HowTo read random lines from plist ?

[J-E]

Hi ! I'm an absolute beginner in XCode and Objective-C, that allmost sounded like the title of the book I'm reading I'm trying to do a small app that read a random line from a text file, when pressing a button on the screen, and then display the result. After a lot of reading in different forums I did find a thread that explained that the best way to it, was to use "plist" instead of a plain textfile... The "jhaList.plist" file is an array, consisting a few lines (strings). Right now it consists of 5 lines:

Line 1
Line 2
Line 3
Line 4
Line 5

But when I get this to work, I want to have about 500 lines in it !

So this is my code so far:

The .h file:
------------

#import <UIKit/UIKit.h>

@interface jha_003ViewController : UIViewController {

	IBOutlet UILabel *randLine;	
}
NSString *fileContents;

@property (retain,nonatomic) IBOutlet UILabel *randLine;

-(IBAction)randomNumber:(id)sender;

@end

The .m file:
--------------

#import "jha_003ViewController.h"

@implementation jha_003ViewController
@synthesize randLine;

- (IBAction)randomNumber:(id)sender {
	
	fileContents = [[NSBundle mainBundle] pathForResource:@"jhaList" ofType:@"plist"];
	
	NSDictionary *jhaList = [[NSDictionary alloc] initWithContentsOfFile:fileContents];
	
	NSMutableArray *jhaArray = [jhaList valueForKey:@"jhaArray"];
	
	int randomNumber = arc4random() % [jhaArray count];
	jhaArray = [jhaArray objectAtIndex:randomNumber];
	for (NSString *randomNumber in jhaArray)
		randLine.text = (@"%@", randomNumber);
}

----------------------

But when running the app, it does display the "generate" button linked to "randomNumber" as expected, when pressing it, the app just quit and just jumps out ! It seems that I don't get any value back to the "randLine" which is connected to an UILabel. Can someone point me in the right direction ? As I said I'm a absolute beginner, so please give basic instructions

//J-E

[jNoxx]

Read the sticky about posting new posts.

http://www.iphonedevsdk.com/forum/ip...new-topic.html

With other words, use CODE tags. otherwise no one is interested in helping u, no personal offense.

[J-E]

Thanks jNoxx, for pointing that out ! I'm sorry, but I did not know !
I added [ code] and [ /code] before and after the code. It didn't do any difference, the smileys did show anyway ! So I removed since it didn't work ! Can you give me an example, because it's really anoying to have these smileys in the code ?

Thanks for your patience !
J-E

[Meredi86]

when you post there is a # symbol at the top of the text box

any text that is within the two tags that appear when you hit the # symbol will be up as code not just text

i cant remember jnoxx's words but i think he got a little muddled when posting that, you need to get rid of the spaces between the [ and c or /. I am not entirely certain about the caps - i always do it manually like this:
[ CODE] [ /CODE] but with NO spaces.

[jNoxx]

Yea, sorry, that's what I said in my post. It says, use the # on top of a post (not the quick post, then press "Go Advanced", and second. I also said, u have to delete the spaces between them, because otherwise i wouldve got me a clean code box, so then u wouldn't understand.
So try fixing it! good luck

[Meredi86]

ah sorry jnoxx, though you said (leave spaces) i could see how some people around here may find that confusing and not be able to debug that message.

[J-E]

Thanks Meredi86 ! Now it looks a lot better !

[jNoxx]

Originally Posted by Meredi86

ah sorry jnoxx, though you said (leave spaces) i could see how some people around here may find that confusing and not be able to debug that message.

Changing it, thanks for the pointer

[cityofangels]

is there a solution for this?

[kapps11]

plists can be read as arrays, and then its a very simple matter of picking a random object from that array

[Duncan C]

Originally Posted by J-E

Hi ! I'm an absolute beginner in XCode and Objective-C, that allmost sounded like the title of the book I'm reading I'm trying to do a small app that read a random line from a text file, when pressing a button on the screen, and then display the result. After a lot of reading in different forums I did find a thread that explained that the best way to it, was to use "plist" instead of a plain textfile... The "jhaList.plist" file is an array, consisting a few lines (strings). Right now it consists of 5 lines:

Line 1
Line 2
Line 3
Line 4
Line 5

But when I get this to work, I want to have about 500 lines in it !

So this is my code so far:

The .h file:
------------

#import <UIKit/UIKit.h>

@interface jha_003ViewController : UIViewController {

	IBOutlet UILabel *randLine;	
}
NSString *fileContents;

@property (retain,nonatomic) IBOutlet UILabel *randLine;

-(IBAction)randomNumber:(id)sender;

@end

The .m file:
--------------

#import "jha_003ViewController.h"

@implementation jha_003ViewController
@synthesize randLine;

- (IBAction)randomNumber:(id)sender {
	
	fileContents = [[NSBundle mainBundle] pathForResource:@"jhaList" ofType:@"plist"];
	
	NSDictionary *jhaList = [[NSDictionary alloc] initWithContentsOfFile:fileContents];
	
	NSMutableArray *jhaArray = [jhaList valueForKey:@"jhaArray"];
	
	int randomNumber = arc4random() % [jhaArray count];
	jhaArray = [jhaArray objectAtIndex:randomNumber];
	for (NSString *randomNumber in jhaArray)
		randLine.text = (@"%@", randomNumber);
}

----------------------

But when running the app, it does display the "generate" button linked to "randomNumber" as expected, when pressing it, the app just quit and just jumps out ! It seems that I don't get any value back to the "randLine" which is connected to an UILabel. Can someone point me in the right direction ? As I said I'm a absolute beginner, so please give basic instructions

//J-E

You say your plist contains an array, but the code you posted reads the file as a dictionary, then reads an array from that dictionary. How are you creating this plist file?

And you say it just quits and jumps out. You need to run the program in the debugger and step through it line by line, checking the values of all your variables until you find the line that is crashing.

If I had to guess, I would guess that you are not reading your array properly, so it has zero elements. Then when you try to do the "arc4random() % [jhaArray count]" statement, you're crashing on a divide-by-zero error (the modulo operator is a remainder operator, and does a divide to find the answer.)