Learning The Swizzle & Obj-C Runtime @ Evernote

Learning The Swizzle & Obj-C Runtime @ Evernote – CocoaCoder.org (Austin, TX) – Meetup

The April 19th meeting is being hosted by Evernote. To add to the fun, some of their engineers will present on such topics as method swizzling, just to name one. If you’ve never done swizzling, it’s a big RPG, so be careful how you use it. JC will walk us through that. And more.

Evernote is the latest major iOS house to locate in Austin. So if you’ve thought of making the big jump into full-time iOS work, this might be a good chance.

Advertisements

When Users Try To Upgrade An App Without a Connection

Store Kit is a great API because it lets developers create one app that can be enhanced through upgrades, buying tools, or whatever feature we want to offer the user to make the application more useful. In my case, all I want users to be able to do is upgrade their copy of Flush ’em! from the free edition for 99¢. The Flush ’em! upgrade allows the user to select from three bathroom choices.

But, there will come a time when a user will try to upgrade an app when she/he doesn’t have a network connection. And it’s fairly certain that such a user will flame the app page if the app doesn’t give the user the ability to go to Settings, turn on the network capability and then continue back to where the user left-off in the app to upgrade.

 

More…

When NSString Doesn’t Create A String With A String

If one goes to the NSString documentation, one quickly realizes that there is a very nice convenience method,

+ (id)stringWithString:(NSString *)aString

Parameters
aString

    The string from which to copy characters. This value must not be nil.

Important:
Raises an NSInvalidArgumentException if aString is nil.

Return Value
A string created by copying the characters from aString.

One would be forgiven for not noticing that little note that is supposed to catch your attention by having the title, Important. And it is important. Because, let’s say that you are trying to tell your iOS user how much an app feature upgrade cost,


NSString *titleString1 = [NSString stringWithString:@"Upgrade Flush'em for "];
NSString *titleString2 = [NSString stringWithString:[PFIAPManager sharedManager].upgradePrice];
NSString *titleString3 = [titleString1 stringByAppendingString:titleString2];
NSString *titleMessage = [titleString3 stringByAppendingString:@"?"];

  More…