- for using in some queries like direct children (just too lazy to think how to use lft and rgt :) ) - cascade delete (if is supported by the database)
On Mon, Nov 9, 2009 at 1:18 AM, mdipierro <[email protected]> wrote: > > what do you need parent_id for when you have lgt and rgt? > > > > On Nov 8, 5:10 pm, elffikk <[email protected]> wrote: > > Hi, > > > > I started a nested sets implementation > > Just sharing the code. I welcome any thoughts you have > > > > 2 files - nstree_controller (just quick and dirty tests of the model), > > and nstree_model > > > > [nstree_controller :] > > > > t1 = nstree(db, db.tree1) > > > > def index(): > > return dict(message="Version " + nstree.version) > > > > def test_path(): > > _id = 33 > > return dict(message = " > ".join([node.name for node in t1.path > > (_id)])) > > > > def test_removetree(): > > _id = request.vars.id if request.vars.id else 3 > > t1.remove_tree(_id) > > return dict(message="Success") > > > > def test_delete(): > > _id = request.vars.id if request.vars.id else 19 > > node = t1.delete(_id) > > return dict(message= node.name + " deleted ") > > > > def test_get(): > > _id = request.vars.id if request.vars.id else 15 > > #nodes = t1.ancestors(_id) > > #nodes = t1.descendants(_id) > > nodes = t1.children(_id) > > return dict(message= ", ".join([node.name for node in nodes])) > > > > def test_gettree(): > > root_id = request.vars.root_id if request.vars.root_id else 1 > > nodes = t1.tree(root_id) > > return dict(message="Count "+str(len(nodes))) > > > > def test_add(): > > root_id = request.vars.root_id if request.vars.root_id else > > t1.roots()[0].id > > r1 = t1.add(root_id, name='1') > > r2 = t1.add(root_id, name='2') > > r3 = t1.add(root_id, name='3') > > t1.add(r1, name='11') > > t1.add(r1, name='12') > > return dict(message="Success") > > > > def test_create_roots(): > > ''' > > t1.create_root(name='root1') > > t1.create_root(name='root2') > > t1.create_root(name='root3') > > t1.create_root(name='root4') > > ''' > > roots = t1.roots() > > return dict(message="Roots count : " + str(len(roots))) > > > > [nstree_model:] > > > > db.define_table('tree1', > > SQLField('name', "string", 128), > > SQLField('lft','integer'), > > SQLField('rgt','integer'), > > SQLField('level','integer'), > > SQLField('root_id','integer'), > > SQLField('parent_id','reference tree1'), > > ) > > # > > # A Nested Sets implementation > > # need to pass a table with following fields: > > # lft, rgt, level, parent_id, root_id - all fields of type int > > # ------- > > # Notes: > > # - table can contain multiple roots > > # > > class nstree: > > version = "1.0.0.04" > > def __init__(self, db, dbtable): > > self.db = db > > self.dbtable = dbtable > > #self.lft = dbtable.lft > > #self.rgt = dbtable.rgt > > #self.level = dbtable.level > > #self.parent_id = dbtable.parent_id > > #self.root_id = dbtable.root_id > > # > > # Methods for building tree (create, delete nodes) > > # > > def create_root(self, **fields): > > _id = self.dbtable.insert(lft=1, rgt=2, level=0, **fields) > > _root = self.dbtable[_id] > > _root.update_record(root_id = _id) > > return _root > > def add(self, parent_id, **fields): return self.add_last_child > > (parent_id, **fields) > > def add_last_child(self, parent_id, **fields): > > _parent = self.dbtable[parent_id] > > q1 = self.dbtable.rgt >= _parent.rgt > > q2 = self.dbtable.lft >= _parent.rgt > > q3 = self.dbtable.root_id == _parent.root_id > > self.db(q1)(q3).update(rgt=self.dbtable.rgt+2) > > self.db(q2)(q3).update(lft=self.dbtable.lft+2) > > return self.dbtable.insert( > > parent_id = parent_id, > > lft = _parent.rgt, > > rgt = _parent.rgt+1, > > level = _parent.level+1, > > root_id = _parent.root_id, > > **fields > > ) > > def delete(self, id): return self.remove(id) > > def remove(self, id): > > node = self.dbtable[id] > > delta = node.rgt - node.lft + 1 > > q1 = self.dbtable.lft >= node.lft > > q2 = self.dbtable.rgt <= node.rgt > > self.db(q1)(q2).delete() > > self.db(self.dbtable.lft > node.rgt).update(lft = > > self.dbtable.lft - delta) > > self.db(self.dbtable.rgt > node.rgt).update(rgt = > > self.dbtable.rgt - delta) > > return node > > def remove_descendants(self, id): > > node = self.dbtable[id] > > delta = node.rgt - node.lft + 1 > > q1 = self.dbtable.lft > node.lft > > q2 = self.dbtable.rgt < node.rgt > > self.db(q1)(q2).delete() > > self.db(self.dbtable.lft > node.rgt).update(lft = > > self.dbtable.lft - delta) > > self.db(self.dbtable.rgt > node.rgt).update(rgt = > > self.dbtable.rgt - delta) > > def remove_tree(self, id): > > self.db(self.dbtable.root_id == id).delete() > > # > > # Methods for retrieving nodes > > # > > def roots(self): return self.db(self.dbtable.lft == 1).select() > > def tree(self, root_id): return self.db(self.dbtable.root_id == > > root_id).select(orderby = self.dbtable.lft) > > def ancestors(self, id): > > node = self.dbtable[id] > > q1 = self.dbtable.lft < node.lft > > q2 = self.dbtable.rgt > node.rgt > > q3 = self.dbtable.root_id == node.root_id > > return self.db(q1)(q2)(q3).select(orderby = self.dbtable.lft) > > def path(self, id): > > node = self.dbtable[id] > > q1 = self.dbtable.lft <= node.lft > > q2 = self.dbtable.rgt >= node.rgt > > q3 = self.dbtable.root_id == node.root_id > > return self.db(q1)(q2)(q3).select(orderby = self.dbtable.lft) > > def descendants(self, id): > > node = self.dbtable[id] > > q1 = self.dbtable.lft > node.lft > > q2 = self.dbtable.rgt < node.rgt > > q3 = self.dbtable.root_id == node.root_id > > return self.db(q1)(q2)(q3).select(orderby = self.dbtable.lft) > > def children(self, id): return self.db(self.dbtable.parent_id == > > id).select(orderby = self.dbtable.lft) > > # > > # Methods for checking or getting state of node(s) > > # > > def num_children(self, node): return int((node.rgt-node.lft-1)/2) > > def is_root(self, node): return node.id == node.root_id > > def is_leaf(self, node): return node.lft == node.rgt-1 > > def is_child(self, node1, node2): return node1.lft > node2.lft > > and node1.rgt < node2.rgt > > > --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "web2py-users" group. 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