Neo4J shennanigans

main.py

from functools import partial

from bulbs.neo4jserver import Graph
from bulbs.model import Node, Relationship
from bulbs.property import String, Integer

from sitemap import sitemap


class Page(Node):
    element_type = 'page'

    name = String(nullable=False)
    visibility = Integer()


class Links(Relationship):
    label = 'links'


def create_proxies(g):
    g.add_proxy('pages', Page)
    g.add_proxy('links', Links)


def iter_tree(tree, lvl=0, cb=None):
    print '\t' * lvl, tree[0]
    if cb:
        cb(*tree)
    for t in tree[1]:
        iter_tree(t, lvl+1, cb)


def get_or_create_by_name(g, name):
    return g.pages.get_or_create('name', name, {'name': name})


def create_link(g, name, children):
    root = get_or_create_by_name(g, name)
    for c in children:
        n = get_or_create_by_name(g, c[0])
        g.links.create(root, n)


UPDATE_VISIBILITY_QUERY = """
START home=node:page(name={home_name}),
      page=node(*)
MATCH path = shortestPath(home-[*]->page)
SET page.visibility = length(path);
"""


def update_visibility(g, home_name):
    g.client.cypher(UPDATE_VISIBILITY_QUERY, {'home_name': home_name})


def print_visibilities(g):
    for page in g.pages.get_all():
        print page.name, page.visibility


def main():
    print sitemap, '\n'
    print '-' * 10, '\n'

    g = Graph()
    create_proxies(g)

    # create home so get_or_create on create_link() is not necessary and only 1
    # query is needed for update_visibility.
    home_name = sitemap[0]
    g.pages.create(name=home_name, visibility=0)
    build_graph = partial(create_link, g)
    iter_tree(sitemap, cb=build_graph)

    update_visibility(g, home_name)

    print '-' * 10, '\n'
    print_visibilities(g)


if __name__ == '__main__':
    main()

sitemap.py

sitemap = \
['home', [
    ['categorias', [
        ['eletronicos', [
            ['tv', []],
            ['pc', []],
        ] ],
            
        ['casa', [
            ['cadeira', [] ],
            ['mesa', [] ],
            ['cama', [] ],
        ] ],
    ] ],

    ['descontos', [
        ['tv', []],  # visibility = 2
    ] ],
] ]