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Finish off UIAlertView post

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Wesley Moore 2011-12-11 17:23:08 +11:00
parent 468e89693a
commit f79cbb3b56
1 changed files with 10 additions and 11 deletions
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21
content/technical/2011/12/fun-with-objc-setassociatedobject-and-uialertview.html
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@ -1,10 +1,9 @@
When it comes time to present errors or other messages in iOS
with [UIAlertView] it becomes immediately obvious that a more
convenient interface would involve the use of blocks. A [search on
GitHub][github-search] shows just about every iOS developer has had a
crack at it.
When it comes time to present errors or other messages in iOS with
[UIAlertView] it is immediately obvious that a more convenient interface
would involve the use of blocks. A [search on GitHub][github-search]
shows just about every iOS developer has had the same thought and had a crack at it.
[UIAlertView]: TODO
[UIAlertView]: http://developer.apple.com/library/ios/#documentation/uikit/reference/UIAlertView_Class/UIAlertView/UIAlertView.html
[github-search]: https://github.com/search?type=Repositories&language=&q=uialertview&repo=&langOverride=&x=14&y=17&start_value=1
After reviewing the better options (I.e. those that actually had a
@ -25,19 +24,19 @@ blocks based wrapper with the UIAlertView.
[set-object]: http://developer.apple.com/library/ios/#documentation/Cocoa/Conceptual/ObjectiveC/Chapters/ocAssociativeReferences.html
In the `init` method:
In the `init` method the wrapper instance is associated with its UIAlertView:
objc_setAssociatedObject(alertView, _cmd, self, OBJC_ASSOCIATION_RETAIN);
Note that I'm using the implicit second argument to the method, its
selector, `_cmd` as the key for the associated object. This was
suggested in a [tweet by Bill Bummager][bbum]. TODO
suggested in a [tweet by Bill Bumgarner][bbum].
[bbum]: http://twitter.com/bbum/status/3609098005
Then in `alertView:didDismissWithButtonIndex:`, the association is
removed, `dealloc` of the wrapper called and the `UIAlertView` also
released.
Then in `alertView:didDismissWithButtonIndex:`, the association
is removed, `dealloc` of the wrapper called as a result and the
`UIAlertView` also released.
SEL key = @selector(initWithTitle:message:);
objc_setAssociatedObject(self.alertView, key, nil, OBJC_ASSOCIATION_RETAIN);