def generate_added_fields(self):
# New fields
self.renamed_fields = {}
for app_label, model_name, field_name in sorted(self.new_field_keys - self.old_field_keys):
old_model_name = self.renamed_models.get((app_label, model_name), model_name)
old_model_state = self.from_state.models[app_label, old_model_name]
new_model_state = self.to_state.models[app_label, model_name]
field = new_model_state.get_field_by_name(field_name)
# Scan to see if this is actually a rename!
field_dec = self.deep_deconstruct(field)
found_rename = False
for rem_app_label, rem_model_name, rem_field_name in sorted(self.old_field_keys - self.new_field_keys):
if rem_app_label == app_label and rem_model_name == model_name:
old_field_dec = self.deep_deconstruct(old_model_state.get_field_by_name(rem_field_name))
if field.rel and field.rel.to and 'to' in old_field_dec[2]:
old_rel_to = old_field_dec[2]['to']
if old_rel_to in self.renamed_models_rel:
old_field_dec[2]['to'] = self.renamed_models_rel[old_rel_to]
if old_field_dec == field_dec:
if self.questioner.ask_rename(model_name, rem_field_name, field_name, field):
self.add_operation(
app_label,
operations.RenameField(
model_name=model_name,
old_name=rem_field_name,
new_name=field_name,
)
)
self.old_field_keys.remove((rem_app_label, rem_model_name, rem_field_name))
self.old_field_keys.add((app_label, model_name, field_name))
self.renamed_fields[app_label, model_name, field_name] = rem_field_name
found_rename = True
break
if found_rename:
continue
# You can't just add NOT NULL fields with no default
if not field.null and not field.has_default() and not isinstance(field, models.ManyToManyField):
field = field.clone()
field.default = self.questioner.ask_not_null_addition(field_name, model_name)
self.add_operation(
app_label,
operations.AddField(
model_name=model_name,
name=field_name,
field=field,
preserve_default=False,
)
)
else:
self.add_operation(
app_label,
operations.AddField(
model_name=model_name,
name=field_name,
field=field,
)
)
def test_operation_is_safe(self):
assert migration_utils.operation_is_safe(
operations.AddField(
model_name="unsafemodel",
name="safe_field",
field=models.IntegerField(null=True),
)
)
assert (
migration_utils.operation_is_safe(
operations.AddField(
model_name="unsafemodel",
name="field_added",
field=models.IntegerField(default=1),
preserve_default=False,
)
)
is False
)
assert (
migration_utils.operation_is_safe(
operations.AlterField(
model_name="unsafemodel",
name="field_added",
field=models.PositiveIntegerField(default=10),
preserve_default=False,
)
)
is False
)
assert (
migration_utils.operation_is_safe(
operations.RenameField(
model_name="unsafemodel", old_name="field_added", new_name="field_renamed"
)
)
is False
)
assert (
migration_utils.operation_is_safe(
operations.RemoveField(
model_name="unsafemodel",
name="field_renamed",
)
)
is False
)
assert migration_utils.operation_is_safe(operations.DeleteModel("unsafemodel")) is False
assert migration_utils.operation_is_safe(operations.RunSQL("")) is False
assert migration_utils.operation_is_safe(operations.RunPython(lambda: True)) is False
def _detect_changes(self):
"""
Returns a dict of migration plans which will achieve the
change from from_state to to_state. The dict has app labels
as keys and a list of migrations as values.
The resulting migrations aren't specially named, but the names
do matter for dependencies inside the set.
"""
# We'll store migrations as lists by app names for now
self.migrations = {}
old_app_cache = self.from_state.render()
new_app_cache = self.to_state.render()
# Prepare lists of old/new model keys that we care about
# (i.e. ignoring proxy ones)
old_model_keys = [
(al, mn)
for al, mn in self.from_state.models.keys()
if not old_app_cache.get_model(al, mn)._meta.proxy
]
new_model_keys = [
(al, mn)
for al, mn in self.to_state.models.keys()
if not new_app_cache.get_model(al, mn)._meta.proxy
]
# Adding models. Phase 1 is adding models with no outward relationships.
added_models = set(new_model_keys) - set(old_model_keys)
pending_add = {}
for app_label, model_name in added_models:
model_state = self.to_state.models[app_label, model_name]
# Are there any relationships out from this model? if so, punt it to the next phase.
related_fields = []
for field in new_app_cache.get_model(app_label, model_name)._meta.local_fields:
if field.rel:
if field.rel.to:
related_fields.append((field.name, field.rel.to._meta.app_label.lower(), field.rel.to._meta.object_name.lower()))
if hasattr(field.rel, "through") and not field.rel.though._meta.auto_created:
related_fields.append((field.name, field.rel.through._meta.app_label.lower(), field.rel.through._meta.object_name.lower()))
if related_fields:
pending_add[app_label, model_name] = related_fields
else:
self.add_to_migration(
app_label,
operations.CreateModel(
name=model_state.name,
fields=model_state.fields,
options=model_state.options,
bases=model_state.bases,
)
)
# Phase 2 is progressively adding pending models, splitting up into two
# migrations if required.
pending_new_fks = []
while pending_add:
# Is there one we can add that has all dependencies satisfied?
satisfied = [(m, rf) for m, rf in pending_add.items() if all((al, mn) not in pending_add for f, al, mn in rf)]
if satisfied:
(app_label, model_name), related_fields = sorted(satisfied)[0]
model_state = self.to_state.models[app_label, model_name]
self.add_to_migration(
app_label,
operations.CreateModel(
name=model_state.name,
fields=model_state.fields,
options=model_state.options,
bases=model_state.bases,
)
)
for field_name, other_app_label, other_model_name in related_fields:
if app_label != other_app_label:
self.add_dependency(app_label, other_app_label)
del pending_add[app_label, model_name]
# Ah well, we'll need to split one. Pick deterministically.
else:
(app_label, model_name), related_fields = sorted(pending_add.items())[0]
model_state = self.to_state.models[app_label, model_name]
# Work out the fields that need splitting out
bad_fields = dict((f, (al, mn)) for f, al, mn in related_fields if (al, mn) in pending_add)
# Create the model, without those
self.add_to_migration(
app_label,
operations.CreateModel(
name=model_state.name,
fields=[(n, f) for n, f in model_state.fields if n not in bad_fields],
options=model_state.options,
bases=model_state.bases,
)
)
# Add the bad fields to be made in a phase 3
for field_name, (other_app_label, other_model_name) in bad_fields.items():
pending_new_fks.append((app_label, model_name, field_name, other_app_label))
del pending_add[app_label, model_name]
# Phase 3 is adding the final set of FKs as separate new migrations
for app_label, model_name, field_name, other_app_label in pending_new_fks:
model_state = self.to_state.models[app_label, model_name]
self.add_to_migration(
app_label,
operations.AddField(
model_name=model_name,
name=field_name,
field=model_state.get_field_by_name(field_name),
),
new=True,
)
if app_label != other_app_label:
self.add_dependency(app_label, other_app_label)
# Removing models
removed_models = set(old_model_keys) - set(new_model_keys)
for app_label, model_name in removed_models:
model_state = self.from_state.models[app_label, model_name]
self.add_to_migration(
app_label,
operations.DeleteModel(
model_state.name,
)
)
# Changes within models
kept_models = set(old_model_keys).intersection(new_model_keys)
old_fields = set()
new_fields = set()
for app_label, model_name in kept_models:
old_model_state = self.from_state.models[app_label, model_name]
new_model_state = self.to_state.models[app_label, model_name]
# Collect field changes for later global dealing with (so AddFields
# always come before AlterFields even on separate models)
old_fields.update((app_label, model_name, x) for x, y in old_model_state.fields)
new_fields.update((app_label, model_name, x) for x, y in new_model_state.fields)
# Unique_together changes
if old_model_state.options.get("unique_together", set()) != new_model_state.options.get("unique_together", set()):
self.add_to_migration(
app_label,
operations.AlterUniqueTogether(
name=model_name,
unique_together=new_model_state.options.get("unique_together", set()),
)
)
# New fields
for app_label, model_name, field_name in new_fields - old_fields:
old_model_state = self.from_state.models[app_label, model_name]
new_model_state = self.to_state.models[app_label, model_name]
field = new_model_state.get_field_by_name(field_name)
# Scan to see if this is actually a rename!
field_dec = field.deconstruct()[1:]
found_rename = False
for rem_app_label, rem_model_name, rem_field_name in (old_fields - new_fields):
if rem_app_label == app_label and rem_model_name == model_name:
if old_model_state.get_field_by_name(rem_field_name).deconstruct()[1:] == field_dec:
if self.questioner.ask_rename(model_name, rem_field_name, field_name, field):
self.add_to_migration(
app_label,
operations.RenameField(
model_name=model_name,
old_name=rem_field_name,
new_name=field_name,
)
)
old_fields.remove((rem_app_label, rem_model_name, rem_field_name))
new_fields.remove((app_label, model_name, field_name))
found_rename = True
break
if found_rename:
continue
# You can't just add NOT NULL fields with no default
if not field.null and not field.has_default():
field = field.clone()
field.default = self.questioner.ask_not_null_addition(field_name, model_name)
self.add_to_migration(
app_label,
operations.AddField(
model_name=model_name,
name=field_name,
field=field,
preserve_default=False,
)
)
else:
self.add_to_migration(
app_label,
operations.AddField(
model_name=model_name,
name=field_name,
field=field,
)
)
# Old fields
for app_label, model_name, field_name in old_fields - new_fields:
old_model_state = self.from_state.models[app_label, model_name]
new_model_state = self.to_state.models[app_label, model_name]
self.add_to_migration(
app_label,
operations.RemoveField(
model_name=model_name,
name=field_name,
)
)
# The same fields
for app_label, model_name, field_name in old_fields.intersection(new_fields):
# Did the field change?
old_model_state = self.from_state.models[app_label, model_name]
new_model_state = self.to_state.models[app_label, model_name]
old_field_dec = old_model_state.get_field_by_name(field_name).deconstruct()
new_field_dec = new_model_state.get_field_by_name(field_name).deconstruct()
if old_field_dec != new_field_dec:
self.add_to_migration(
app_label,
operations.AlterField(
model_name=model_name,
name=field_name,
field=new_model_state.get_field_by_name(field_name),
)
)
# Alright, now add internal dependencies
for app_label, migrations in self.migrations.items():
for m1, m2 in zip(migrations, migrations[1:]):
m2.dependencies.append((app_label, m1.name))
# Clean up dependencies
for app_label, migrations in self.migrations.items():
for migration in migrations:
migration.dependencies = list(set(migration.dependencies))
return self.migrations
def _detect_changes(self):
"""
Returns a dict of migration plans which will achieve the
change from from_state to to_state. The dict has app labels
as keys and a list of migrations as values.
The resulting migrations aren't specially named, but the names
do matter for dependencies inside the set.
"""
# We'll store migrations as lists by app names for now
self.migrations = {}
old_apps = self.from_state.render()
new_apps = self.to_state.render()
# Prepare lists of old/new model keys that we care about
# (i.e. ignoring proxy ones)
old_model_keys = [(al, mn) for al, mn in self.from_state.models.keys()
if not old_apps.get_model(al, mn)._meta.proxy]
new_model_keys = [(al, mn) for al, mn in self.to_state.models.keys()
if not new_apps.get_model(al, mn)._meta.proxy]
def _rel_agnostic_fields_def(fields):
"""
Return a definition of the fields that ignores field names and
what related fields actually relate to.
"""
fields_def = []
for name, field in fields:
deconstruction = field.deconstruct()[1:]
if field.rel and field.rel.to:
del deconstruction[2]['to']
fields_def.append(deconstruction)
return fields_def
# Find any renamed models.
renamed_models = {}
renamed_models_rel = {}
added_models = set(new_model_keys) - set(old_model_keys)
for app_label, model_name in added_models:
model_state = self.to_state.models[app_label, model_name]
model_fields_def = _rel_agnostic_fields_def(model_state.fields)
removed_models = set(old_model_keys) - set(new_model_keys)
for rem_app_label, rem_model_name in removed_models:
if rem_app_label == app_label:
rem_model_state = self.from_state.models[rem_app_label,
rem_model_name]
rem_model_fields_def = _rel_agnostic_fields_def(
rem_model_state.fields)
if model_fields_def == rem_model_fields_def:
if self.questioner.ask_rename_model(
rem_model_state, model_state):
self.add_to_migration(
app_label,
operations.RenameModel(
old_name=rem_model_state.name,
new_name=model_state.name,
))
renamed_models[app_label,
model_name] = rem_model_name
renamed_models_rel[
'%s.%s' %
(rem_model_state.app_label,
rem_model_state.name)] = '%s.%s' % (
model_state.app_label, model_state.name)
old_model_keys.remove(
(rem_app_label, rem_model_name))
old_model_keys.append((app_label, model_name))
break
# Adding models. Phase 1 is adding models with no outward relationships.
added_models = set(new_model_keys) - set(old_model_keys)
pending_add = {}
for app_label, model_name in added_models:
model_state = self.to_state.models[app_label, model_name]
# Are there any relationships out from this model? if so, punt it to the next phase.
related_fields = []
for field in new_apps.get_model(app_label,
model_name)._meta.local_fields:
if field.rel:
if field.rel.to:
related_fields.append(
(field.name, field.rel.to._meta.app_label,
field.rel.to._meta.model_name))
if hasattr(field.rel, "through"
) and not field.rel.through._meta.auto_created:
related_fields.append(
(field.name, field.rel.through._meta.app_label,
field.rel.through._meta.model_name))
for field in new_apps.get_model(
app_label, model_name)._meta.local_many_to_many:
if field.rel.to:
related_fields.append(
(field.name, field.rel.to._meta.app_label,
field.rel.to._meta.model_name))
if hasattr(field.rel, "through"
) and not field.rel.through._meta.auto_created:
related_fields.append(
(field.name, field.rel.through._meta.app_label,
field.rel.through._meta.model_name))
if related_fields:
pending_add[app_label, model_name] = related_fields
else:
self.add_to_migration(
app_label,
operations.CreateModel(
name=model_state.name,
fields=model_state.fields,
options=model_state.options,
bases=model_state.bases,
))
# Phase 2 is progressively adding pending models, splitting up into two
# migrations if required.
pending_new_fks = []
pending_unique_together = []
added_phase_2 = set()
while pending_add:
# Is there one we can add that has all dependencies satisfied?
satisfied = [(m, rf) for m, rf in pending_add.items() if all(
(al, mn) not in pending_add for f, al, mn in rf)]
if satisfied:
(app_label, model_name), related_fields = sorted(satisfied)[0]
model_state = self.to_state.models[app_label, model_name]
self.add_to_migration(
app_label,
operations.CreateModel(
name=model_state.name,
fields=model_state.fields,
options=model_state.options,
bases=model_state.bases,
),
# If it's already been added in phase 2 put it in a new
# migration for safety.
new=any((al, mn) in added_phase_2
for f, al, mn in related_fields),
)
for field_name, other_app_label, other_model_name in related_fields:
# If it depends on a swappable something, add a dynamic depend'cy
swappable_setting = new_apps.get_model(
app_label, model_name)._meta.get_field_by_name(
field_name)[0].swappable_setting
if swappable_setting is not None:
self.add_swappable_dependency(app_label,
swappable_setting)
elif app_label != other_app_label:
self.add_dependency(app_label, other_app_label)
del pending_add[app_label, model_name]
added_phase_2.add((app_label, model_name))
# Ah well, we'll need to split one. Pick deterministically.
else:
(app_label,
model_name), related_fields = sorted(pending_add.items())[0]
model_state = self.to_state.models[app_label, model_name]
# Defer unique together constraints creation, see ticket #22275
unique_together_constraints = model_state.options.pop(
'unique_together', None)
if unique_together_constraints:
pending_unique_together.append(
(app_label, model_name, unique_together_constraints))
# Work out the fields that need splitting out
bad_fields = dict((f, (al, mn)) for f, al, mn in related_fields
if (al, mn) in pending_add)
# Create the model, without those
self.add_to_migration(
app_label,
operations.CreateModel(
name=model_state.name,
fields=[(n, f) for n, f in model_state.fields
if n not in bad_fields],
options=model_state.options,
bases=model_state.bases,
))
# Add the bad fields to be made in a phase 3
for field_name, (other_app_label,
other_model_name) in bad_fields.items():
pending_new_fks.append(
(app_label, model_name, field_name, other_app_label))
del pending_add[app_label, model_name]
# Phase 3 is adding the final set of FKs as separate new migrations
for app_label, model_name, field_name, other_app_label in pending_new_fks:
model_state = self.to_state.models[app_label, model_name]
self.add_to_migration(
app_label,
operations.AddField(
model_name=model_name,
name=field_name,
field=model_state.get_field_by_name(field_name),
),
new=True,
)
# If it depends on a swappable something, add a dynamic depend'cy
swappable_setting = new_apps.get_model(
app_label, model_name)._meta.get_field_by_name(
field_name)[0].swappable_setting
if swappable_setting is not None:
self.add_swappable_dependency(app_label, swappable_setting)
elif app_label != other_app_label:
self.add_dependency(app_label, other_app_label)
# Phase 3.1 - unique together constraints
for app_label, model_name, unique_together in pending_unique_together:
self.add_to_migration(
app_label,
operations.AlterUniqueTogether(
name=model_name, unique_together=unique_together))
# Removing models
removed_models = set(old_model_keys) - set(new_model_keys)
for app_label, model_name in removed_models:
model_state = self.from_state.models[app_label, model_name]
self.add_to_migration(app_label,
operations.DeleteModel(model_state.name, ))
# Changes within models
kept_models = set(old_model_keys).intersection(new_model_keys)
old_fields = set()
new_fields = set()
unique_together_operations = []
for app_label, model_name in kept_models:
old_model_name = renamed_models.get((app_label, model_name),
model_name)
old_model_state = self.from_state.models[app_label, old_model_name]
new_model_state = self.to_state.models[app_label, model_name]
# Collect field changes for later global dealing with (so AddFields
# always come before AlterFields even on separate models)
old_fields.update(
(app_label, model_name, x) for x, y in old_model_state.fields)
new_fields.update(
(app_label, model_name, x) for x, y in new_model_state.fields)
# Unique_together changes. Operations will be added to migration a
# bit later, after fields creation. See ticket #22035.
if old_model_state.options.get(
"unique_together", set()) != new_model_state.options.get(
"unique_together", set()):
unique_together_operations.append(
(app_label,
operations.AlterUniqueTogether(
name=model_name,
unique_together=new_model_state.options.get(
"unique_together", set()),
)))
# New fields
renamed_fields = {}
for app_label, model_name, field_name in new_fields - old_fields:
old_model_name = renamed_models.get((app_label, model_name),
model_name)
old_model_state = self.from_state.models[app_label, old_model_name]
new_model_state = self.to_state.models[app_label, model_name]
field = new_model_state.get_field_by_name(field_name)
# Scan to see if this is actually a rename!
field_dec = field.deconstruct()[1:]
found_rename = False
for rem_app_label, rem_model_name, rem_field_name in (old_fields -
new_fields):
if rem_app_label == app_label and rem_model_name == model_name:
old_field_dec = old_model_state.get_field_by_name(
rem_field_name).deconstruct()[1:]
if field.rel and field.rel.to:
old_rel_to = old_field_dec[2]['to']
if old_rel_to in renamed_models_rel:
old_field_dec[2]['to'] = renamed_models_rel[
old_rel_to]
if old_field_dec == field_dec:
if self.questioner.ask_rename(model_name,
rem_field_name,
field_name, field):
self.add_to_migration(
app_label,
operations.RenameField(
model_name=model_name,
old_name=rem_field_name,
new_name=field_name,
))
old_fields.remove((rem_app_label, rem_model_name,
rem_field_name))
old_fields.add((app_label, model_name, field_name))
renamed_fields[app_label, model_name,
field_name] = rem_field_name
found_rename = True
break
if found_rename:
continue
# You can't just add NOT NULL fields with no default
if not field.null and not field.has_default():
field = field.clone()
field.default = self.questioner.ask_not_null_addition(
field_name, model_name)
self.add_to_migration(
app_label,
operations.AddField(
model_name=model_name,
name=field_name,
field=field,
preserve_default=False,
))
else:
self.add_to_migration(
app_label,
operations.AddField(
model_name=model_name,
name=field_name,
field=field,
))
new_field = new_apps.get_model(
app_label,
model_name)._meta.get_field_by_name(field_name)[0]
swappable_setting = getattr(new_field, 'swappable_setting',
None)
if swappable_setting is not None:
self.add_swappable_dependency(app_label, swappable_setting)
# Old fields
for app_label, model_name, field_name in old_fields - new_fields:
old_model_name = renamed_models.get((app_label, model_name),
model_name)
old_model_state = self.from_state.models[app_label, old_model_name]
new_model_state = self.to_state.models[app_label, model_name]
self.add_to_migration(
app_label,
operations.RemoveField(
model_name=model_name,
name=field_name,
))
# The same fields
for app_label, model_name, field_name in old_fields.intersection(
new_fields):
# Did the field change?
old_model_name = renamed_models.get((app_label, model_name),
model_name)
old_model_state = self.from_state.models[app_label, old_model_name]
new_model_state = self.to_state.models[app_label, model_name]
old_field_name = renamed_fields.get(
(app_label, model_name, field_name), field_name)
old_field_dec = old_model_state.get_field_by_name(
old_field_name).deconstruct()[1:]
new_field_dec = new_model_state.get_field_by_name(
field_name).deconstruct()[1:]
if old_field_dec != new_field_dec:
self.add_to_migration(
app_label,
operations.AlterField(
model_name=model_name,
name=field_name,
field=new_model_state.get_field_by_name(field_name),
))
for app_label, operation in unique_together_operations:
self.add_to_migration(app_label, operation)
# Alright, now add internal dependencies
for app_label, migrations in self.migrations.items():
for m1, m2 in zip(migrations, migrations[1:]):
m2.dependencies.append((app_label, m1.name))
# Clean up dependencies
for app_label, migrations in self.migrations.items():
for migration in migrations:
migration.dependencies = list(set(migration.dependencies))
return self.migrations
