68 lines
3.0 KiB
Python
68 lines
3.0 KiB
Python
from collections import namedtuple
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from django.utils.encoding import smart_text
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from django.db.models.fields import BLANK_CHOICE_DASH
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# PathInfo is used when converting lookups (fk__somecol). The contents
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# describe the relation in Model terms (model Options and Fields for both
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# sides of the relation. The join_field is the field backing the relation.
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PathInfo = namedtuple('PathInfo',
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'from_field to_field from_opts to_opts join_field '
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'm2m direct')
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class RelatedObject(object):
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def __init__(self, parent_model, model, field):
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self.parent_model = parent_model
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self.model = model
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self.opts = model._meta
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self.field = field
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self.name = '%s:%s' % (self.opts.app_label, self.opts.model_name)
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self.var_name = self.opts.model_name
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def get_choices(self, include_blank=True, blank_choice=BLANK_CHOICE_DASH,
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limit_to_currently_related=False):
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"""Returns choices with a default blank choices included, for use
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as SelectField choices for this field.
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Analogue of django.db.models.fields.Field.get_choices, provided
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initially for utilisation by RelatedFieldListFilter.
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"""
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first_choice = include_blank and blank_choice or []
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queryset = self.model._default_manager.all()
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if limit_to_currently_related:
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queryset = queryset.complex_filter(
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{'%s__isnull' % self.parent_model._meta.model_name: False})
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lst = [(x._get_pk_val(), smart_text(x)) for x in queryset]
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return first_choice + lst
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def get_db_prep_lookup(self, lookup_type, value, connection, prepared=False):
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# Defer to the actual field definition for db prep
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return self.field.get_db_prep_lookup(lookup_type, value,
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connection=connection, prepared=prepared)
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def editable_fields(self):
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"Get the fields in this class that should be edited inline."
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return [f for f in self.opts.fields + self.opts.many_to_many if f.editable and f != self.field]
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def __repr__(self):
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return "<RelatedObject: %s related to %s>" % (self.name, self.field.name)
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def get_accessor_name(self):
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# This method encapsulates the logic that decides what name to give an
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# accessor descriptor that retrieves related many-to-one or
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# many-to-many objects. It uses the lower-cased object_name + "_set",
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# but this can be overridden with the "related_name" option.
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if self.field.rel.multiple:
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# If this is a symmetrical m2m relation on self, there is no reverse accessor.
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if getattr(self.field.rel, 'symmetrical', False) and self.model == self.parent_model:
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return None
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return self.field.rel.related_name or (self.opts.model_name + '_set')
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else:
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return self.field.rel.related_name or (self.opts.model_name)
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def get_cache_name(self):
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return "_%s_cache" % self.get_accessor_name()
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def get_path_info(self):
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return self.field.get_reverse_path_info()
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