Django

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Ticket #6095: 6095-alpha-01.diff

File 6095-alpha-01.diff, 9.6 kB (added by floguy, 1 year ago)

Rudimentary patch to get the base functionality working. Tests were first, then implementation.

  • django/db/models/fields/related.py

    old new  
    11from django.db import connection, transaction 
    2 from django.db.models import signals, get_model 
     2from django.db.models import signals, get_model, get_models 
    33from django.db.models.fields import AutoField, Field, IntegerField, PositiveIntegerField, PositiveSmallIntegerField, get_ul_class 
    44from django.db.models.related import RelatedObject 
    55from django.utils.text import capfirst 
    66from django.utils.translation import ugettext_lazy, string_concat, ungettext, ugettext as _ 
    7 from django.utils.functional import curry 
     7from django.utils.functional import curry, memoize 
    88from django.utils.encoding import smart_unicode 
    99from django.core import validators 
    1010from django import oldforms 
     
    2323 
    2424pending_lookups = {} 
    2525 
     26memoized_fk_field_reversals = {} 
     27 
     28model_db_table_cache = {} 
     29 
    2630def add_lookup(rel_cls, field): 
    2731    name = field.rel.to 
    2832    module = rel_cls.__module__ 
     
    5458    except klass.DoesNotExist: 
    5559        raise validators.ValidationError, _("Please enter a valid %s.") % f.verbose_name 
    5660 
     61def get_reverse_rel_field(from_model, to_model, related_name): 
     62    key = (from_model._meta.app_label, from_model._meta.object_name, 
     63            to_model._meta.app_label, to_model._meta.object_name, 
     64            related_name) 
     65    try: 
     66        found_field = memoized_fk_field_reversals[key] 
     67    except KeyError: 
     68        found_field = None 
     69        for field in from_model._meta.fields: 
     70            if field.__class__ in (ForeignKey, OneToOneField, ManyToManyField): 
     71                if field.rel.related_name == related_name: 
     72                    if field.rel.to == to_model: 
     73                        found_field = field 
     74                        break 
     75        memoized_fk_field_reversals[key] = found_field 
     76    return found_field 
     77 
     78def get_model_for_db_table(db_table): 
     79    for model in get_models(): 
     80        if model._meta.db_table == db_table: 
     81            return model 
     82    return None 
     83get_model_for_db_table = memoize(get_model_for_db_table, model_db_table_cache, 1) 
     84 
    5785#HACK 
    5886class RelatedField(object): 
    5987    def contribute_to_class(self, cls, name): 
     
    276304            self.join_table = join_table 
    277305            self.source_col_name = source_col_name 
    278306            self.target_col_name = target_col_name 
     307            self.intermediary_model = get_model_for_db_table(self.join_table.replace('"','')) 
    279308            self._pk_val = self.instance._get_pk_val() 
    280309            if self._pk_val is None: 
    281310                raise ValueError("%r instance needs to have a primary key value before a many-to-many relationship can be used." % model) 
     
    340369 
    341370                # Add the ones that aren't there already 
    342371                for obj_id in (new_ids - existing_ids): 
    343                     cursor.execute("INSERT INTO %s (%s, %s) VALUES (%%s, %%s)" % \ 
     372                    if self.intermediary_model == None: 
     373                        cursor.execute("INSERT INTO %s (%s, %s) VALUES (%%s, %%s)" % \ 
    344374                        (self.join_table, source_col_name, target_col_name), 
    345375                        [self._pk_val, obj_id]) 
     376                    else: 
     377                        new_obj = self.intermediary_model() 
     378                        setattr(new_obj, source_col_name.replace('"', ''), self._pk_val) 
     379                        setattr(new_obj, target_col_name.replace('"', ''), obj_id) 
     380                        new_obj.save() 
    346381                transaction.commit_unless_managed() 
    347382 
    348383        def _remove_items(self, source_col_name, target_col_name, *objs): 
     
    648683            filter_interface=kwargs.pop('filter_interface', None), 
    649684            limit_choices_to=kwargs.pop('limit_choices_to', None), 
    650685            raw_id_admin=kwargs.pop('raw_id_admin', False), 
    651             symmetrical=kwargs.pop('symmetrical', True)) 
     686            symmetrical=kwargs.pop('symmetrical', True), 
     687            through=kwargs.pop('through', None)) 
    652688        self.db_table = kwargs.pop('db_table', None) 
    653689        if kwargs["rel"].raw_id_admin: 
    654690            kwargs.setdefault("validator_list", []).append(self.isValidIDList) 
     
    672708 
    673709    def _get_m2m_db_table(self, opts): 
    674710        "Function that can be curried to provide the m2m table name for this relation" 
    675         if self.db_table: 
     711        if self.rel.through != None: 
     712            return get_model(opts.app_label, self.rel.through)._meta.db_table 
     713        elif self.db_table: 
    676714            return self.db_table 
    677715        else: 
    678716            return '%s_%s' % (opts.db_table, self.name) 
     
    680718    def _get_m2m_column_name(self, related): 
    681719        "Function that can be curried to provide the source column name for the m2m table" 
    682720        # If this is an m2m relation to self, avoid the inevitable name clash 
    683         if related.model == related.parent_model: 
     721        if self.rel.through != None: 
     722            through = get_model(related.opts.app_label, self.rel.through) 
     723            field = get_reverse_rel_field(through, related.model, self.rel.related_name) 
     724            attname, column = field.get_attname_column() 
     725            return column 
     726        elif related.model == related.parent_model: 
    684727            return 'from_' + related.model._meta.object_name.lower() + '_id' 
    685728        else: 
    686729            return related.model._meta.object_name.lower() + '_id' 
     
    688731    def _get_m2m_reverse_name(self, related): 
    689732        "Function that can be curried to provide the related column name for the m2m table" 
    690733        # If this is an m2m relation to self, avoid the inevitable name clash 
    691         if related.model == related.parent_model: 
     734        if self.rel.through != None: 
     735            through = get_model(related.opts.app_label, self.rel.through) 
     736            field = get_reverse_rel_field(through, related.parent_model, self.rel.related_name) 
     737            attname, column = field.get_attname_column() 
     738            return column 
     739        elif related.model == related.parent_model: 
    692740            return 'to_' + related.parent_model._meta.object_name.lower() + '_id' 
    693741        else: 
    694742            return related.parent_model._meta.object_name.lower() + '_id' 
     
    809857 
    810858class ManyToManyRel(object): 
    811859    def __init__(self, to, num_in_admin=0, related_name=None, 
    812         filter_interface=None, limit_choices_to=None, raw_id_admin=False, symmetrical=True): 
     860        filter_interface=None, limit_choices_to=None, raw_id_admin=False, symmetrical=True, 
     861        through = None): 
    813862        self.to = to 
    814863        self.num_in_admin = num_in_admin 
    815864        self.related_name = related_name 
     
    821870        self.raw_id_admin = raw_id_admin 
    822871        self.symmetrical = symmetrical 
    823872        self.multiple = True 
     873        self.through = through 
    824874 
    825875        assert not (self.raw_id_admin and self.filter_interface), "ManyToManyRels may not use both raw_id_admin and filter_interface" 
  • django/core/management/sql.py

    old new  
    349349    qn = connection.ops.quote_name 
    350350    inline_references = connection.features.inline_fk_references 
    351351    for f in opts.many_to_many: 
    352         if not isinstance(f.rel, generic.GenericRel)
     352        if not isinstance(f.rel, generic.GenericRel) and getattr(f.rel, 'through', None) == None
    353353            tablespace = f.db_tablespace or opts.db_tablespace 
    354354            if tablespace and connection.features.supports_tablespaces and connection.features.autoindexes_primary_keys: 
    355355                tablespace_sql = ' ' + connection.ops.tablespace_sql(tablespace, inline=True) 
  • tests/modeltests/m2m_manual/models.py

    old new  
     1from django.db import models 
     2from datetime import datetime 
     3 
     4# M2M described on one of the models 
     5class Person(models.Model): 
     6    name = models.CharField(max_length=128) 
     7 
     8    def __unicode__(self): 
     9        return self.name 
     10 
     11class Group(models.Model): 
     12    name = models.CharField(max_length=128) 
     13    members = models.ManyToManyField(Person, through='Membership') 
     14     
     15    def __unicode__(self): 
     16        return self.name 
     17 
     18class Membership(models.Model): 
     19    person = models.ForeignKey(Person) 
     20    group = models.ForeignKey(Group) 
     21    date_joined = models.DateTimeField(default=datetime.now) 
     22     
     23    def __unicode__(self): 
     24        return "%s is a member of %s" % (self.person.name, self.group.name) 
     25 
     26__test__ = {'API_TESTS':""" 
     27>>> bob = Person(name = 'Bob') 
     28>>> bob.save() 
     29>>> jim = Person(name = 'Jim') 
     30>>> jim.save() 
     31>>> jane = Person(name = 'Jane') 
     32>>> jane.save() 
     33>>> rock = Group(name = 'Rock') 
     34>>> rock.save() 
     35>>> roll = Group(name = 'Roll') 
     36>>> roll.save() 
     37 
     38>>> rock.members.add(jim, jane) 
     39>>> rock.members.all() 
     40[<Person: Jim>, <Person: Jane>] 
     41 
     42>>> roll.members.add(bob, jim) 
     43>>> roll.members.all() 
     44[<Person: Bob>, <Person: Jim>] 
     45 
     46>>> jane.group_set.all() 
     47[<Group: Rock>] 
     48 
     49>>> jane.group_set.add(roll) 
     50>>> jane.group_set.all() 
     51[<Group: Rock>, <Group: Roll>] 
     52 
     53>>> jim.group_set.all() 
     54[<Group: Rock>, <Group: Roll>] 
     55 
     56>>> Membership.objects.filter(person = jane, group = rock) 
     57[<Membership: Jane is a member of Rock>] 
     58 
     59>>> Membership.objects.filter(person = jim) 
     60[<Membership: Jim is a member of Rock>, <Membership: Jim is a member of Roll>] 
     61"""}