app can't read preference unless Settings app is run first

[FlyingDiver]

This is very strange. I must be doing something fundamentally wrong.

My iPhone app has some preferences, with defaults stored in Settings.bundle/Root.plist. Looks like this:

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
	<key>Title</key>
	<string>iDSControl</string>
	<key>StringsTable</key>
	<string>Root</string>
	<key>PreferenceSpecifiers</key>
	<array>
		<dict>
			<key>Type</key>
			<string>PSTextFieldSpecifier</string>
			<key>Title</key>
			<string>D3 IP Address</string>
			<key>Key</key>
			<string>ip_address</string>
			<key>DefaultValue</key>
			<string>192.168.1.250</string>
			<key>IsSecure</key>
			<false/>
			<key>KeyboardType</key>
			<string>NumbersAndPunctuation</string>
			<key>AutocapitalizationType</key>
			<string>None</string>
			<key>AutocorrectionType</key>
			<string>No</string>
		</dict>
	</array>
</dict>
</plist>

The code to read the preference is:

#define kIPAddressKey	@"ip_address"
- (void)applicationDidFinishLaunching:(UIApplication *)application {    
	
	NSString *ipAddress = [[NSUserDefaults standardUserDefaults] stringForKey:kIPAddressKey];
	// do something with ipAddress here....
	
    [window makeKeyAndVisible];
}

When I first install this on the iPhone, the application crashes because ipAddress is NULL. If I switch to the Settings app and look at the page for this app, the default value from the Settings.bundle is there. When I switch back to the app, it runs fine. So apparently my app isn't getting the defaults until after Settings is run once. Any ideas on how to force it to update? I guess I could look for the null value, and throw an alert, but that's not very friendly. At best, it should use the default I defined. At worst, I'd like to know how to switch over to the Settings app.

Thanks!

joe

[FlyingDiver]

Now I'm thinking that the problem is related to my ViewController. The defaults setup (above) is done in the AppDelegate, but I have ViewControllers that are invoking methods that depend on the setup in the AppDelegate to be completed.

So it seems I need some way to tell the ViewControllers that the App setup is done, rather than them doing stuff in viewDidLoad. Do I need to get the controller list from the rootController and iterate through it, sending some sort of "startNow" message?

joe

[myersn024]

Unless they've changed something, you have to parse and synchronize the settings the first time the program runs; otherwise, you get the behavior that you're experiencing. There used to be an example app on the iPhone developer portal where Apple showed how to do this.

[FlyingDiver]

Originally Posted by myersn024

Unless they've changed something, you have to parse and synchronize the settings the first time the program runs; otherwise, you get the behavior that you're experiencing. There used to be an example app on the iPhone developer portal where Apple showed how to do this.

Interesting. None of the books or examples I saw ever pointed that out. I guess the Settings app does that for you, whenever it runs. Doesn't seem optimal to make me write parsing code that's already in Settings.

In any case, that fixed it. Thanks!

joe

[gonso75]

Originally Posted by FlyingDiver

Interesting. None of the books or examples I saw ever pointed that out. I guess the Settings app does that for you, whenever it runs. Doesn't seem optimal to make me write parsing code that's already in Settings.

In any case, that fixed it. Thanks!

joe

Hi

Im having the very same problem.
Can you illustrate how to "parse and synchronize the settings the first time the program runs"?

Thanks a lot!
Gonso

[menachi]

Well after spending more than a day on this issue i found a simple workaround that works perfectly.
I simply check if the appDefaults returns null, if it does i set the default value (in code) and then call the appDefaults synchronize afterwards.
That solves the issue.


if ([appDefaults stringForKey:@"my_key"] == nil){
[appDefaults setObject:@"my default value" forKey:@"my_key"];

}
NSString * val = [appDefaults stringForKey:@"my_key"];
[appDefaults synchronize];

good luck guys...

[shnaps]

Originally Posted by menachi

Well after spending more than a day on this issue i found a simple workaround that works perfectly.
I simply check if the appDefaults returns null, if it does i set the default value (in code) and then call the appDefaults synchronize afterwards.
That solves the issue.


if ([appDefaults stringForKey:@"my_key"] == nil){
[appDefaults setObject:@"my default value" forKey:@"my_key"];

}
NSString * val = [appDefaults stringForKey:@"my_key"];
[appDefaults synchronize];

good luck guys...

Have you figured out why the values are not read in first time??