit.

flask_adminex/ext/fileadmin.py

@@ -16,7 +16,7 @@
 from flask.ext import wtf
 
 
-class NameForm(wtf.Form):
+class NameForm(form.BaseForm):
  """
  Form with a filename input field.
 
@@ -31,7 +31,7 @@ def validate_name(self, field):
  raise wtf.ValidationError('Invalid directory name')
 
 
-class UploadForm(form.AdminForm):
+class UploadForm(form.BaseForm):
  """
  File upload form. Works with FileAdmin instance to check if it is allowed
  to upload file with given extension.

flask_adminex/ext/sqlamodel.py

@@ -1,14 +1,47 @@
 from sqlalchemy.orm.attributes import InstrumentedAttribute
+from sqlalchemy.orm.exc import NoResultFound
 from sqlalchemy.sql.expression import desc
 
-from wtforms import fields
+from wtforms import ValidationError, fields
 from wtforms.ext.sqlalchemy.orm import model_form, converts, ModelConverter
 from wtforms.ext.sqlalchemy.fields import QuerySelectField, QuerySelectMultipleField
 
 from flask import flash
 
-from flask.ext.adminex.model import BaseModelView
-from flask.ext.adminex import form
+from flask.ext.adminex import model, form
+
+
+class Unique(object):
+ """Checks field value unicity against specified table field.
+
+ :param get_session:
+ A function that return a SQAlchemy Session.
+ :param model:
+ The model to check unicity against.
+ :param column:
+ The unique column.
+ :param message:
+ The error message.
+ """
+ field_flags = ('unique', )
+
+ def __init__(self, db_session, model, column, message=None):
+ self.db_session = db_session
+ self.model = model
+ self.column = column
+ self.message = message
+
+ def __call__(self, form, field):
+ try:
+ obj = (self.db_session.query(self.model)
+ .filter(self.column == field.data).one())
+
+ if not hasattr(form, '_obj') or not form._obj == obj:
+ if self.message is None:
+ self.message = field.gettext(u'Already exists.')
+ raise ValidationError(self.message)
+ except NoResultFound:
+ pass
 
 
 class AdminModelConverter(ModelConverter):
@@ -30,37 +63,39 @@ def _get_label(self, name, field_args):
  return None
 
  def convert(self, model, mapper, prop, field_args):
- if not field_args:
- field_args = dict()
+ kwargs = {
+ 'validators': [],
+ 'filters': []
+ }
+
+ if field_args:
+ kwargs.update(field_args)
 
  if hasattr(prop, 'direction'):
  remote_model = prop.mapper.class_
  local_column = prop.local_remote_pairs[0][0]
 
- kwargs = {
- 'validators': [],
- 'filters': [],
+ kwargs.update({
  'allow_blank': local_column.nullable,
- 'label': self._get_label(prop.key, field_args),
- 'query_factory': lambda: self.view.session.query(remote_model),
- 'default': None
- }
-
- if field_args:
- kwargs.update(field_args)
+ 'label': self._get_label(prop.key, kwargs),
+ 'query_factory': lambda: self.view.session.query(remote_model)
+ })
 
  if prop.direction.name == 'MANYTOONE':
- return QuerySelectField(widget=form.ChosenSelectWidget(), **kwargs)
+ return QuerySelectField(widget=form.ChosenSelectWidget(),
+ **kwargs)
  elif prop.direction.name == 'ONETOMANY':
  # Skip backrefs
  if not local_column.foreign_keys and self.view.hide_backrefs:
  return None
 
- return QuerySelectMultipleField(widget=form.ChosenSelectWidget(multiple=True),
- **kwargs)
+ return QuerySelectMultipleField(
+ widget=form.ChosenSelectWidget(multiple=True),
+ **kwargs)
  elif prop.direction.name == 'MANYTOMANY':
- return QuerySelectMultipleField(widget=form.ChosenSelectWidget(multiple=True),
- **kwargs)
+ return QuerySelectMultipleField(
+ widget=form.ChosenSelectWidget(multiple=True),
+ **kwargs)
  else:
  # Ignore pk/fk
  if hasattr(prop, 'columns'):
@@ -69,12 +104,19 @@ def convert(self, model, mapper, prop, field_args):
  if column.foreign_keys or column.primary_key:
  return None
 
- field_args['label'] = self._get_label(prop.key, field_args)
+ # If field is unique, validate it
+ if column.unique:
+ kwargs['validators'].append(Unique(self.view.session,
+ model,
+ column))
+
+ # Apply label
+ kwargs['label'] = self._get_label(prop.key, kwargs)
 
  return super(AdminModelConverter, self).convert(model,
  mapper,
  prop,
- field_args)
+ kwargs)
 
  @converts('Date')
  def convert_date(self, field_args, **extra):
@@ -91,7 +133,7 @@ def convert_time(self, field_args, **extra):
  return form.TimeField(**field_args)
 
 
-class ModelView(BaseModelView):
+class ModelView(model.BaseModelView):
  """
  SQLALchemy model view
 
@@ -166,7 +208,8 @@ def scaffold_sortable_columns(self):
  # Sanity check
  if len(p.columns) > 1:
  raise Exception('Automatic form scaffolding is not supported' +
- ' for multi-column properties (%s.%s)' % (self.model.__name__, p.key))
+ ' for multi-column properties (%s.%s)' % (
+ self.model.__name__, p.key))
 
  column = p.columns[0]
 
@@ -183,7 +226,7 @@ def scaffold_form(self):
  Create form from the model.
  """
  return model_form(self.model,
- form.AdminForm,
+ form.BaseForm,
  self.form_columns,
  field_args=self.form_args,
  converter=AdminModelConverter(self))

flask_adminex/form.py

@@ -5,10 +5,14 @@
 from wtforms import fields, widgets
 
 
-class AdminForm(wtf.Form):
+class BaseForm(wtf.Form):
  """
  Customized form class.
  """
+ def __init__(self, formdata=None, obj=None, prefix='', **kwargs):
+ super(BaseForm, self).__init__(formdata, obj, prefix, **kwargs)
+
+ self._obj = obj
 
  @property
  def has_file_field(self):

flask_adminex/model.py

@@ -227,7 +227,7 @@ def get_sortable_columns(self):
 
  def scaffold_form(self):
  """
- Create `form.AdminForm` class from the model. Must be implemented in
+ Create `form.BaseForm` inherited class from the model. Must be implemented in
  the child class.
  """
  raise NotImplemented('Please implement scaffold_form method')