Saigon MD

Enhanced your programming skill with Assert and Unit Test Sources http://www.pgbovine.net/programming-with-asserts.htm http://stackoverflow.com/questions/1375786/whats-the-point-of-nsassert-actually https://www.youtube.com/watch?v=BbPPnxhcdHo Why you need Assert in your program? 1/ What is Assert? + Assert is the way you make sure a condition in your program must be matched. Otherwise, the app will crash. 2/ What is the point of Assertion? + Using assert will guarantee your program always act like your assumption. => For instance, you write a function with a lot of input and in some situation, inputs mus be valid. Let's say input_1 must comes with input_2. In that case, writing if else and return value is not fit, because you have to handle a lot of return value & error => So that, you will use Assert to make sure your function is used properly. This is very important when you working in a team while writing functions for other people to use. Or even if

Setup iOS APNS with HTTP/2 Overview: There're one issue while sending iOS notification to multiple devices with old method (send by ftp write stream). Let say you send to 100 devices, ftp write work likes this: 1. connect to APNS Server 2. for each device: send notification by using device_token & payload 3. disconnect In step 2, if there're 1 invalid token (there're many reason make a token invalid: expired, wrong cert, wrong format...etc) the connection will be block without status from APNS Server, if you want to check the status, you have to wait at least 0.5s-1s and using ftp-read to read the status. It's mean you have to check status after every ftp-write and re-connect again if there're an invalid token.  So, to send to 100 devices, you need 50 seconds, that's too long. At WWDC 2015, Apple has introduce a  new notification api by using HTTP/2 This api allow you to send notification as a post request or curl and get the result

Handle iOS Push Notification Handle push notification on iOS is quite hard if you don't understand it. In short topic, I on;y want to present how I handle when user tap on push notification when app is in active/background or killed. First, these are few important notes that you need to keep in mind: - APNS have sandbox & prod certificates, don't forget when you run the app in debug mode, you have to use sandbox. - The registration token cannot be shared, sandbox token cannot be use for prod and vice versa. Others tut: - Apple Documents -  APNS with HTTP2 Generate Push Certificate: cert_file="mobisys_prod_apns.cer" key_file="mobisys_prod_apns.p12" openssl x509 -in $cert_file -inform der -out pem_cert.pem openssl pkcs12 -nocerts -in $key_file -out pem_key.pem cat pem_cert.pem pem_key.pem > PushCert.pem Common Mistakes - using wrong certificate (APNS will return error) / wrong passphrase (in script will retunr error) - using in