forms.py

   1 from django import forms
   2 from django.contrib.admin.widgets import AdminTextareaWidget
   3 from django.core.exceptions import ValidationError, ObjectDoesNotExist
   4 from django.db.models import Q
   5 from django.forms.models import model_to_dict, fields_for_model, ModelFormMetaclass, ModelForm, BaseInlineFormSet
   6 from django.forms.formsets import TOTAL_FORM_COUNT
   7 from django.template import loader, loader_tags, TemplateDoesNotExist, Context, Template as DjangoTemplate
   8 from django.utils.datastructures import SortedDict
   9 from philo.admin.widgets import ModelLookupWidget
  10 from philo.models import Entity, Template, Contentlet, ContentReference
  11 from philo.models.fields import RelationshipField
  12 from philo.utils import fattr
  13
  14
  15 __all__ = ('EntityForm', )
  16
  17
  18 def proxy_fields_for_entity_model(entity_model, fields=None, exclude=None, widgets=None, formfield_callback=lambda f, **kwargs: f.formfield(**kwargs)):
  19         field_list = []
  20         ignored = []
  21         opts = entity_model._entity_meta
  22         for f in opts.proxy_fields:
  23                 if fields and not f.name in fields:
  24                         continue
  25                 if exclude and f.name in exclude:
  26                         continue
  27                 if widgets and f.name in widgets:
  28                         kwargs = {'widget': widgets[f.name]}
  29                 else:
  30                         kwargs = {}
  31                 formfield = formfield_callback(f, **kwargs)
  32                 if formfield:
  33                         field_list.append((f.name, formfield))
  34                 else:
  35                         ignored.append(f.name)
  36         field_dict = SortedDict(field_list)
  37         if fields:
  38                 field_dict = SortedDict(
  39                         [(f, field_dict.get(f)) for f in fields
  40                                 if ((not exclude) or (exclude and f not in exclude)) and (f not in ignored) and (f in field_dict)]
  41                 )
  42         return field_dict
  43
  44
  45 # BEGIN HACK - This will not be required after http://code.djangoproject.com/ticket/14082 has been resolved
  46
  47 class EntityFormBase(ModelForm):
  48         pass
  49
  50 _old_metaclass_new = ModelFormMetaclass.__new__
  51
  52 def _new_metaclass_new(cls, name, bases, attrs):
  53         new_class = _old_metaclass_new(cls, name, bases, attrs)
  54         if issubclass(new_class, EntityFormBase) and new_class._meta.model:
  55                 new_class.base_fields.update(proxy_fields_for_entity_model(new_class._meta.model, new_class._meta.fields, new_class._meta.exclude, new_class._meta.widgets)) # don't pass in formfield_callback
  56         return new_class
  57
  58 ModelFormMetaclass.__new__ = staticmethod(_new_metaclass_new)
  59
  60 # END HACK
  61
  62
  63 class EntityForm(EntityFormBase): # Would inherit from ModelForm directly if it weren't for the above HACK
  64         def __init__(self, *args, **kwargs):
  65                 initial = kwargs.pop('initial', None)
  66                 instance = kwargs.get('instance', None)
  67                 if instance is not None:
  68                         new_initial = {}
  69                         for f in instance._entity_meta.proxy_fields:
  70                                 if self._meta.fields and not f.name in self._meta.fields:
  71                                         continue
  72                                 if self._meta.exclude and f.name in self._meta.exclude:
  73                                         continue
  74                                 new_initial[f.name] = f.value_from_object(instance)
  75                 else:
  76                         new_initial = {}
  77                 if initial is not None:
  78                         new_initial.update(initial)
  79                 kwargs['initial'] = new_initial
  80                 super(EntityForm, self).__init__(*args, **kwargs)
  81
  82         @fattr(alters_data=True)
  83         def save(self, commit=True):
  84                 cleaned_data = self.cleaned_data
  85                 instance = super(EntityForm, self).save(commit=False)
  86
  87                 for f in instance._entity_meta.proxy_fields:
  88                         if self._meta.fields and f.name not in self._meta.fields:
  89                                 continue
  90                         setattr(instance, f.attname, cleaned_data[f.name])
  91
  92                 if commit:
  93                         instance.save()
  94                         self.save_m2m()
  95
  96                 return instance
  97
  98
  99 def validate_template(template):
 100         """
 101         Makes sure that the template and all included or extended templates are valid.
 102         """
 103         for node in template.nodelist:
 104                 try:
 105                         if isinstance(node, loader_tags.ExtendsNode):
 106                                 extended_template = node.get_parent(Context())
 107                                 validate_template(extended_template)
 108                         elif isinstance(node, loader_tags.IncludeNode):
 109                                 included_template = loader.get_template(node.template_name.resolve(Context()))
 110                                 validate_template(extended_template)
 111                 except Exception, e:
 112                         raise ValidationError("Template code invalid. Error was: %s: %s" % (e.__class__.__name__, e))
 113
 114
 115 class TemplateForm(ModelForm):
 116         def clean_code(self):
 117                 code = self.cleaned_data['code']
 118                 try:
 119                         t = DjangoTemplate(code)
 120                 except Exception, e:
 121                         raise ValidationError("Template code invalid. Error was: %s: %s" % (e.__class__.__name__, e))
 122
 123                 validate_template(t)
 124                 return code
 125
 126         class Meta:
 127                 model = Template
 128
 129
 130 class ContainerForm(ModelForm):
 131         def __init__(self, *args, **kwargs):
 132                 super(ContainerForm, self).__init__(*args, **kwargs)
 133                 self.verbose_name = self.instance.name.replace('_', ' ')
 134
 135
 136 class ContentletForm(ContainerForm):
 137         content = forms.CharField(required=False, widget=AdminTextareaWidget)
 138
 139         def should_delete(self):
 140                 return not bool(self.cleaned_data['content'])
 141
 142         class Meta:
 143                 model = Contentlet
 144                 fields = ['name', 'content', 'dynamic']
 145
 146
 147 class ContentReferenceForm(ContainerForm):
 148         def __init__(self, *args, **kwargs):
 149                 super(ContentReferenceForm, self).__init__(*args, **kwargs)
 150                 try:
 151                         self.fields['content_id'].widget = ModelLookupWidget(self.instance.content_type)
 152                 except ObjectDoesNotExist:
 153                         # This will happen when an empty form (which we will never use) gets instantiated.
 154                         pass
 155
 156         def should_delete(self):
 157                 return (self.cleaned_data['content_id'] is None)
 158
 159         class Meta:
 160                 model = ContentReference
 161                 fields = ['name', 'content_id']
 162
 163
 164 class ContainerInlineFormSet(BaseInlineFormSet):
 165         def __init__(self, containers, data=None, files=None, instance=None, save_as_new=False, prefix=None, queryset=None):
 166                 # Unfortunately, I need to add some things to BaseInline between its __init__ and its super call, so
 167                 # a lot of this is repetition.
 168
 169                 # Start cribbed from BaseInline
 170                 from django.db.models.fields.related import RelatedObject
 171                 self.save_as_new = save_as_new
 172                 # is there a better way to get the object descriptor?
 173                 self.rel_name = RelatedObject(self.fk.rel.to, self.model, self.fk).get_accessor_name()
 174                 if self.fk.rel.field_name == self.fk.rel.to._meta.pk.name:
 175                         backlink_value = self.instance
 176                 else:
 177                         backlink_value = getattr(self.instance, self.fk.rel.field_name)
 178                 if queryset is None:
 179                         queryset = self.model._default_manager
 180                 qs = queryset.filter(**{self.fk.name: backlink_value})
 181                 # End cribbed from BaseInline
 182
 183                 self.container_instances, qs = self.get_container_instances(containers, qs)
 184                 self.extra_containers = containers
 185                 self.extra = len(self.extra_containers)
 186                 super(BaseInlineFormSet, self).__init__(data, files, prefix=prefix, queryset=qs)
 187
 188         def get_container_instances(self, containers, qs):
 189                 raise NotImplementedError
 190
 191         def total_form_count(self):
 192                 if self.data or self.files:
 193                         return self.management_form.cleaned_data[TOTAL_FORM_COUNT]
 194                 else:
 195                         return self.initial_form_count() + self.extra
 196
 197         def save_existing_objects(self, commit=True):
 198                 self.changed_objects = []
 199                 self.deleted_objects = []
 200                 if not self.get_queryset():
 201                         return []
 202
 203                 saved_instances = []
 204                 for form in self.initial_forms:
 205                         pk_name = self._pk_field.name
 206                         raw_pk_value = form._raw_value(pk_name)
 207
 208                         # clean() for different types of PK fields can sometimes return
 209                         # the model instance, and sometimes the PK. Handle either.
 210                         pk_value = form.fields[pk_name].clean(raw_pk_value)
 211                         pk_value = getattr(pk_value, 'pk', pk_value)
 212
 213                         obj = self._existing_object(pk_value)
 214                         if form.should_delete():
 215                                 self.deleted_objects.append(obj)
 216                                 obj.delete()
 217                                 continue
 218                         if form.has_changed():
 219                                 self.changed_objects.append((obj, form.changed_data))
 220                                 saved_instances.append(self.save_existing(form, obj, commit=commit))
 221                                 if not commit:
 222                                         self.saved_forms.append(form)
 223                 return saved_instances
 224
 225         def save_new_objects(self, commit=True):
 226                 self.new_objects = []
 227                 for form in self.extra_forms:
 228                         if not form.has_changed():
 229                                 continue
 230                         # If someone has marked an add form for deletion, don't save the
 231                         # object.
 232                         if form.should_delete():
 233                                 continue
 234                         self.new_objects.append(self.save_new(form, commit=commit))
 235                         if not commit:
 236                                 self.saved_forms.append(form)
 237                 return self.new_objects
 238
 239
 240 class ContentletInlineFormSet(ContainerInlineFormSet):
 241         def __init__(self, data=None, files=None, instance=None, save_as_new=False, prefix=None, queryset=None):
 242                 if instance is None:
 243                         self.instance = self.fk.rel.to()
 244                 else:
 245                         self.instance = instance
 246
 247                 try:
 248                         containers = list(self.instance.containers[0])
 249                 except ObjectDoesNotExist:
 250                         containers = []
 251
 252                 super(ContentletInlineFormSet, self).__init__(containers, data, files, instance, save_as_new, prefix, queryset)
 253
 254         def get_container_instances(self, containers, qs):
 255                 qs = qs.filter(name__in=containers)
 256                 container_instances = []
 257                 for container in qs:
 258                         container_instances.append(container)
 259                         containers.remove(container.name)
 260                 return container_instances, qs
 261
 262         def _construct_form(self, i, **kwargs):
 263                 if i >= self.initial_form_count(): # and not kwargs.get('instance'):
 264                         kwargs['instance'] = self.model(name=self.extra_containers[i - self.initial_form_count() - 1])
 265
 266                 return super(ContentletInlineFormSet, self)._construct_form(i, **kwargs)
 267
 268
 269 class ContentReferenceInlineFormSet(ContainerInlineFormSet):
 270         def __init__(self, data=None, files=None, instance=None, save_as_new=False, prefix=None, queryset=None):
 271                 if instance is None:
 272                         self.instance = self.fk.rel.to()
 273                 else:
 274                         self.instance = instance
 275
 276                 try:
 277                         containers = list(self.instance.containers[1])
 278                 except ObjectDoesNotExist:
 279                         containers = []
 280
 281                 super(ContentReferenceInlineFormSet, self).__init__(containers, data, files, instance, save_as_new, prefix, queryset)
 282
 283         def get_container_instances(self, containers, qs):
 284                 filter = Q()
 285
 286                 for name, ct in containers:
 287                         filter |= Q(name=name, content_type=ct)
 288
 289                 qs = qs.filter(filter)
 290                 container_instances = []
 291                 for container in qs:
 292                         container_instances.append(container)
 293                         containers.remove((container.name, container.content_type))
 294                 return container_instances, qs
 295
 296         def _construct_form(self, i, **kwargs):
 297                 if i >= self.initial_form_count(): # and not kwargs.get('instance'):
 298                         name, content_type = self.extra_containers[i - self.initial_form_count() - 1]
 299                         kwargs['instance'] = self.model(name=name, content_type=content_type)
 300
 301                 return super(ContentReferenceInlineFormSet, self)._construct_form(i, **kwargs)