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, Attribute
  11 from philo.utils import fattr
  12
  13
  14 __all__ = ('EntityForm', )
  15
  16
  17 def proxy_fields_for_entity_model(entity_model, fields=None, exclude=None, widgets=None, formfield_callback=lambda f, **kwargs: f.formfield(**kwargs)):
  18         field_list = []
  19         ignored = []
  20         opts = entity_model._entity_meta
  21         for f in opts.proxy_fields:
  22                 if fields and not f.name in fields:
  23                         continue
  24                 if exclude and f.name in exclude:
  25                         continue
  26                 if widgets and f.name in widgets:
  27                         kwargs = {'widget': widgets[f.name]}
  28                 else:
  29                         kwargs = {}
  30                 formfield = formfield_callback(f, **kwargs)
  31                 if formfield:
  32                         field_list.append((f.name, formfield))
  33                 else:
  34                         ignored.append(f.name)
  35         field_dict = SortedDict(field_list)
  36         if fields:
  37                 field_dict = SortedDict(
  38                         [(f, field_dict.get(f)) for f in fields
  39                                 if ((not exclude) or (exclude and f not in exclude)) and (f not in ignored) and (f in field_dict)]
  40                 )
  41         return field_dict
  42
  43
  44 # BEGIN HACK - This will not be required after http://code.djangoproject.com/ticket/14082 has been resolved
  45
  46 class EntityFormBase(ModelForm):
  47         pass
  48
  49 _old_metaclass_new = ModelFormMetaclass.__new__
  50
  51 def _new_metaclass_new(cls, name, bases, attrs):
  52         new_class = _old_metaclass_new(cls, name, bases, attrs)
  53         if issubclass(new_class, EntityFormBase) and new_class._meta.model:
  54                 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
  55         return new_class
  56
  57 ModelFormMetaclass.__new__ = staticmethod(_new_metaclass_new)
  58
  59 # END HACK
  60
  61
  62 class EntityForm(EntityFormBase): # Would inherit from ModelForm directly if it weren't for the above HACK
  63         def __init__(self, *args, **kwargs):
  64                 initial = kwargs.pop('initial', None)
  65                 instance = kwargs.get('instance', None)
  66                 if instance is not None:
  67                         new_initial = {}
  68                         for f in instance._entity_meta.proxy_fields:
  69                                 if self._meta.fields and not f.name in self._meta.fields:
  70                                         continue
  71                                 if self._meta.exclude and f.name in self._meta.exclude:
  72                                         continue
  73                                 new_initial[f.name] = f.value_from_object(instance)
  74                 else:
  75                         new_initial = {}
  76                 if initial is not None:
  77                         new_initial.update(initial)
  78                 kwargs['initial'] = new_initial
  79                 super(EntityForm, self).__init__(*args, **kwargs)
  80
  81         @fattr(alters_data=True)
  82         def save(self, commit=True):
  83                 cleaned_data = self.cleaned_data
  84                 instance = super(EntityForm, self).save(commit=False)
  85
  86                 for f in instance._entity_meta.proxy_fields:
  87                         if self._meta.fields and f.name not in self._meta.fields:
  88                                 continue
  89                         setattr(instance, f.attname, cleaned_data[f.name])
  90
  91                 if commit:
  92                         instance.save()
  93                         self.save_m2m()
  94
  95                 return instance
  96
  97
  98 class AttributeForm(ModelForm):
  99         def __init__(self, *args, **kwargs):
 100                 super(AttributeForm, self).__init__(*args, **kwargs)
 101
 102                 # This is necessary because model forms store changes to self.instance in their clean method.
 103                 # Mutter mutter.
 104                 self._cached_value_ct = self.instance.value_content_type
 105                 self._cached_value = self.instance.value
 106
 107                 if self.instance.value is not None:
 108                         value_field = self.instance.value.value_formfield()
 109                         if value_field:
 110                                 self.fields['value'] = value_field
 111                         if hasattr(self.instance.value, 'content_type'):
 112                                 self.fields['content_type'] = self.instance.value._meta.get_field('content_type').formfield(initial=getattr(self.instance.value.content_type, 'pk', None))
 113
 114         def save(self, *args, **kwargs):
 115                 # At this point, the cleaned_data has already been stored on self.instance.
 116                 if self.instance.value_content_type != self._cached_value_ct:
 117                         if self.instance.value is not None:
 118                                 self._cached_value.delete()
 119                                 if 'value' in self.cleaned_data:
 120                                         del(self.cleaned_data['value'])
 121
 122                         if self.instance.value_content_type is not None:
 123                                 # Make a blank value of the new type! Run special code for content_type attributes.
 124                                 if hasattr(self.instance.value_content_type.model_class(), 'content_type'):
 125                                         if self._cached_value and hasattr(self._cached_value, 'content_type'):
 126                                                 new_ct = self._cached_value.content_type
 127                                         else:
 128                                                 new_ct = None
 129                                         new_value = self.instance.value_content_type.model_class().objects.create(content_type=new_ct)
 130                                 else:
 131                                         new_value = self.instance.value_content_type.model_class().objects.create()
 132
 133                                 new_value.apply_data(self.cleaned_data)
 134                                 new_value.save()
 135                                 self.instance.value = new_value
 136                 else:
 137                         # The value type is the same, but one of the fields has changed.
 138                         # Check to see if the changed value was the content type. We have to check the
 139                         # cleaned_data because self.instance.value.content_type was overridden.
 140                         if hasattr(self.instance.value, 'content_type') and 'content_type' in self.cleaned_data and 'value' in self.cleaned_data and (not hasattr(self._cached_value, 'content_type') or self._cached_value.content_type != self.cleaned_data['content_type']):
 141                                 self.cleaned_data['value'] = None
 142
 143                         self.instance.value.apply_data(self.cleaned_data)
 144                         self.instance.value.save()
 145
 146                 super(AttributeForm, self).save(*args, **kwargs)
 147                 return self.instance
 148
 149         class Meta:
 150                 model = Attribute
 151
 152
 153 class ContainerForm(ModelForm):
 154         def __init__(self, *args, **kwargs):
 155                 super(ContainerForm, self).__init__(*args, **kwargs)
 156                 self.verbose_name = self.instance.name.replace('_', ' ')
 157
 158
 159 class ContentletForm(ContainerForm):
 160         content = forms.CharField(required=False, widget=AdminTextareaWidget, label='Content')
 161
 162         def should_delete(self):
 163                 return not bool(self.cleaned_data['content'])
 164
 165         class Meta:
 166                 model = Contentlet
 167                 fields = ['name', 'content']
 168
 169
 170 class ContentReferenceForm(ContainerForm):
 171         def __init__(self, *args, **kwargs):
 172                 super(ContentReferenceForm, self).__init__(*args, **kwargs)
 173                 try:
 174                         self.fields['content_id'].widget = ModelLookupWidget(self.instance.content_type)
 175                 except ObjectDoesNotExist:
 176                         # This will happen when an empty form (which we will never use) gets instantiated.
 177                         pass
 178
 179         def should_delete(self):
 180                 return (self.cleaned_data['content_id'] is None)
 181
 182         class Meta:
 183                 model = ContentReference
 184                 fields = ['name', 'content_id']
 185
 186
 187 class ContainerInlineFormSet(BaseInlineFormSet):
 188         def __init__(self, containers, data=None, files=None, instance=None, save_as_new=False, prefix=None, queryset=None):
 189                 # Unfortunately, I need to add some things to BaseInline between its __init__ and its
 190                 # super call, so a lot of this is repetition.
 191
 192                 # Start cribbed from BaseInline
 193                 from django.db.models.fields.related import RelatedObject
 194                 self.save_as_new = save_as_new
 195                 # is there a better way to get the object descriptor?
 196                 self.rel_name = RelatedObject(self.fk.rel.to, self.model, self.fk).get_accessor_name()
 197                 if self.fk.rel.field_name == self.fk.rel.to._meta.pk.name:
 198                         backlink_value = self.instance
 199                 else:
 200                         backlink_value = getattr(self.instance, self.fk.rel.field_name)
 201                 if queryset is None:
 202                         queryset = self.model._default_manager
 203                 qs = queryset.filter(**{self.fk.name: backlink_value})
 204                 # End cribbed from BaseInline
 205
 206                 self.container_instances, qs = self.get_container_instances(containers, qs)
 207                 self.extra_containers = containers
 208                 self.extra = len(self.extra_containers)
 209                 super(BaseInlineFormSet, self).__init__(data, files, prefix=prefix, queryset=qs)
 210
 211         def get_container_instances(self, containers, qs):
 212                 raise NotImplementedError
 213
 214         def total_form_count(self):
 215                 if self.data or self.files:
 216                         return self.management_form.cleaned_data[TOTAL_FORM_COUNT]
 217                 else:
 218                         return self.initial_form_count() + self.extra
 219
 220         def save_existing_objects(self, commit=True):
 221                 self.changed_objects = []
 222                 self.deleted_objects = []
 223                 if not self.get_queryset():
 224                         return []
 225
 226                 saved_instances = []
 227                 for form in self.initial_forms:
 228                         pk_name = self._pk_field.name
 229                         raw_pk_value = form._raw_value(pk_name)
 230
 231                         # clean() for different types of PK fields can sometimes return
 232                         # the model instance, and sometimes the PK. Handle either.
 233                         pk_value = form.fields[pk_name].clean(raw_pk_value)
 234                         pk_value = getattr(pk_value, 'pk', pk_value)
 235
 236                         obj = self._existing_object(pk_value)
 237                         if form.should_delete():
 238                                 self.deleted_objects.append(obj)
 239                                 obj.delete()
 240                                 continue
 241                         if form.has_changed():
 242                                 self.changed_objects.append((obj, form.changed_data))
 243                                 saved_instances.append(self.save_existing(form, obj, commit=commit))
 244                                 if not commit:
 245                                         self.saved_forms.append(form)
 246                 return saved_instances
 247
 248         def save_new_objects(self, commit=True):
 249                 self.new_objects = []
 250                 for form in self.extra_forms:
 251                         if not form.has_changed():
 252                                 continue
 253                         # If someone has marked an add form for deletion, don't save the
 254                         # object.
 255                         if form.should_delete():
 256                                 continue
 257                         self.new_objects.append(self.save_new(form, commit=commit))
 258                         if not commit:
 259                                 self.saved_forms.append(form)
 260                 return self.new_objects
 261
 262
 263 class ContentletInlineFormSet(ContainerInlineFormSet):
 264         def __init__(self, data=None, files=None, instance=None, save_as_new=False, prefix=None, queryset=None):
 265                 if instance is None:
 266                         self.instance = self.fk.rel.to()
 267                 else:
 268                         self.instance = instance
 269
 270                 try:
 271                         containers = list(self.instance.containers[0])
 272                 except ObjectDoesNotExist:
 273                         containers = []
 274
 275                 super(ContentletInlineFormSet, self).__init__(containers, data, files, instance, save_as_new, prefix, queryset)
 276
 277         def get_container_instances(self, containers, qs):
 278                 qs = qs.filter(name__in=containers)
 279                 container_instances = []
 280                 for container in qs:
 281                         container_instances.append(container)
 282                         containers.remove(container.name)
 283                 return container_instances, qs
 284
 285         def _construct_form(self, i, **kwargs):
 286                 if i >= self.initial_form_count(): # and not kwargs.get('instance'):
 287                         kwargs['instance'] = self.model(name=self.extra_containers[i - self.initial_form_count() - 1])
 288
 289                 return super(ContentletInlineFormSet, self)._construct_form(i, **kwargs)
 290
 291
 292 class ContentReferenceInlineFormSet(ContainerInlineFormSet):
 293         def __init__(self, data=None, files=None, instance=None, save_as_new=False, prefix=None, queryset=None):
 294                 if instance is None:
 295                         self.instance = self.fk.rel.to()
 296                 else:
 297                         self.instance = instance
 298
 299                 try:
 300                         containers = list(self.instance.containers[1])
 301                 except ObjectDoesNotExist:
 302                         containers = []
 303
 304                 super(ContentReferenceInlineFormSet, self).__init__(containers, data, files, instance, save_as_new, prefix, queryset)
 305
 306         def get_container_instances(self, containers, qs):
 307                 filter = Q()
 308
 309                 for name, ct in containers:
 310                         filter |= Q(name=name, content_type=ct)
 311
 312                 qs = qs.filter(filter)
 313                 container_instances = []
 314                 for container in qs:
 315                         container_instances.append(container)
 316                         containers.remove((container.name, container.content_type))
 317                 return container_instances, qs
 318
 319         def _construct_form(self, i, **kwargs):
 320                 if i >= self.initial_form_count(): # and not kwargs.get('instance'):
 321                         name, content_type = self.extra_containers[i - self.initial_form_count() - 1]
 322                         kwargs['instance'] = self.model(name=name, content_type=content_type)
 323
 324                 return super(ContentReferenceInlineFormSet, self)._construct_form(i, **kwargs)