Programming

UPDATE: Starting with version 2.0.2, Yii2 Advanced Template does not contain “role” column in the User table by default. Before proceeding to the tutorial below, do the following:

Create a column called role in the user table.
Update the User model by adding the role attribute and updating the User class docblock accordingly.

Yii 2.0 has a built in Access Control that supports 2 roles out of the box to check whether the user is a guest or if the user is logged in. Sometimes there is a need to simply extend the Access Control Layer with few more roles to distinguish the logged in users i.e. admin, moderator, without the full blown RBAC graph with permissions, roles and role assignments that Yii provides.

In this post, I will show how to implement simple Role Based authorization by simply extending the AccessRule class that defines the default rules and overriding the matchRule() function call, which will provide the additional rule matching logic. Continue reading Simpler Role Based Authorization in Yii 2.0

Here I will share a very basic UDP chat application in Python using sockets.

It can work in point-to-point or broadcast mode.

For Point-to-Point, enter IP and Port.

For Broadcasting mode set the last byte of IP address to 255. i.e. 192.168.0.255.

Port number is HEX, remove the base 16 to make it decimal.

#!/usr/bin/env python
import socket
import sys, select
 
# Read a line. Using select for non blocking reading of sys.stdin
def getLine():
    i,o,e = select.select([sys.stdin],[],[],0.0001)
    for s in i:
        if s == sys.stdin:
            input = sys.stdin.readline()
            return input
    return False
 
host = raw_input("Please Enter IP: ")
port = int(raw_input("Please Enter PORT: "), 16) # Base 16 for hex value
 
send_address = (host, port) # Set the address to send to
s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)    # Create Datagram Socket (UDP)
s.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1) # Make Socket Reusable
s.setsockopt(socket.SOL_SOCKET, socket.SO_BROADCAST, 1) # Allow incoming broadcasts
s.setblocking(False) # Set socket to non-blocking mode
s.bind(('', port)) #Accept Connections on port
print "Accepting connections on port", hex(port)
 
while 1:
    try:
        message, address = s.recvfrom(8192) # Buffer size is 8192. Change as needed.
        if message:
            print address, "> ", message
    except:
        pass
 
    input = getLine();
    if(input != False):
        s.sendto(input, send_address)

#!/usr/bin/env python

import socket

import sys, select

# Read a line. Using select for non blocking reading of sys.stdin

def getLine():

i,o,e = select.select([sys.stdin],[],[],0.0001)

for s in i:

if s == sys.stdin:

input = sys.stdin.readline()

return input

return False

host = raw_input("Please Enter IP: ")

port = int(raw_input("Please Enter PORT: "), 16) # Base 16 for hex value

send_address = (host, port) # Set the address to send to

s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM) # Create Datagram Socket (UDP)

s.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1) # Make Socket Reusable

s.setsockopt(socket.SOL_SOCKET, socket.SO_BROADCAST, 1) # Allow incoming broadcasts

s.setblocking(False) # Set socket to non-blocking mode

s.bind(('', port)) #Accept Connections on port

print "Accepting connections on port", hex(port)

while 1:

try:

message, address = s.recvfrom(8192) # Buffer size is 8192. Change as needed.

if message:

print address, "> ", message

except:

pass

input = getLine();

if(input != False):

s.sendto(input, send_address)

Tag: Programming

Simpler Role Based Authorization in Yii 2.0

UDP Chat in Python Using Socket