python/lib/django_1_4/django/contrib/databrowse/datastructures.py

   1 """
   2 These classes are light wrappers around Django's database API that provide
   3 convenience functionality and permalink functions for the databrowse app.
   4 """
   5
   6 from django.db import models
   7 from django.utils import formats
   8 from django.utils.text import capfirst
   9 from django.utils.encoding import smart_unicode, smart_str, iri_to_uri
  10 from django.utils.safestring import mark_safe
  11 from django.db.models.query import QuerySet
  12
  13 EMPTY_VALUE = '(None)'
  14 DISPLAY_SIZE = 100
  15
  16 class EasyModel(object):
  17     def __init__(self, site, model):
  18         self.site = site
  19         self.model = model
  20         self.model_list = site.registry.keys()
  21         self.verbose_name = model._meta.verbose_name
  22         self.verbose_name_plural = model._meta.verbose_name_plural
  23
  24     def __repr__(self):
  25         return '<EasyModel for %s>' % smart_str(self.model._meta.object_name)
  26
  27     def model_databrowse(self):
  28         "Returns the ModelDatabrowse class for this model."
  29         return self.site.registry[self.model]
  30
  31     def url(self):
  32         return mark_safe('%s%s/%s/' % (self.site.root_url, self.model._meta.app_label, self.model._meta.module_name))
  33
  34     def objects(self, **kwargs):
  35         return self.get_query_set().filter(**kwargs)
  36
  37     def get_query_set(self):
  38         easy_qs = self.model._default_manager.get_query_set()._clone(klass=EasyQuerySet)
  39         easy_qs._easymodel = self
  40         return easy_qs
  41
  42     def object_by_pk(self, pk):
  43         return EasyInstance(self, self.model._default_manager.get(pk=pk))
  44
  45     def sample_objects(self):
  46         for obj in self.model._default_manager.all()[:3]:
  47             yield EasyInstance(self, obj)
  48
  49     def field(self, name):
  50         try:
  51             f = self.model._meta.get_field(name)
  52         except models.FieldDoesNotExist:
  53             return None
  54         return EasyField(self, f)
  55
  56     def fields(self):
  57         return [EasyField(self, f) for f in (self.model._meta.fields + self.model._meta.many_to_many)]
  58
  59 class EasyField(object):
  60     def __init__(self, easy_model, field):
  61         self.model, self.field = easy_model, field
  62
  63     def __repr__(self):
  64         return smart_str(u'<EasyField for %s.%s>' % (self.model.model._meta.object_name, self.field.name))
  65
  66     def choices(self):
  67         for value, label in self.field.choices:
  68             yield EasyChoice(self.model, self, value, label)
  69
  70     def url(self):
  71         if self.field.choices:
  72             return mark_safe('%s%s/%s/%s/' % (self.model.site.root_url, self.model.model._meta.app_label, self.model.model._meta.module_name, self.field.name))
  73         elif self.field.rel:
  74             return mark_safe('%s%s/%s/' % (self.model.site.root_url, self.model.model._meta.app_label, self.model.model._meta.module_name))
  75
  76 class EasyChoice(object):
  77     def __init__(self, easy_model, field, value, label):
  78         self.model, self.field = easy_model, field
  79         self.value, self.label = value, label
  80
  81     def __repr__(self):
  82         return smart_str(u'<EasyChoice for %s.%s>' % (self.model.model._meta.object_name, self.field.name))
  83
  84     def url(self):
  85         return mark_safe('%s%s/%s/%s/%s/' % (self.model.site.root_url, self.model.model._meta.app_label, self.model.model._meta.module_name, self.field.field.name, iri_to_uri(self.value)))
  86
  87 class EasyInstance(object):
  88     def __init__(self, easy_model, instance):
  89         self.model, self.instance = easy_model, instance
  90
  91     def __repr__(self):
  92         return smart_str(u'<EasyInstance for %s (%s)>' % (self.model.model._meta.object_name, self.instance._get_pk_val()))
  93
  94     def __unicode__(self):
  95         val = smart_unicode(self.instance)
  96         if len(val) > DISPLAY_SIZE:
  97             return val[:DISPLAY_SIZE] + u'...'
  98         return val
  99
 100     def __str__(self):
 101         return self.__unicode__().encode('utf-8')
 102
 103     def pk(self):
 104         return self.instance._get_pk_val()
 105
 106     def url(self):
 107         return mark_safe('%s%s/%s/objects/%s/' % (self.model.site.root_url, self.model.model._meta.app_label, self.model.model._meta.module_name, iri_to_uri(self.pk())))
 108
 109     def fields(self):
 110         """
 111         Generator that yields EasyInstanceFields for each field in this
 112         EasyInstance's model.
 113         """
 114         for f in self.model.model._meta.fields + self.model.model._meta.many_to_many:
 115             yield EasyInstanceField(self.model, self, f)
 116
 117     def related_objects(self):
 118         """
 119         Generator that yields dictionaries of all models that have this
 120         EasyInstance's model as a ForeignKey or ManyToManyField, along with
 121         lists of related objects.
 122         """
 123         for rel_object in self.model.model._meta.get_all_related_objects() + self.model.model._meta.get_all_related_many_to_many_objects():
 124             if rel_object.model not in self.model.model_list:
 125                 continue # Skip models that aren't in the model_list
 126             em = EasyModel(self.model.site, rel_object.model)
 127             yield {
 128                 'model': em,
 129                 'related_field': rel_object.field.verbose_name,
 130                 'object_list': [EasyInstance(em, i) for i in getattr(self.instance, rel_object.get_accessor_name()).all()],
 131             }
 132
 133 class EasyInstanceField(object):
 134     def __init__(self, easy_model, instance, field):
 135         self.model, self.field, self.instance = easy_model, field, instance
 136         self.raw_value = getattr(instance.instance, field.name)
 137
 138     def __repr__(self):
 139         return smart_str(u'<EasyInstanceField for %s.%s>' % (self.model.model._meta.object_name, self.field.name))
 140
 141     def values(self):
 142         """
 143         Returns a list of values for this field for this instance. It's a list
 144         so we can accomodate many-to-many fields.
 145         """
 146         # This import is deliberately inside the function because it causes
 147         # some settings to be imported, and we don't want to do that at the
 148         # module level.
 149         if self.field.rel:
 150             if isinstance(self.field.rel, models.ManyToOneRel):
 151                 objs = getattr(self.instance.instance, self.field.name)
 152             elif isinstance(self.field.rel, models.ManyToManyRel): # ManyToManyRel
 153                 return list(getattr(self.instance.instance, self.field.name).all())
 154         elif self.field.choices:
 155             objs = dict(self.field.choices).get(self.raw_value, EMPTY_VALUE)
 156         elif isinstance(self.field, models.DateField) or isinstance(self.field, models.TimeField):
 157             if self.raw_value:
 158                 if isinstance(self.field, models.DateTimeField):
 159                     objs = capfirst(formats.date_format(self.raw_value, 'DATETIME_FORMAT'))
 160                 elif isinstance(self.field, models.TimeField):
 161                     objs = capfirst(formats.time_format(self.raw_value, 'TIME_FORMAT'))
 162                 else:
 163                     objs = capfirst(formats.date_format(self.raw_value, 'DATE_FORMAT'))
 164             else:
 165                 objs = EMPTY_VALUE
 166         elif isinstance(self.field, models.BooleanField) or isinstance(self.field, models.NullBooleanField):
 167             objs = {True: 'Yes', False: 'No', None: 'Unknown'}[self.raw_value]
 168         else:
 169             objs = self.raw_value
 170         return [objs]
 171
 172     def urls(self):
 173         "Returns a list of (value, URL) tuples."
 174         # First, check the urls() method for each plugin.
 175         plugin_urls = []
 176         for plugin_name, plugin in self.model.model_databrowse().plugins.items():
 177             urls = plugin.urls(plugin_name, self)
 178             if urls is not None:
 179                 #plugin_urls.append(urls)
 180                 values = self.values()
 181                 return zip(self.values(), urls)
 182         if self.field.rel:
 183             m = EasyModel(self.model.site, self.field.rel.to)
 184             if self.field.rel.to in self.model.model_list:
 185                 lst = []
 186                 for value in self.values():
 187                     if value is None:
 188                         continue
 189                     url = mark_safe('%s%s/%s/objects/%s/' % (self.model.site.root_url, m.model._meta.app_label, m.model._meta.module_name, iri_to_uri(value._get_pk_val())))
 190                     lst.append((smart_unicode(value), url))
 191             else:
 192                 lst = [(value, None) for value in self.values()]
 193         elif self.field.choices:
 194             lst = []
 195             for value in self.values():
 196                 url = mark_safe('%s%s/%s/fields/%s/%s/' % (self.model.site.root_url, self.model.model._meta.app_label, self.model.model._meta.module_name, self.field.name, iri_to_uri(self.raw_value)))
 197                 lst.append((value, url))
 198         elif isinstance(self.field, models.URLField):
 199             val = self.values()[0]
 200             lst = [(val, iri_to_uri(val))]
 201         else:
 202             lst = [(self.values()[0], None)]
 203         return lst
 204
 205 class EasyQuerySet(QuerySet):
 206     """
 207     When creating (or cloning to) an `EasyQuerySet`, make sure to set the
 208     `_easymodel` variable to the related `EasyModel`.
 209     """
 210     def iterator(self, *args, **kwargs):
 211         for obj in super(EasyQuerySet, self).iterator(*args, **kwargs):
 212             yield EasyInstance(self._easymodel, obj)
 213
 214     def _clone(self, *args, **kwargs):
 215         c = super(EasyQuerySet, self)._clone(*args, **kwargs)
 216         c._easymodel = self._easymodel
 217         return c