Database Reference
In-Depth Information
completion: nil )
}
Tapping on Rate now brings up an alert view with a single text field, a cancel button
and a save button. Tapping the save button calls the method updateRating , which…
Whoops, you haven't defined it yet. Appease Xcode by implementing it below:
func updateRating(numericString: String ) {
currentBowtie . rating = (numericString as NSString) . doubleValue
var error: NSError ?
if ! managedContext . save (&error) {
println ( "Could not save \(error) , \(error!. userInfo ) " )
}
populate ( currentBowtie )
}
You convert the text from the alert view's text field into a double and use it to
update the current bow ties rating property.
Finally, you commit your changes as usual by saving the managed context and
refresh the UI to see your changes in real time.
Try it out. Build and run the app and tap Rate :
Enter any decimal number from 0 to 5 and tap Save . As you would expect, the
rating label updates to the new value you entered.
Now tap Rate one more time. Remember the timeless elegance of a red bow tie?
Let's say you like it so much that you decide to rate it a 6 out of 5. Tap Save to
refresh the user interface:
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