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.forms.models import model_to_dict, fields_for_model, ModelFormMetaclass, ModelForm, BaseInlineFormSet
   5 from django.forms.formsets import TOTAL_FORM_COUNT
   6 from django.template import loader, loader_tags, TemplateDoesNotExist, Context, Template as DjangoTemplate
   7 from django.utils.datastructures import SortedDict
   8 from philo.admin.widgets import ModelLookupWidget
   9 from philo.models import Entity, Template, Contentlet, ContentReference
  10 from philo.models.fields import RelationshipField
  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 def validate_template(template):
  99         """
 100         Makes sure that the template and all included or extended templates are valid.
 101         """
 102         for node in template.nodelist:
 103                 try:
 104                         if isinstance(node, loader_tags.ExtendsNode):
 105                                 extended_template = node.get_parent(Context())
 106                                 validate_template(extended_template)
 107                         elif isinstance(node, loader_tags.IncludeNode):
 108                                 included_template = loader.get_template(node.template_name.resolve(Context()))
 109                                 validate_template(extended_template)
 110                 except Exception, e:
 111                         raise ValidationError("Template code invalid. Error was: %s: %s" % (e.__class__.__name__, e))
 112
 113
 114 class TemplateForm(ModelForm):
 115         def clean_code(self):
 116                 code = self.cleaned_data['code']
 117                 try:
 118                         t = DjangoTemplate(code)
 119                 except Exception, e:
 120                         raise ValidationError("Template code invalid. Error was: %s: %s" % (e.__class__.__name__, e))
 121
 122                 validate_template(t)
 123                 return code
 124
 125         class Meta:
 126                 model = Template
 127
 128
 129 class ContainerForm(ModelForm):
 130         def __init__(self, *args, **kwargs):
 131                 super(ContainerForm, self).__init__(*args, **kwargs)
 132                 self.verbose_name = self.instance.name.replace('_', ' ')
 133
 134
 135 class ContentletForm(ContainerForm):
 136         content = forms.CharField(required=False, widget=AdminTextareaWidget)
 137
 138         def should_delete(self):
 139                 return not bool(self.cleaned_data['content'])
 140
 141         class Meta:
 142                 model = Contentlet
 143                 fields = ['name', 'content', 'dynamic']
 144
 145
 146 class ContentReferenceForm(ContainerForm):
 147         def __init__(self, *args, **kwargs):
 148                 super(ContentReferenceForm, self).__init__(*args, **kwargs)
 149                 try:
 150                         self.fields['content_id'].widget = ModelLookupWidget(self.instance.content_type)
 151                 except ObjectDoesNotExist:
 152                         # This will happen when an empty form (which we will never use) gets instantiated.
 153                         pass
 154
 155         def should_delete(self):
 156                 return (self.cleaned_data['content_id'] is None)
 157
 158         class Meta:
 159                 model = ContentReference
 160                 fields = ['name', 'content_id']
 161
 162
 163 class ContainerInlineFormSet(BaseInlineFormSet):
 164         def __init__(self, containers, data=None, files=None, instance=None, save_as_new=False, prefix=None, queryset=None):
 165                 # Unfortunately, I need to add some things to BaseInline between its __init__ and its super call, so
 166                 # a lot of this is repetition.
 167
 168                 # Start cribbed from BaseInline
 169                 from django.db.models.fields.related import RelatedObject
 170                 self.save_as_new = save_as_new
 171                 # is there a better way to get the object descriptor?
 172                 self.rel_name = RelatedObject(self.fk.rel.to, self.model, self.fk).get_accessor_name()
 173                 if self.fk.rel.field_name == self.fk.rel.to._meta.pk.name:
 174                         backlink_value = self.instance
 175                 else:
 176                         backlink_value = getattr(self.instance, self.fk.rel.field_name)
 177                 if queryset is None:
 178                         queryset = self.model._default_manager
 179                 qs = queryset.filter(**{self.fk.name: backlink_value})
 180                 # End cribbed from BaseInline
 181
 182                 self.container_instances, qs = self.get_container_instances(containers, qs)
 183                 self.extra_containers = containers
 184                 self.extra = len(self.extra_containers)
 185                 super(BaseInlineFormSet, self).__init__(data, files, prefix=prefix, queryset=qs)
 186
 187         def get_container_instances(self, containers, qs):
 188                 raise NotImplementedError
 189
 190         def total_form_count(self):
 191                 if self.data or self.files:
 192                         return self.management_form.cleaned_data[TOTAL_FORM_COUNT]
 193                 else:
 194                         return self.initial_form_count() + self.extra
 195
 196         def save_existing_objects(self, commit=True):
 197                 self.changed_objects = []
 198                 self.deleted_objects = []
 199                 if not self.get_queryset():
 200                         return []
 201
 202                 saved_instances = []
 203                 for form in self.initial_forms:
 204                         pk_name = self._pk_field.name
 205                         raw_pk_value = form._raw_value(pk_name)
 206
 207                         # clean() for different types of PK fields can sometimes return
 208                         # the model instance, and sometimes the PK. Handle either.
 209                         pk_value = form.fields[pk_name].clean(raw_pk_value)
 210                         pk_value = getattr(pk_value, 'pk', pk_value)
 211
 212                         obj = self._existing_object(pk_value)
 213                         if form.should_delete():
 214                                 self.deleted_objects.append(obj)
 215                                 obj.delete()
 216                                 continue
 217                         if form.has_changed():
 218                                 self.changed_objects.append((obj, form.changed_data))
 219                                 saved_instances.append(self.save_existing(form, obj, commit=commit))
 220                                 if not commit:
 221                                         self.saved_forms.append(form)
 222                 return saved_instances
 223
 224         def save_new_objects(self, commit=True):
 225                 self.new_objects = []
 226                 for form in self.extra_forms:
 227                         if not form.has_changed():
 228                                 continue
 229                         # If someone has marked an add form for deletion, don't save the
 230                         # object.
 231                         if form.should_delete():
 232                                 continue
 233                         self.new_objects.append(self.save_new(form, commit=commit))
 234                         if not commit:
 235                                 self.saved_forms.append(form)
 236                 return self.new_objects
 237
 238
 239 class ContentletInlineFormSet(ContainerInlineFormSet):
 240         def __init__(self, data=None, files=None, instance=None, save_as_new=False, prefix=None, queryset=None):
 241                 if instance is None:
 242                         self.instance = self.fk.rel.to()
 243                 else:
 244                         self.instance = instance
 245
 246                 try:
 247                         containers = list(self.instance.containers[0])
 248                 except ObjectDoesNotExist:
 249                         containers = []
 250
 251                 super(ContentletInlineFormSet, self).__init__(containers, data, files, instance, save_as_new, prefix, queryset)
 252
 253         def get_container_instances(self, containers, qs):
 254                 qs = qs.filter(name__in=containers)
 255                 container_instances = []
 256                 for container in qs:
 257                         container_instances.append(container)
 258                         containers.remove(container.name)
 259                 return container_instances, qs
 260
 261         def _construct_form(self, i, **kwargs):
 262                 if i >= self.initial_form_count(): # and not kwargs.get('instance'):
 263                         kwargs['instance'] = self.model(name=self.extra_containers[i - self.initial_form_count() - 1])
 264
 265                 return super(ContentletInlineFormSet, self)._construct_form(i, **kwargs)
 266
 267
 268 class ContentReferenceInlineFormSet(ContainerInlineFormSet):
 269         def __init__(self, data=None, files=None, instance=None, save_as_new=False, prefix=None, queryset=None):
 270                 if instance is None:
 271                         self.instance = self.fk.rel.to()
 272                 else:
 273                         self.instance = instance
 274
 275                 try:
 276                         containers = list(self.instance.containers[1])
 277                 except ObjectDoesNotExist:
 278                         containers = []
 279
 280                 super(ContentReferenceInlineFormSet, self).__init__(containers, data, files, instance, save_as_new, prefix, queryset)
 281
 282         def get_container_instances(self, containers, qs):
 283                 qs = qs.filter(name__in=[c[0] for c in containers])
 284                 container_instances = []
 285                 for container in qs:
 286                         container_instances.append(container)
 287                         containers.remove((container.name, container.content_type))
 288                 return container_instances, qs
 289
 290         def _construct_form(self, i, **kwargs):
 291                 if i >= self.initial_form_count(): # and not kwargs.get('instance'):
 292                         name, content_type = self.extra_containers[i - self.initial_form_count() - 1]
 293                         kwargs['instance'] = self.model(name=name, content_type=content_type)
 294
 295                 return super(ContentReferenceInlineFormSet, self)._construct_form(i, **kwargs)