mptt.managers: 373 total statements, 0.0% covered

Generated: Wed 2013-03-13 10:33 CET

Source file: /media/Envs/Envs/filer-gallery/lib/python2.7/site-packages/mptt/managers.py

Stats: 0 executed, 367 missed, 6 excluded, 501 ignored

  1. """
  2. A custom manager for working with trees of objects.
  3. """
  4. from django.db import connection, models, transaction
  5. from django.db.models import F, Max
  6. from django.utils.translation import ugettext as _
  7. try:
  8. from django.db import connections, router
  9. except ImportError:
  10. # multi db support was new in django 1.2
  11. # NOTE we don't support django 1.1 anymore, so this stuff is likely to get removed soon
  12. connections = None
  13. router = None
  14. from mptt.exceptions import InvalidMove
  15. from mptt.utils import _exists
  16. __all__ = ('TreeManager',)
  17. qn = connection.ops.quote_name
  18. COUNT_SUBQUERY = """(
  19. SELECT COUNT(*)
  20. FROM %(rel_table)s
  21. WHERE %(mptt_fk)s = %(mptt_table)s.%(mptt_pk)s
  22. )"""
  23. CUMULATIVE_COUNT_SUBQUERY = """(
  24. SELECT COUNT(*)
  25. FROM %(rel_table)s
  26. WHERE %(mptt_fk)s IN
  27. (
  28. SELECT m2.%(mptt_pk)s
  29. FROM %(mptt_table)s m2
  30. WHERE m2.%(tree_id)s = %(mptt_table)s.%(tree_id)s
  31. AND m2.%(left)s BETWEEN %(mptt_table)s.%(left)s
  32. AND %(mptt_table)s.%(right)s
  33. )
  34. )"""
  35. class TreeManager(models.Manager):
  36. """
  37. A manager for working with trees of objects.
  38. """
  39. def init_from_model(self, model):
  40. """
  41. Sets things up. This would normally be done in contribute_to_class(),
  42. but Django calls that before we've created our extra tree fields on the
  43. model (which we need). So it's done here instead, after field setup.
  44. """
  45. # Avoid calling "get_field_by_name()", which populates the related
  46. # models cache and can cause circular imports in complex projects.
  47. # Instead, find the tree_id field using "get_fields_with_model()".
  48. [tree_field] = [fld for fld in model._meta.get_fields_with_model() if fld[0].name == self.tree_id_attr]
  49. if tree_field[1]:
  50. # tree_model is the model that contains the tree fields.
  51. # this is usually just the same as model, but not for derived models.
  52. self.tree_model = tree_field[1]
  53. else:
  54. self.tree_model = model
  55. self._base_manager = None
  56. if self.tree_model is not model:
  57. # _base_manager is the treemanager on tree_model
  58. self._base_manager = self.tree_model._tree_manager
  59. @property
  60. def parent_attr(self):
  61. return self.model._mptt_meta.parent_attr
  62. @property
  63. def left_attr(self):
  64. return self.model._mptt_meta.left_attr
  65. @property
  66. def right_attr(self):
  67. return self.model._mptt_meta.right_attr
  68. @property
  69. def tree_id_attr(self):
  70. return self.model._mptt_meta.tree_id_attr
  71. @property
  72. def level_attr(self):
  73. return self.model._mptt_meta.level_attr
  74. def _translate_lookups(self, **lookups):
  75. new_lookups = {}
  76. for k, v in lookups.items():
  77. parts = k.split('__')
  78. new_parts = []
  79. for part in parts:
  80. new_parts.append(getattr(self, '%s_attr' % part, part))
  81. new_lookups['__'.join(new_parts)] = v
  82. return new_lookups
  83. def _mptt_filter(self, qs=None, **filters):
  84. """
  85. Like self.filter(), but translates name-agnostic filters for MPTT fields.
  86. """
  87. if self._base_manager:
  88. return self._base_manager._mptt_filter(qs=qs, **filters)
  89. if qs is None:
  90. qs = self.get_query_set()
  91. return qs.filter(**self._translate_lookups(**filters))
  92. def _mptt_update(self, qs=None, **items):
  93. """
  94. Like self.update(), but translates name-agnostic MPTT fields.
  95. """
  96. if self._base_manager:
  97. return self._base_manager._mptt_update(qs=qs, **items)
  98. if qs is None:
  99. qs = self.get_query_set()
  100. return qs.update(**self._translate_lookups(**items))
  101. def _get_connection(self, node):
  102. if connections is None:
  103. return connection
  104. else:
  105. return connections[router.db_for_write(node)]
  106. def add_related_count(self, queryset, rel_model, rel_field, count_attr,
  107. cumulative=False):
  108. """
  109. Adds a related item count to a given ``QuerySet`` using its
  110. ``extra`` method, for a ``Model`` class which has a relation to
  111. this ``Manager``'s ``Model`` class.
  112. Arguments:
  113. ``rel_model``
  114. A ``Model`` class which has a relation to this `Manager``'s
  115. ``Model`` class.
  116. ``rel_field``
  117. The name of the field in ``rel_model`` which holds the
  118. relation.
  119. ``count_attr``
  120. The name of an attribute which should be added to each item in
  121. this ``QuerySet``, containing a count of how many instances
  122. of ``rel_model`` are related to it through ``rel_field``.
  123. ``cumulative``
  124. If ``True``, the count will be for each item and all of its
  125. descendants, otherwise it will be for each item itself.
  126. """
  127. meta = self.model._meta
  128. if cumulative:
  129. subquery = CUMULATIVE_COUNT_SUBQUERY % {
  130. 'rel_table': qn(rel_model._meta.db_table),
  131. 'mptt_fk': qn(rel_model._meta.get_field(rel_field).column),
  132. 'mptt_table': qn(self.tree_model._meta.db_table),
  133. 'mptt_pk': qn(meta.pk.column),
  134. 'tree_id': qn(meta.get_field(self.tree_id_attr).column),
  135. 'left': qn(meta.get_field(self.left_attr).column),
  136. 'right': qn(meta.get_field(self.right_attr).column),
  137. }
  138. else:
  139. subquery = COUNT_SUBQUERY % {
  140. 'rel_table': qn(rel_model._meta.db_table),
  141. 'mptt_fk': qn(rel_model._meta.get_field(rel_field).column),
  142. 'mptt_table': qn(self.tree_model._meta.db_table),
  143. 'mptt_pk': qn(meta.pk.column),
  144. }
  145. return queryset.extra(select={count_attr: subquery})
  146. def get_query_set(self):
  147. """
  148. Returns a ``QuerySet`` which contains all tree items, ordered in
  149. such a way that that root nodes appear in tree id order and
  150. their subtrees appear in depth-first order.
  151. """
  152. return super(TreeManager, self).get_query_set().order_by(
  153. self.tree_id_attr, self.left_attr)
  154. def insert_node(self, node, target, position='last-child', save=False, allow_existing_pk=False):
  155. """
  156. Sets up the tree state for ``node`` (which has not yet been
  157. inserted into in the database) so it will be positioned relative
  158. to a given ``target`` node as specified by ``position`` (when
  159. appropriate) it is inserted, with any neccessary space already
  160. having been made for it.
  161. A ``target`` of ``None`` indicates that ``node`` should be
  162. the last root node.
  163. If ``save`` is ``True``, ``node``'s ``save()`` method will be
  164. called before it is returned.
  165. NOTE: This is a low-level method; it does NOT respect ``MPTTMeta.order_insertion_by``.
  166. In most cases you should just set the node's parent and let mptt call this during save.
  167. """
  168. if self._base_manager:
  169. return self._base_manager.insert_node(node, target, position=position, save=save)
  170. if node.pk and not allow_existing_pk and _exists(self.filter(pk=node.pk)):
  171. raise ValueError(_('Cannot insert a node which has already been saved.'))
  172. if target is None:
  173. setattr(node, self.left_attr, 1)
  174. setattr(node, self.right_attr, 2)
  175. setattr(node, self.level_attr, 0)
  176. setattr(node, self.tree_id_attr, self._get_next_tree_id())
  177. setattr(node, self.parent_attr, None)
  178. elif target.is_root_node() and position in ['left', 'right']:
  179. target_tree_id = getattr(target, self.tree_id_attr)
  180. if position == 'left':
  181. tree_id = target_tree_id
  182. space_target = target_tree_id - 1
  183. else:
  184. tree_id = target_tree_id + 1
  185. space_target = target_tree_id
  186. self._create_tree_space(space_target)
  187. setattr(node, self.left_attr, 1)
  188. setattr(node, self.right_attr, 2)
  189. setattr(node, self.level_attr, 0)
  190. setattr(node, self.tree_id_attr, tree_id)
  191. setattr(node, self.parent_attr, None)
  192. else:
  193. setattr(node, self.left_attr, 0)
  194. setattr(node, self.level_attr, 0)
  195. space_target, level, left, parent, right_shift = \
  196. self._calculate_inter_tree_move_values(node, target, position)
  197. tree_id = getattr(parent, self.tree_id_attr)
  198. self._create_space(2, space_target, tree_id)
  199. setattr(node, self.left_attr, -left)
  200. setattr(node, self.right_attr, -left + 1)
  201. setattr(node, self.level_attr, -level)
  202. setattr(node, self.tree_id_attr, tree_id)
  203. setattr(node, self.parent_attr, parent)
  204. if parent:
  205. self._post_insert_update_cached_parent_right(parent, right_shift)
  206. if save:
  207. node.save()
  208. return node
  209. def move_node(self, node, target, position='last-child'):
  210. """
  211. Moves ``node`` relative to a given ``target`` node as specified
  212. by ``position`` (when appropriate), by examining both nodes and
  213. calling the appropriate method to perform the move.
  214. A ``target`` of ``None`` indicates that ``node`` should be
  215. turned into a root node.
  216. Valid values for ``position`` are ``'first-child'``,
  217. ``'last-child'``, ``'left'`` or ``'right'``.
  218. ``node`` will be modified to reflect its new tree state in the
  219. database.
  220. This method explicitly checks for ``node`` being made a sibling
  221. of a root node, as this is a special case due to our use of tree
  222. ids to order root nodes.
  223. NOTE: This is a low-level method; it does NOT respect ``MPTTMeta.order_insertion_by``.
  224. In most cases you should just move the node yourself by setting node.parent.
  225. """
  226. if self._base_manager:
  227. return self._base_manager.move_node(node, target, position=position)
  228. if target is None:
  229. if node.is_child_node():
  230. self._make_child_root_node(node)
  231. elif target.is_root_node() and position in ['left', 'right']:
  232. self._make_sibling_of_root_node(node, target, position)
  233. else:
  234. if node.is_root_node():
  235. self._move_root_node(node, target, position)
  236. else:
  237. self._move_child_node(node, target, position)
  238. transaction.commit_unless_managed()
  239. def root_node(self, tree_id):
  240. """
  241. Returns the root node of the tree with the given id.
  242. """
  243. if self._base_manager:
  244. return self._base_manager.root_node(tree_id)
  245. return self._mptt_filter(tree_id=tree_id, parent__isnull=True).get()
  246. def root_nodes(self):
  247. """
  248. Creates a ``QuerySet`` containing root nodes.
  249. """
  250. if self._base_manager:
  251. return self._base_manager.root_nodes()
  252. return self._mptt_filter(parent__isnull=True)
  253. def rebuild(self):
  254. """
  255. Rebuilds whole tree in database using `parent` link.
  256. """
  257. if self._base_manager:
  258. return self._base_manager.rebuild()
  259. opts = self.model._mptt_meta
  260. qs = self._mptt_filter(parent__isnull=True)
  261. if opts.order_insertion_by:
  262. qs = qs.order_by(*opts.order_insertion_by)
  263. pks = qs.values_list('pk', flat=True)
  264. idx = 0
  265. for pk in pks:
  266. idx += 1
  267. self._rebuild_helper(pk, 1, idx)
  268. def _post_insert_update_cached_parent_right(self, instance, right_shift):
  269. setattr(instance, self.right_attr, getattr(instance, self.right_attr) + right_shift)
  270. attr = '_%s_cache' % self.parent_attr
  271. if hasattr(instance, attr):
  272. parent = getattr(instance, attr)
  273. if parent:
  274. self._post_insert_update_cached_parent_right(parent, right_shift)
  275. def _rebuild_helper(self, pk, left, tree_id, level=0):
  276. opts = self.model._mptt_meta
  277. right = left + 1
  278. qs = self._mptt_filter(parent__pk=pk)
  279. if opts.order_insertion_by:
  280. qs = qs.order_by(*opts.order_insertion_by)
  281. child_ids = qs.values_list('pk', flat=True)
  282. for child_id in child_ids:
  283. right = self._rebuild_helper(child_id, right, tree_id, level + 1)
  284. qs = self.model._default_manager.filter(pk=pk)
  285. self._mptt_update(qs,
  286. left=left,
  287. right=right,
  288. level=level,
  289. tree_id=tree_id
  290. )
  291. return right + 1
  292. def _calculate_inter_tree_move_values(self, node, target, position):
  293. """
  294. Calculates values required when moving ``node`` relative to
  295. ``target`` as specified by ``position``.
  296. """
  297. left = getattr(node, self.left_attr)
  298. level = getattr(node, self.level_attr)
  299. target_left = getattr(target, self.left_attr)
  300. target_right = getattr(target, self.right_attr)
  301. target_level = getattr(target, self.level_attr)
  302. if position == 'last-child' or position == 'first-child':
  303. if position == 'last-child':
  304. space_target = target_right - 1
  305. else:
  306. space_target = target_left
  307. level_change = level - target_level - 1
  308. parent = target
  309. elif position == 'left' or position == 'right':
  310. if position == 'left':
  311. space_target = target_left - 1
  312. else:
  313. space_target = target_right
  314. level_change = level - target_level
  315. parent = getattr(target, self.parent_attr)
  316. else:
  317. raise ValueError(_('An invalid position was given: %s.') % position)
  318. left_right_change = left - space_target - 1
  319. right_shift = 0
  320. if parent:
  321. right_shift = 2 * (node.get_descendant_count() + 1)
  322. return space_target, level_change, left_right_change, parent, right_shift
  323. def _close_gap(self, size, target, tree_id):
  324. """
  325. Closes a gap of a certain ``size`` after the given ``target``
  326. point in the tree identified by ``tree_id``.
  327. """
  328. self._manage_space(-size, target, tree_id)
  329. def _create_space(self, size, target, tree_id):
  330. """
  331. Creates a space of a certain ``size`` after the given ``target``
  332. point in the tree identified by ``tree_id``.
  333. """
  334. self._manage_space(size, target, tree_id)
  335. def _create_tree_space(self, target_tree_id):
  336. """
  337. Creates space for a new tree by incrementing all tree ids
  338. greater than ``target_tree_id``.
  339. """
  340. qs = self._mptt_filter(tree_id__gt=target_tree_id)
  341. self._mptt_update(qs, tree_id=F(self.tree_id_attr) + 1)
  342. def _get_next_tree_id(self):
  343. """
  344. Determines the next largest unused tree id for the tree managed
  345. by this manager.
  346. """
  347. qs = self.get_query_set()
  348. max_tree_id = qs.aggregate(Max(self.tree_id_attr)).values()[0]
  349. max_tree_id = max_tree_id or 0
  350. return max_tree_id + 1
  351. def _inter_tree_move_and_close_gap(self, node, level_change,
  352. left_right_change, new_tree_id, parent_pk=None):
  353. """
  354. Removes ``node`` from its current tree, with the given set of
  355. changes being applied to ``node`` and its descendants, closing
  356. the gap left by moving ``node`` as it does so.
  357. If ``parent_pk`` is ``None``, this indicates that ``node`` is
  358. being moved to a brand new tree as its root node, and will thus
  359. have its parent field set to ``NULL``. Otherwise, ``node`` will
  360. have ``parent_pk`` set for its parent field.
  361. """
  362. opts = self.model._meta
  363. inter_tree_move_query = """
  364. UPDATE %(table)s
  365. SET %(level)s = CASE
  366. WHEN %(left)s >= %%s AND %(left)s <= %%s
  367. THEN %(level)s - %%s
  368. ELSE %(level)s END,
  369. %(tree_id)s = CASE
  370. WHEN %(left)s >= %%s AND %(left)s <= %%s
  371. THEN %%s
  372. ELSE %(tree_id)s END,
  373. %(left)s = CASE
  374. WHEN %(left)s >= %%s AND %(left)s <= %%s
  375. THEN %(left)s - %%s
  376. WHEN %(left)s > %%s
  377. THEN %(left)s - %%s
  378. ELSE %(left)s END,
  379. %(right)s = CASE
  380. WHEN %(right)s >= %%s AND %(right)s <= %%s
  381. THEN %(right)s - %%s
  382. WHEN %(right)s > %%s
  383. THEN %(right)s - %%s
  384. ELSE %(right)s END,
  385. %(parent)s = CASE
  386. WHEN %(pk)s = %%s
  387. THEN %(new_parent)s
  388. ELSE %(parent)s END
  389. WHERE %(tree_id)s = %%s""" % {
  390. 'table': qn(self.tree_model._meta.db_table),
  391. 'level': qn(opts.get_field(self.level_attr).column),
  392. 'left': qn(opts.get_field(self.left_attr).column),
  393. 'tree_id': qn(opts.get_field(self.tree_id_attr).column),
  394. 'right': qn(opts.get_field(self.right_attr).column),
  395. 'parent': qn(opts.get_field(self.parent_attr).column),
  396. 'pk': qn(opts.pk.column),
  397. 'new_parent': parent_pk is None and 'NULL' or '%s',
  398. }
  399. left = getattr(node, self.left_attr)
  400. right = getattr(node, self.right_attr)
  401. gap_size = right - left + 1
  402. gap_target_left = left - 1
  403. params = [
  404. left, right, level_change,
  405. left, right, new_tree_id,
  406. left, right, left_right_change,
  407. gap_target_left, gap_size,
  408. left, right, left_right_change,
  409. gap_target_left, gap_size,
  410. node.pk,
  411. getattr(node, self.tree_id_attr)
  412. ]
  413. if parent_pk is not None:
  414. params.insert(-1, parent_pk)
  415. cursor = self._get_connection(node).cursor()
  416. cursor.execute(inter_tree_move_query, params)
  417. def _make_child_root_node(self, node, new_tree_id=None):
  418. """
  419. Removes ``node`` from its tree, making it the root node of a new
  420. tree.
  421. If ``new_tree_id`` is not specified a new tree id will be
  422. generated.
  423. ``node`` will be modified to reflect its new tree state in the
  424. database.
  425. """
  426. left = getattr(node, self.left_attr)
  427. right = getattr(node, self.right_attr)
  428. level = getattr(node, self.level_attr)
  429. if not new_tree_id:
  430. new_tree_id = self._get_next_tree_id()
  431. left_right_change = left - 1
  432. self._inter_tree_move_and_close_gap(node, level, left_right_change,
  433. new_tree_id)
  434. # Update the node to be consistent with the updated
  435. # tree in the database.
  436. setattr(node, self.left_attr, left - left_right_change)
  437. setattr(node, self.right_attr, right - left_right_change)
  438. setattr(node, self.level_attr, 0)
  439. setattr(node, self.tree_id_attr, new_tree_id)
  440. setattr(node, self.parent_attr, None)
  441. node._mptt_cached_fields[self.parent_attr] = None
  442. def _make_sibling_of_root_node(self, node, target, position):
  443. """
  444. Moves ``node``, making it a sibling of the given ``target`` root
  445. node as specified by ``position``.
  446. ``node`` will be modified to reflect its new tree state in the
  447. database.
  448. Since we use tree ids to reduce the number of rows affected by
  449. tree mangement during insertion and deletion, root nodes are not
  450. true siblings; thus, making an item a sibling of a root node is
  451. a special case which involves shuffling tree ids around.
  452. """
  453. if node == target:
  454. raise InvalidMove(_('A node may not be made a sibling of itself.'))
  455. opts = self.model._meta
  456. tree_id = getattr(node, self.tree_id_attr)
  457. target_tree_id = getattr(target, self.tree_id_attr)
  458. if node.is_child_node():
  459. if position == 'left':
  460. space_target = target_tree_id - 1
  461. new_tree_id = target_tree_id
  462. elif position == 'right':
  463. space_target = target_tree_id
  464. new_tree_id = target_tree_id + 1
  465. else:
  466. raise ValueError(_('An invalid position was given: %s.') % position)
  467. self._create_tree_space(space_target)
  468. if tree_id > space_target:
  469. # The node's tree id has been incremented in the
  470. # database - this change must be reflected in the node
  471. # object for the method call below to operate on the
  472. # correct tree.
  473. setattr(node, self.tree_id_attr, tree_id + 1)
  474. self._make_child_root_node(node, new_tree_id)
  475. else:
  476. if position == 'left':
  477. if target_tree_id > tree_id:
  478. left_sibling = target.get_previous_sibling()
  479. if node == left_sibling:
  480. return
  481. new_tree_id = getattr(left_sibling, self.tree_id_attr)
  482. lower_bound, upper_bound = tree_id, new_tree_id
  483. shift = -1
  484. else:
  485. new_tree_id = target_tree_id
  486. lower_bound, upper_bound = new_tree_id, tree_id
  487. shift = 1
  488. elif position == 'right':
  489. if target_tree_id > tree_id:
  490. new_tree_id = target_tree_id
  491. lower_bound, upper_bound = tree_id, target_tree_id
  492. shift = -1
  493. else:
  494. right_sibling = target.get_next_sibling()
  495. if node == right_sibling:
  496. return
  497. new_tree_id = getattr(right_sibling, self.tree_id_attr)
  498. lower_bound, upper_bound = new_tree_id, tree_id
  499. shift = 1
  500. else:
  501. raise ValueError(_('An invalid position was given: %s.') % position)
  502. root_sibling_query = """
  503. UPDATE %(table)s
  504. SET %(tree_id)s = CASE
  505. WHEN %(tree_id)s = %%s
  506. THEN %%s
  507. ELSE %(tree_id)s + %%s END
  508. WHERE %(tree_id)s >= %%s AND %(tree_id)s <= %%s""" % {
  509. 'table': qn(self.tree_model._meta.db_table),
  510. 'tree_id': qn(opts.get_field(self.tree_id_attr).column),
  511. }
  512. cursor = self._get_connection(node).cursor()
  513. cursor.execute(root_sibling_query, [tree_id, new_tree_id, shift,
  514. lower_bound, upper_bound])
  515. setattr(node, self.tree_id_attr, new_tree_id)
  516. def _manage_space(self, size, target, tree_id):
  517. """
  518. Manages spaces in the tree identified by ``tree_id`` by changing
  519. the values of the left and right columns by ``size`` after the
  520. given ``target`` point.
  521. """
  522. opts = self.model._meta
  523. space_query = """
  524. UPDATE %(table)s
  525. SET %(left)s = CASE
  526. WHEN %(left)s > %%s
  527. THEN %(left)s + %%s
  528. ELSE %(left)s END,
  529. %(right)s = CASE
  530. WHEN %(right)s > %%s
  531. THEN %(right)s + %%s
  532. ELSE %(right)s END
  533. WHERE %(tree_id)s = %%s
  534. AND (%(left)s > %%s OR %(right)s > %%s)""" % {
  535. 'table': qn(self.tree_model._meta.db_table),
  536. 'left': qn(opts.get_field(self.left_attr).column),
  537. 'right': qn(opts.get_field(self.right_attr).column),
  538. 'tree_id': qn(opts.get_field(self.tree_id_attr).column),
  539. }
  540. cursor = self._get_connection(self.model).cursor()
  541. cursor.execute(space_query, [target, size, target, size, tree_id,
  542. target, target])
  543. def _move_child_node(self, node, target, position):
  544. """
  545. Calls the appropriate method to move child node ``node``
  546. relative to the given ``target`` node as specified by
  547. ``position``.
  548. """
  549. tree_id = getattr(node, self.tree_id_attr)
  550. target_tree_id = getattr(target, self.tree_id_attr)
  551. if tree_id == target_tree_id:
  552. self._move_child_within_tree(node, target, position)
  553. else:
  554. self._move_child_to_new_tree(node, target, position)
  555. def _move_child_to_new_tree(self, node, target, position):
  556. """
  557. Moves child node ``node`` to a different tree, inserting it
  558. relative to the given ``target`` node in the new tree as
  559. specified by ``position``.
  560. ``node`` will be modified to reflect its new tree state in the
  561. database.
  562. """
  563. left = getattr(node, self.left_attr)
  564. right = getattr(node, self.right_attr)
  565. level = getattr(node, self.level_attr)
  566. new_tree_id = getattr(target, self.tree_id_attr)
  567. space_target, level_change, left_right_change, parent, new_parent_right = \
  568. self._calculate_inter_tree_move_values(node, target, position)
  569. tree_width = right - left + 1
  570. # Make space for the subtree which will be moved
  571. self._create_space(tree_width, space_target, new_tree_id)
  572. # Move the subtree
  573. self._inter_tree_move_and_close_gap(node, level_change,
  574. left_right_change, new_tree_id, parent.pk)
  575. # Update the node to be consistent with the updated
  576. # tree in the database.
  577. setattr(node, self.left_attr, left - left_right_change)
  578. setattr(node, self.right_attr, right - left_right_change)
  579. setattr(node, self.level_attr, level - level_change)
  580. setattr(node, self.tree_id_attr, new_tree_id)
  581. setattr(node, self.parent_attr, parent)
  582. node._mptt_cached_fields[self.parent_attr] = parent.pk
  583. def _move_child_within_tree(self, node, target, position):
  584. """
  585. Moves child node ``node`` within its current tree relative to
  586. the given ``target`` node as specified by ``position``.
  587. ``node`` will be modified to reflect its new tree state in the
  588. database.
  589. """
  590. left = getattr(node, self.left_attr)
  591. right = getattr(node, self.right_attr)
  592. level = getattr(node, self.level_attr)
  593. width = right - left + 1
  594. tree_id = getattr(node, self.tree_id_attr)
  595. target_left = getattr(target, self.left_attr)
  596. target_right = getattr(target, self.right_attr)
  597. target_level = getattr(target, self.level_attr)
  598. if position == 'last-child' or position == 'first-child':
  599. if node == target:
  600. raise InvalidMove(_('A node may not be made a child of itself.'))
  601. elif left < target_left < right:
  602. raise InvalidMove(_('A node may not be made a child of any of its descendants.'))
  603. if position == 'last-child':
  604. if target_right > right:
  605. new_left = target_right - width
  606. new_right = target_right - 1
  607. else:
  608. new_left = target_right
  609. new_right = target_right + width - 1
  610. else:
  611. if target_left > left:
  612. new_left = target_left - width + 1
  613. new_right = target_left
  614. else:
  615. new_left = target_left + 1
  616. new_right = target_left + width
  617. level_change = level - target_level - 1
  618. parent = target
  619. elif position == 'left' or position == 'right':
  620. if node == target:
  621. raise InvalidMove(_('A node may not be made a sibling of itself.'))
  622. elif left < target_left < right:
  623. raise InvalidMove(_('A node may not be made a sibling of any of its descendants.'))
  624. if position == 'left':
  625. if target_left > left:
  626. new_left = target_left - width
  627. new_right = target_left - 1
  628. else:
  629. new_left = target_left
  630. new_right = target_left + width - 1
  631. else:
  632. if target_right > right:
  633. new_left = target_right - width + 1
  634. new_right = target_right
  635. else:
  636. new_left = target_right + 1
  637. new_right = target_right + width
  638. level_change = level - target_level
  639. parent = getattr(target, self.parent_attr)
  640. else:
  641. raise ValueError(_('An invalid position was given: %s.') % position)
  642. left_boundary = min(left, new_left)
  643. right_boundary = max(right, new_right)
  644. left_right_change = new_left - left
  645. gap_size = width
  646. if left_right_change > 0:
  647. gap_size = -gap_size
  648. opts = self.model._meta
  649. # The level update must come before the left update to keep
  650. # MySQL happy - left seems to refer to the updated value
  651. # immediately after its update has been specified in the query
  652. # with MySQL, but not with SQLite or Postgres.
  653. move_subtree_query = """
  654. UPDATE %(table)s
  655. SET %(level)s = CASE
  656. WHEN %(left)s >= %%s AND %(left)s <= %%s
  657. THEN %(level)s - %%s
  658. ELSE %(level)s END,
  659. %(left)s = CASE
  660. WHEN %(left)s >= %%s AND %(left)s <= %%s
  661. THEN %(left)s + %%s
  662. WHEN %(left)s >= %%s AND %(left)s <= %%s
  663. THEN %(left)s + %%s
  664. ELSE %(left)s END,
  665. %(right)s = CASE
  666. WHEN %(right)s >= %%s AND %(right)s <= %%s
  667. THEN %(right)s + %%s
  668. WHEN %(right)s >= %%s AND %(right)s <= %%s
  669. THEN %(right)s + %%s
  670. ELSE %(right)s END,
  671. %(parent)s = CASE
  672. WHEN %(pk)s = %%s
  673. THEN %%s
  674. ELSE %(parent)s END
  675. WHERE %(tree_id)s = %%s""" % {
  676. 'table': qn(self.tree_model._meta.db_table),
  677. 'level': qn(opts.get_field(self.level_attr).column),
  678. 'left': qn(opts.get_field(self.left_attr).column),
  679. 'right': qn(opts.get_field(self.right_attr).column),
  680. 'parent': qn(opts.get_field(self.parent_attr).column),
  681. 'pk': qn(opts.pk.column),
  682. 'tree_id': qn(opts.get_field(self.tree_id_attr).column),
  683. }
  684. cursor = self._get_connection(node).cursor()
  685. cursor.execute(move_subtree_query, [
  686. left, right, level_change,
  687. left, right, left_right_change,
  688. left_boundary, right_boundary, gap_size,
  689. left, right, left_right_change,
  690. left_boundary, right_boundary, gap_size,
  691. node.pk, parent.pk,
  692. tree_id])
  693. # Update the node to be consistent with the updated
  694. # tree in the database.
  695. setattr(node, self.left_attr, new_left)
  696. setattr(node, self.right_attr, new_right)
  697. setattr(node, self.level_attr, level - level_change)
  698. setattr(node, self.parent_attr, parent)
  699. node._mptt_cached_fields[self.parent_attr] = parent.pk
  700. def _move_root_node(self, node, target, position):
  701. """
  702. Moves root node``node`` to a different tree, inserting it
  703. relative to the given ``target`` node as specified by
  704. ``position``.
  705. ``node`` will be modified to reflect its new tree state in the
  706. database.
  707. """
  708. left = getattr(node, self.left_attr)
  709. right = getattr(node, self.right_attr)
  710. level = getattr(node, self.level_attr)
  711. tree_id = getattr(node, self.tree_id_attr)
  712. new_tree_id = getattr(target, self.tree_id_attr)
  713. width = right - left + 1
  714. if node == target:
  715. raise InvalidMove(_('A node may not be made a child of itself.'))
  716. elif tree_id == new_tree_id:
  717. raise InvalidMove(_('A node may not be made a child of any of its descendants.'))
  718. space_target, level_change, left_right_change, parent, right_shift = \
  719. self._calculate_inter_tree_move_values(node, target, position)
  720. # Create space for the tree which will be inserted
  721. self._create_space(width, space_target, new_tree_id)
  722. # Move the root node, making it a child node
  723. opts = self.model._meta
  724. move_tree_query = """
  725. UPDATE %(table)s
  726. SET %(level)s = %(level)s - %%s,
  727. %(left)s = %(left)s - %%s,
  728. %(right)s = %(right)s - %%s,
  729. %(tree_id)s = %%s,
  730. %(parent)s = CASE
  731. WHEN %(pk)s = %%s
  732. THEN %%s
  733. ELSE %(parent)s END
  734. WHERE %(left)s >= %%s AND %(left)s <= %%s
  735. AND %(tree_id)s = %%s""" % {
  736. 'table': qn(self.tree_model._meta.db_table),
  737. 'level': qn(opts.get_field(self.level_attr).column),
  738. 'left': qn(opts.get_field(self.left_attr).column),
  739. 'right': qn(opts.get_field(self.right_attr).column),
  740. 'tree_id': qn(opts.get_field(self.tree_id_attr).column),
  741. 'parent': qn(opts.get_field(self.parent_attr).column),
  742. 'pk': qn(opts.pk.column),
  743. }
  744. cursor = self._get_connection(node).cursor()
  745. cursor.execute(move_tree_query, [level_change, left_right_change,
  746. left_right_change, new_tree_id, node.pk, parent.pk, left, right,
  747. tree_id])
  748. # Update the former root node to be consistent with the updated
  749. # tree in the database.
  750. setattr(node, self.left_attr, left - left_right_change)
  751. setattr(node, self.right_attr, right - left_right_change)
  752. setattr(node, self.level_attr, level - level_change)
  753. setattr(node, self.tree_id_attr, new_tree_id)
  754. setattr(node, self.parent_attr, parent)
  755. node._mptt_cached_fields[self.parent_attr] = parent.pk