Fixed #21323 -- Improved readability of serialized Operation. (374faa47) · Commits · Dom Sekotill / django

django/db/migrations/operations/base.py

+2 −0

Original line number	Diff line number	Diff line
		@@ -21,6 +21,8 @@ class Operation(object):
		# Can this migration be represented as SQL? (things like RunPython cannot)
		reduces_to_sql = True

		serialization_expand_args = []

		def __new__(cls, args, *kwargs):
		# We capture the arguments to make returning them trivial
		self = object.__new__(cls)

django/db/migrations/operations/models.py

+4 −2

Original line number	Diff line number	Diff line
		from .base import Operation
		from django.utils import six
		from django.db import models, router
		from django.db.models.options import normalize_unique_together
		from django.db.migrations.state import ModelState
		from django.db.migrations.operations.base import Operation
		from django.utils import six


		class CreateModel(Operation):
		@@ -10,6 +10,8 @@ class CreateModel(Operation):
		Create a model's table.
		"""

		serialization_expand_args = ['fields', 'options']

		def __init__(self, name, fields, options=None, bases=None):
		self.name = name
		self.fields = fields

django/db/migrations/writer.py

+88 −29

Original line number	Diff line number	Diff line
		from __future__ import unicode_literals

		import datetime
		import inspect
		from importlib import import_module
		import os
		import types
		@@ -27,6 +28,64 @@ class SettingsReference(str):
		self.setting_name = setting_name


		class OperationWriter(object):
		indentation = 2

		def __init__(self, operation):
		self.operation = operation
		self.buff = []

		def serialize(self):
		imports = set()
		name, args, kwargs = self.operation.deconstruct()
		argspec = inspect.getargspec(self.operation.__init__)
		normalized_kwargs = inspect.getcallargs(self.operation.__init__, args, *kwargs)

		self.feed('migrations.%s(' % name)
		self.indent()
		for arg_name in argspec.args[1:]:
		arg_value = normalized_kwargs[arg_name]
		if (arg_name in self.operation.serialization_expand_args and
		isinstance(arg_value, (list, tuple, dict))):
		if isinstance(arg_value, dict):
		self.feed('%s={' % arg_name)
		self.indent()
		for key, value in arg_value.items():
		arg_string, arg_imports = MigrationWriter.serialize(value)
		self.feed('%s: %s,' % (repr(key), arg_string))
		imports.update(arg_imports)
		self.unindent()
		self.feed('},')
		else:
		self.feed('%s=[' % arg_name)
		self.indent()
		for item in arg_value:
		arg_string, arg_imports = MigrationWriter.serialize(item)
		self.feed('%s,' % arg_string)
		imports.update(arg_imports)
		self.unindent()
		self.feed('],')
		else:
		arg_string, arg_imports = MigrationWriter.serialize(arg_value)
		self.feed('%s=%s,' % (arg_name, arg_string))
		imports.update(arg_imports)
		self.unindent()
		self.feed('),')
		return self.render(), imports

		def indent(self):
		self.indentation += 1

		def unindent(self):
		self.indentation -= 1

		def feed(self, line):
		self.buff.append(' ' * (self.indentation * 4) + line)

		def render(self):
		return '\n'.join(self.buff)


		class MigrationWriter(object):
		"""
		Takes a Migration instance and is able to produce the contents
		@@ -43,40 +102,35 @@ class MigrationWriter(object):
		items = {
		"replaces_str": "",
		}

		imports = set()

		# Deconstruct operations
		operation_strings = []
		operations = []
		for operation in self.migration.operations:
		name, args, kwargs = operation.deconstruct()
		arg_strings = []
		for arg in args:
		arg_string, arg_imports = self.serialize(arg)
		arg_strings.append(arg_string)
		imports.update(arg_imports)
		for kw, arg in kwargs.items():
		arg_string, arg_imports = self.serialize(arg)
		imports.update(arg_imports)
		arg_strings.append("%s = %s" % (kw, arg_string))
		operation_strings.append("migrations.%s(%s\n )" % (name, "".join("\n %s," % arg for arg in arg_strings)))
		items["operations"] = "[%s\n ]" % "".join("\n %s," % s for s in operation_strings)
		operation_string, operation_imports = OperationWriter(operation).serialize()
		imports.update(operation_imports)
		operations.append(operation_string)
		items["operations"] = "\n".join(operations) + "\n" if operations else ""

		# Format dependencies and write out swappable dependencies right
		items["dependencies"] = "["
		dependencies = []
		for dependency in self.migration.dependencies:
		if dependency[0] == "__setting__":
		items["dependencies"] += "\n migrations.swappable_dependency(settings.%s)," % dependency[1]
		dependencies.append(" migrations.swappable_dependency(settings.%s)," % dependency[1])
		imports.add("from django.conf import settings")
		else:
		items["dependencies"] += "\n %s," % repr(dependency)
		items["dependencies"] += "\n ]"
		dependencies.append(" %s," % repr(dependency))
		items["dependencies"] = "\n".join(dependencies) + "\n" if dependencies else ""

		# Format imports nicely
		imports.discard("from django.db import models")
		if not imports:
		items["imports"] = ""
		else:
		items["imports"] = "\n".join(imports) + "\n"
		items["imports"] = "\n".join(imports) + "\n" if imports else ""

		# If there's a replaces, make a string for it
		if self.migration.replaces:
		items['replaces_str'] = "\n replaces = %s\n" % repr(self.migration.replaces)

		return (MIGRATION_TEMPLATE % items).encode("utf8")

		@property
		@@ -110,16 +164,16 @@ class MigrationWriter(object):
		else:
		imports = set(["import %s" % module])
		name = path
		arg_strings = []
		strings = []
		for arg in args:
		arg_string, arg_imports = cls.serialize(arg)
		arg_strings.append(arg_string)
		strings.append(arg_string)
		imports.update(arg_imports)
		for kw, arg in kwargs.items():
		arg_string, arg_imports = cls.serialize(arg)
		imports.update(arg_imports)
		arg_strings.append("%s=%s" % (kw, arg_string))
		return "%s(%s)" % (name, ", ".join(arg_strings)), imports
		strings.append("%s=%s" % (kw, arg_string))
		return "%s(%s)" % (name, ", ".join(strings)), imports

		@classmethod
		def serialize(cls, value):
		@@ -140,7 +194,7 @@ class MigrationWriter(object):
		if isinstance(value, set):
		format = "set([%s])"
		elif isinstance(value, tuple):
		format = "(%s,)"
		format = "(%s)" if len(value) else "(%s,)"
		else:
		format = "[%s]"
		return format % (", ".join(strings)), imports
		@@ -204,13 +258,18 @@ class MigrationWriter(object):
		raise ValueError("Cannot serialize: %r" % value)


		MIGRATION_TEMPLATE = """# encoding: utf8
		MIGRATION_TEMPLATE = """\
		# encoding: utf8
		from django.db import models, migrations
		%(imports)s

		class Migration(migrations.Migration):
		%(replaces_str)s
		dependencies = %(dependencies)s
		dependencies = [
		%(dependencies)s\
		]

		operations = %(operations)s
		operations = [
		%(operations)s\
		]
		"""

tests/migrations/test_writer.py

+14 −1

Original line number	Diff line number	Diff line
		@@ -107,10 +107,23 @@ class WriterTests(TestCase):
		"""
		Tests serializing a simple migration.
		"""
		fields = {
		'charfield': models.DateTimeField(default=datetime.datetime.utcnow),
		'datetimefield': models.DateTimeField(default=datetime.datetime.utcnow),
		}

		options = {
		'verbose_name': 'My model',
		'verbose_name_plural': 'My models',
		}

		migration = type(str("Migration"), (migrations.Migration,), {
		"operations": [
		migrations.CreateModel("MyModel", tuple(fields.items()), options, (models.Model,)),
		migrations.CreateModel("MyModel2", tuple(fields.items()), bases=(models.Model,)),
		migrations.CreateModel(name="MyModel3", fields=tuple(fields.items()), options=options, bases=(models.Model,)),
		migrations.DeleteModel("MyModel"),
		migrations.AddField("OtherModel", "field_name", models.DateTimeField(default=datetime.datetime.utcnow))
		migrations.AddField("OtherModel", "datetimefield", fields["datetimefield"]),
		],
		"dependencies": [("testapp", "some_other_one")],
		})