Generated: Wed 2013-03-13 10:33 CET
Source file: /media/Envs/Envs/filer-gallery/lib/python2.7/site-packages/mptt/forms.py
Stats: 0 executed, 73 missed, 7 excluded, 99 ignored
"""
Form components for working with trees.
"""
from django import forms
from django.forms.forms import NON_FIELD_ERRORS
from django.forms.util import ErrorList
from django.utils.encoding import smart_unicode
from django.utils.html import conditional_escape, mark_safe
from django.utils.translation import ugettext_lazy as _
from mptt.exceptions import InvalidMove
__all__ = ('TreeNodeChoiceField', 'TreeNodeMultipleChoiceField', 'TreeNodePositionField', 'MoveNodeForm')
# Fields ######################################################################
class TreeNodeChoiceField(forms.ModelChoiceField):
"""A ModelChoiceField for tree nodes."""
def __init__(self, queryset, *args, **kwargs):
self.level_indicator = kwargs.pop('level_indicator', u'---')
if kwargs.get('required', True) and not 'empty_label' in kwargs:
kwargs['empty_label'] = None
# if a queryset is supplied, enforce ordering
if hasattr(queryset, 'model'):
mptt_opts = queryset.model._mptt_meta
queryset = queryset.order_by(mptt_opts.tree_id_attr, mptt_opts.left_attr)
super(TreeNodeChoiceField, self).__init__(queryset, *args, **kwargs)
def _get_level_indicator(self, obj):
level = getattr(obj, obj._mptt_meta.level_attr)
return mark_safe(conditional_escape(self.level_indicator) * level)
def label_from_instance(self, obj):
"""
Creates labels which represent the tree level of each node when
generating option labels.
"""
level_indicator = self._get_level_indicator(obj)
return mark_safe(u'%s %s' % (level_indicator, conditional_escape(smart_unicode(obj))))
class TreeNodeMultipleChoiceField(TreeNodeChoiceField, forms.ModelMultipleChoiceField):
"""A ModelMultipleChoiceField for tree nodes."""
def __init__(self, queryset, *args, **kwargs):
self.level_indicator = kwargs.pop('level_indicator', u'---')
if kwargs.get('required', True) and not 'empty_label' in kwargs:
kwargs['empty_label'] = None
# if a queryset is supplied, enforce ordering
if hasattr(queryset, 'model'):
mptt_opts = queryset.model._mptt_meta
queryset = queryset.order_by(mptt_opts.tree_id_attr, mptt_opts.left_attr)
# For some reason ModelMultipleChoiceField constructor passes kwargs
# as args to its super(), which causes 'multiple values for keyword arg'
# error sometimes. So we skip it (that constructor does nothing anyway!)
forms.ModelChoiceField.__init__(self, queryset, *args, **kwargs)
class TreeNodePositionField(forms.ChoiceField):
"""A ChoiceField for specifying position relative to another node."""
FIRST_CHILD = 'first-child'
LAST_CHILD = 'last-child'
LEFT = 'left'
RIGHT = 'right'
DEFAULT_CHOICES = (
(FIRST_CHILD, _('First child')),
(LAST_CHILD, _('Last child')),
(LEFT, _('Left sibling')),
(RIGHT, _('Right sibling')),
)
def __init__(self, *args, **kwargs):
if 'choices' not in kwargs:
kwargs['choices'] = self.DEFAULT_CHOICES
super(TreeNodePositionField, self).__init__(*args, **kwargs)
# Forms #######################################################################
class MoveNodeForm(forms.Form):
"""
A form which allows the user to move a given node from one location
in its tree to another, with optional restriction of the nodes which
are valid target nodes for the move.
"""
target = TreeNodeChoiceField(queryset=None)
position = TreeNodePositionField()
def __init__(self, node, *args, **kwargs):
"""
The ``node`` to be moved must be provided. The following keyword
arguments are also accepted::
``valid_targets``
Specifies a ``QuerySet`` of valid targets for the move. If
not provided, valid targets will consist of everything other
node of the same type, apart from the node itself and any
descendants.
For example, if you want to restrict the node to moving
within its own tree, pass a ``QuerySet`` containing
everything in the node's tree except itself and its
descendants (to prevent invalid moves) and the root node (as
a user could choose to make the node a sibling of the root
node).
``target_select_size``
The size of the select element used for the target node.
Defaults to ``10``.
``position_choices``
A tuple of allowed position choices and their descriptions.
Defaults to ``TreeNodePositionField.DEFAULT_CHOICES``.
``level_indicator``
A string which will be used to represent a single tree level
in the target options.
"""
self.node = node
valid_targets = kwargs.pop('valid_targets', None)
target_select_size = kwargs.pop('target_select_size', 10)
position_choices = kwargs.pop('position_choices', None)
level_indicator = kwargs.pop('level_indicator', None)
super(MoveNodeForm, self).__init__(*args, **kwargs)
opts = node._mptt_meta
if valid_targets is None:
valid_targets = node._tree_manager.exclude(**{
opts.tree_id_attr: getattr(node, opts.tree_id_attr),
'%s__gte' % opts.left_attr: getattr(node, opts.left_attr),
'%s__lte' % opts.right_attr: getattr(node, opts.right_attr),
})
self.fields['target'].queryset = valid_targets
self.fields['target'].widget.attrs['size'] = target_select_size
if level_indicator:
self.fields['target'].level_indicator = level_indicator
if position_choices:
self.fields['position_choices'].choices = position_choices
def save(self):
"""
Attempts to move the node using the selected target and
position.
If an invalid move is attempted, the related error message will
be added to the form's non-field errors and the error will be
re-raised. Callers should attempt to catch ``InvalidNode`` to
redisplay the form with the error, should it occur.
"""
try:
self.node.move_to(self.cleaned_data['target'],
self.cleaned_data['position'])
return self.node
except InvalidMove, e:
self.errors[NON_FIELD_ERRORS] = ErrorList(e)
raise
class MPTTAdminForm(forms.ModelForm):
"""
A form which validates that the chosen parent for a node isn't one of
it's descendants.
"""
def clean(self):
cleaned_data = super(MPTTAdminForm, self).clean()
opts = self._meta.model._mptt_meta
parent = cleaned_data.get(opts.parent_attr)
if self.instance and parent:
if parent.is_descendant_of(self.instance, include_self=True):
if opts.parent_attr not in self._errors:
self._errors[opts.parent_attr] = forms.util.ErrorList()
self._errors[opts.parent_attr].append(_('Invalid parent'))
del self.cleaned_data[opts.parent_attr]
return cleaned_data