I have recently started doing development on the iPhone. It’s great fun. I am particularly interested in the Push aspect of this. I’m also a big fan of Python.
There’s a number of RESTful things that can be done with Ruby on Rails. However, the whole ‘packaged application’ thing is quite new to that framework. To Django, it’s the staple diet of how to get things done. So I’m currently part way through a generic application for Django for sending APN (Apple Push Notification) requests as well as dealing with the feedback connection.
Currently I have the push side working quite well. Just a warning, this is my first stab at this and it requires Python 2.6, or the relevant backports for ssl and json installed on 2.5.
from django.db import models
from django.conf import settings
from socket import socket
import datetime
import struct
import ssl
import binascii
import json
class iPhone(models.Model):
"""
Represents an iPhone used to push
udid - the iPhone Unique Push Identifier (64 chars of hex)
last_notified_at - when was a notification last sent to the phone
test_phone - is this a phone that should be included in test runs
notes - just a small notes field so that we can put in things like "Lee's iPhone"
failed_phone - Have we had feedback about this phone? If so, flag it.
"""
udid = models.CharField(blank=False, max_length=64)
last_notified_at = models.DateTimeField(blank=True, default=datetime.datetime.now)
test_phone = models.BooleanField(default=False)
notes = models.CharField(blank=True, max_length=100)
failed_phone = models.BooleanField(default=False)
class Admin:
list_display = ('',)
search_fields = ('',)
def send_message(self, alert, badge=0, sound="chime", sandbox=True,
custom_params={}, action_loc_key=None, loc_key=None,
loc_args=[], passed_socket=None):
"""
Send a message to an iPhone using the APN server, returns whether
it was successful or not.
alert - The message you want to send
badge - Numeric badge number you wish to show, 0 will clear it
sound - chime is shorter than default! Replace with None/"" for no sound
sandbox - Are you sending to the sandbox or the live server
custom_params - A dict of custom params you want to send
action_loc_key - As per APN docs
loc_key - As per APN docs
loc_args - As per APN docs, make sure you use a list
passed_socket - Rather than open/close a socket, use an already open one
This requires IPHONE_APN_PUSH_CERT in settings.py to be the full
path to the cert/pk .pem file.
"""
aps_payload = {}
alert_payload = alert
if action_loc_key or loc_key or loc_args:
alert_payload = {'body' : alert}
if action_loc_key:
alert_payload['action-loc-key'] = action_loc_key
if loc_key:
alert_payload['loc-key'] = loc_key
if loc_args:
alert_payload['loc-args'] = loc_args
aps_payload['alert'] = alert_payload
if badge:
aps_payload['badge'] = badge
if sound:
aps_payload['sound'] = sound
payload = custom_params
payload['aps'] = aps_payload
s_payload = json.dumps(payload, separators=(',',':'))
fmt = "!cH32sH%ds" % len(s_payload)
command = '\x00'
msg = struct.pack(fmt, command, 32, binascii.unhexlify(self.udid), len(s_payload), s_payload)
if passed_socket:
passed_socket.write(msg)
else:
host_name = 'gateway.sandbox.push.apple.com' if sandbox else 'gateway.push.apple.com'
s = socket()
c = ssl.wrap_socket(s,
ssl_version=ssl.PROTOCOL_SSLv3,
certfile=settings.IPHONE_APN_PUSH_CERT)
c.connect((host_name, 2195))
c.write(msg)
c.close()
return True
def __unicode__(self):
return u"iPhone %s" % self.udid
So how do we use it? Well rather easy. First you need to set up your certificates with Apple. You’ll need to set up a specific AppID and provisioning profile for your application (i.e. you can’t use *).
The guide on Apple’s site covers how to do this. Python needs it in a combined PEM format to work. Other sites claim you have to export from Keychain Access and that you’ll need to convert both to .pem. I only had to convert the private key:
openssl pkcs12 -in pkey.p12 -out pkey.pem -nodes -clcerts cat cert.pem pkey.pem > iphone_ck.pem
I then altered my settings.py to have the new entry I added:
IPHONE_APN_PUSH_CERT = os.path.join(PROJECT_ROOT, "iphone_ck.pem")
Note the full path. I always have this at the top of settings.py to make my like easier:
import os PROJECT_ROOT = os.path.abspath(os.path.dirname(__file__))
Now, it’s just case of making your iPhone app register with push and getting a unique ID. You have to use your real phone to do this. If you’re in a hurry and just want to test it out you can cheat and just pop this in applicationDidFinishLaunching delegate:
// Register for push notifications [[UIApplication sharedApplication] registerForRemoteNotificationTypes:(UIRemoteNotificationTypeBadge | UIRemoteNotificationTypeSound | UIRemoteNotificationTypeAlert)];
Then you probably want this to get the ID out into the console:
- (void)application:(UIApplication *)app didRegisterForRemoteNotificationsWithDeviceToken:(NSData *)devToken {
// Registration was successful so we'll
// set up our device token etc.
deviceToken = devToken;
NSLog(@"devToken=%@",deviceToken);
self.registered = YES;
}
- (void)application:(UIApplication *)app didFailToRegisterForRemoteNotificationsWithError:(NSError *)err {
// This is expected on the emulator so that's fine
NSLog(@"Error in registration. Error: %@", err);
}
Then you’ll be good to go! Run the app on the phone and the console will output the ID. Created an iPhone object and send a message. Job done.
Hey,
Great post. I’m struggling with one line though: self.registered = YES.
This throws a compile error, “request for member ‘registered’ is something not in a structure or union”
Any ideas most welcome!
Richard
Hi,
Is there any success in getting feedback from APNS for devices failed to receive the notification? I am successfully able to connect to the feedback server and I did a fread. But fread() always returns me blank
Thanks,
-Anish
@ Anish – I have never got any feedback on either live or sandbox. Not sure what’s going on there to be honest.
finally i got the feedback service working on my production environment. I get some unreadable (hex)characters as output from the feedback service. I convert those to a string. But the converted string doesn’t seem to be matching with the device token of the iPhone. Need to dig more into it.
-Anish
Ahhh wow – ace! I’ll connect to it later and dump the output from it. Remember that there are headers to each entry (but no footer) – could that be what you’re missing?
Hi,
what is “self.registered = YES” ?
it causes an error.
The callback methods never gets executed. Here is my code.
- (void)applicationDidFinishLaunching:(UIApplication *)application {
NSLog(@”Registering Remote Notications”);
[[UIApplication sharedApplication] registerForRemoteNotificationTypes:(UIRemoteNotificationTypeBadge | UIRemoteNotificationTypeSound | UIRemoteNotificationTypeAlert)];
// Override point for customization after app launch
[window makeKeyAndVisible];
}
// Delegation methods
- (void)application:(UIApplication *)app didRegisterForRemoteNotificationsWithDeviceToken:(NSData *)devToken {
const void *devTokenBytes = [devToken bytes];
// self.registered = YES;
NSLog(@”deviceToken: %@”, devToken);
// [self sendProviderDeviceToken:devTokenBytes]; // custom method
}
- (void)application:(UIApplication *)app didFailToRegisterForRemoteNotificationsWithError:(NSError *)err {
NSLog(@”Error in registration. Error: %@”, err);
}
And I did not get any error message from console. I successfully create my certificate and provisioning profile and btw I am testing on the phone.
self.registered is an NSString on the class and is in the .h file – the code assumes the reader and make that themselves.
You pasted your code, but I’m not sure you’re even calling it? The code has to be in the application instance for your app – otherwise it will not work.
You also have to make sure you set up your provisioning properly – this probably the most common error on the phone side. The app requires it’s own provisioning profile and development certificate from Apple – to even test.