def follow_user(follower_name, user_name):
"""
:param follower_name:
:param user_name:
:return: True if Updated, else False
"""
if follower_name == user_name:
return False
user = ProfileService.get_profile(user_name)
follower = ProfileService.get_profile(follower_name)
if follower_name in user['followers']:
return True
if user and follower:
# add follower to user
USERS.find_one_and_update(
{"username": user_name},
{"$push": {"followers": follower_name}},
upsert=True)
# add follows to follower
USERS.find_one_and_update(
{"username": follower_name},
{"$push": {"follows": user_name}},
upsert=True)
# add neo4j relation
NEO4J.run("MATCH (a {username:$follower}), (b {username:$user}) "
"CREATE (a)-[:follows]->(b)",
{'follower': follower_name, 'user': user_name})
return True
return False
def create_neo_user(username):
"""
add user to neo4j
:param username:
:return:
"""
found = NEO4J.run("MATCH (u:User {username:$username}) "
"RETURN u", username=username)
if found.forward():
return None
user = NEO4J.run("CREATE (u:User {username:$username}) "
"RETURN u", {'username': username}).current
return user
def get_distance(user_from, user_to):
"""
get distance from one user to another
:param user_from:
:param user_to:
:return: list of usernames from shortest path or empty list if:
there is no path or > 10 nodes in path or both parameters are the same
"""
distance = []
if user_from != user_to:
result = NEO4J.run(
"MATCH p = shortestPath((f:User)-[*..10]-(t:User)) "
"WHERE f.username=$user_from AND t.username=$user_to RETURN p",
{
'user_from': user_from,
'user_to': user_to
})
if result.forward():
for node in result.current[0].nodes:
distance.append(node['username'])
distance.remove(user_from)
return distance
def unfollow_user(follower_name, user_name):
"""
:param follower_name:
:param user_name:
:return: True if Updated, else False
"""
if follower_name == user_name:
return False
user = ProfileService.get_profile(user_name)
follower = ProfileService.get_profile(follower_name)
if follower_name not in user['followers']:
return True
if user and follower:
USERS.find_one_and_update({"username": user_name},
{"$pull": {
"followers": follower_name
}},
upsert=True)
USERS.find_one_and_update({"username": follower_name},
{"$pull": {
"follows": user_name
}},
upsert=True)
# delete neo4j relation
NEO4J.run(
"MATCH (a {username:$follower})-[f:follows]->(b {username:$user}) DELETE f",
{
'follower': follower_name,
'user': user_name
})
return True
return False