It would be nice to implement in a general way so that once can do:
db.define_table('mytabletree',Field('data_at_node'),Tree
('mytabletree'))
where
class Tree:
def __call__(self,tablename):
return sql.Table(...)
other methods....
Hope it makes sense. Not sure how doable.
massimo
On Nov 8, 5:40 pm, Thadeus Burgess <[email protected]> wrote:
> Wow what timing, I was just about to post a similar thing :)
>
> http://pastebin.com/f4fc602d7
>
> -Thadeus
>
> On Sun, Nov 8, 2009 at 5:28 PM, Vasile Ermicioi <[email protected]> wrote:
> > - 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.
To post to this group, send email to [email protected]
To unsubscribe from this group, send email to
[email protected]
For more options, visit this group at
http://groups.google.com/group/web2py?hl=en
-~----------~----~----~----~------~----~------~--~---
