I have this code snippet below. The purpose is to write the contents of an array to a plist file. When I run this I don´t get any errors and everything seems to be fine. The problem is that the file doesn´t appear on the desktop. I used writeToFile before in other projects without any problems. What is wrong with it? Greetings from Switzerland, Ronald Hofmann.
- (IBAction) doActionPlist: (NSButton *) sender
{
NSString *fileExt = #".plist";
NSArray *myResultArray = [NSArray arrayWithObjects:
#"Product Number Unlimited Desktop:",
#"4DDP120-UUS001-ANLKR-17C6B",
#"4DDP130-UUS001-ANQEI-1BC12",
#"4USE120-UUS001-80BY1-1EAB0",
#"4USE130-UUS001-6NTUE-11D64",
#"qA0iHnw4EIgOALgAAAQCmUtj",
#"qA0iHnw6EIgAALgAAPUBhByg",
#"4DDP11U00USN001",
#"4DDP13U12USN001",
#"4UCL00U00USN001",
#"4UCL00U00USN010",
#"4UCL11U00USN001",
#"4UCL11U00USN010",
#"4UCL12U11USN001",
#"4UCL12U11USN010",
#"4UCL13U12USN001",
#"4UCL13U12USN010",
#"4USE12U11USN002",
#"4USE13U12USN002",
#"4UWE13U12USN999",
nil];
NSString *thePath = [NSString stringWithFormat:#"/Users/ronny/Desktop/Testfile%#",fileExt] ;
[myResultArray writeToFile:thePath atomically:YES] ;
}
Unfortunately, it can be difficult to debug this call because it only returns YES or NO with no further information about why it succeeded or failed. The fact that it's not throwing any exceptions doesn't necessarily mean that nothing is going wrong; it just means that NSArray can't be bothered to tell you about it.
If you're really at wit's end, you might try converting your NSArray to NSData using NSPropertyListSerialization and then using writeToFile:options:error instead. If you do this, post the error message and someone should be able to offer better debugging advice.
Related
I am trying to check NSZombieEnabled is working in my code.
I've the following settings :
and I've the following code in didFinishLaunchingWithOptions
NSString *string = nil;
[string release];
string = #"abc";
but, there is no error generated. there is no notification from NSZombie as well. Should I do some more settings. Please help me, cause I've a lib that I've imported and there is a EXC_BAD_ACCESS with code 13 happening, and I am not able to get to the error cause.
The stack and the console looks like this
Your settings are correct, but your code does not create any zombies. A zombie is an object which has been freed, but is re-used. Something like this will create a zombie:
NSString* string = [NSString stringWithString:#"abc"];
[string release];
[string length];
In this example, the string is released, and then you attempt to use it by calling its length method.
In the case of your library, what does the stack look like when it gives you the EXC_BAD_ACCESS?
In my application, I want the user to be able to select a file/location to save data to. Thus, I'm using the following code:
NSSavePanel *newSavePanel = [NSSavePanel savePanel];
NSArray *newArray = [[NSArray alloc] initWithObjects:#"txt", nil]; //example file type
[newSavePanel setAllowedFileTypes:newArray];
NSInteger newInt;
newInt = [newSavePanel runModal];
My problem is that I want the save panel to alert the user and ask for confirmation to overwite if the file already exists. To do this, do I need to implement the delegate method panel:userEnteredFilename:confirmed: in which I place a [[NSFileManager defaultManager] fileExistsAtPath:] message, at which point I create an NSAlert, or is there a better way to go about doing this?
I haven't actually had time to test this, so if the behavior is already implemented in NSSavePanel, could someone let me know?
I may be wrong, but I think you get that behavior by default.
*edit - * yeah you get that out of the box, I used your code.
I'm creating a mac app that needs to create a file with the contents of another file, i'm creating it as follows:
NSString *p = #"/AfilethatEXISTS.plist";
NSString *user1 = #"~/Library/MyApp/myFile";
NSString *pT1 = [user1 stringByExpandingTildeInPath];
[[NSFileManager alloc] createFileAtPath:[NSURL URLWithString:pT1] contents:[NSData dataWithContentsOfFile:p] attributes:nil];
However returning no error, its not creating the file?
There are several things wrong with this code, but not enough context to tell you what is going wrong.
First, there should never be a file in / directly. That directory should be sacrosanct and many users will not be able to write to that directory without admin access.
Secondly, paths should be managed via the path manipulation APIs on NSString and NSURL.
Next, pT1 isn't really an URL and that is URLWithString: may be returning nil. Use fileURLWithPath: instead.
Finally, there isn't any error checking in that code and, thus, there is no way to tell how you might have discovered no error. What have you checked?
First off, you're creating the file manager instance incorrectly. To create a new instance, you need to both allocate and initialize it.
You're trying to pass an NSURL object, which won't be created correctly since the string you're using to create it with isn't a URL. But that doesn't matter anyway, because even if the NSURL was created, -createFileAtPath:contents:attributes: expects an NSString - just pass pT1 directly.
Better still, since you're basically just copying p to pT1, use the NSFileManager method for doing that. Not only is it conceptually a better fit, it also gives you a chance to examine a returned NSError object to see what (if anything) went wrong.
NSError *error;
NSFileManager *fm = [[[NSFileManager alloc] init] autorelease];
if (![fm copyFileAtPath:p toPath:pT1 error:&error]) {
// If copyFileAtPath:toPath:error: returned FALSE, an error occurred, and
// error will point to an NSError instance with more information
}
I have been searching for many days on how to save my apps data. I found some stuff but it was very complicated and badly explained. I need that when I completely close my apps all the data I entered in the text field are still there when I open my apps again. I tried a tutorial but this only let me save about 8 textfields and I need to save thousands I am starting Objective-C and Xcode so if somebody want to give me an answer please make it very precise.
Alright, what I'd suggest would be putting all the data from your text fields into an array and saving that to a file, then loading it when you re-open the app.
The first thing you need is a save file. This function will create one for you.
-(NSString*) saveFilePath{
NSString* path = [NSString stringWithFormat:#"%#%#",
[[NSBundle mainBundle] resourcePath],
#"myfilename.plist"];
return path;}
Now that that's done you need to create your saving array. Hopefully you have your thousands of textfields already fitted into an array of some sort. If not, this will be a painful process regardless of how you tackle it. But anyway... (Here, labelArray will be the array of all your text fields/labels/etc.)
NSMutableArray* myArray = [[NSMutableArray alloc]init];
int i = 0;
while(i < labelArray.count){
[myArray addObject: [labelArray objectAtIndex: i].text];
i ++;
}
[myArray writeToFile:[self saveFilePath] atomically:YES];
[myArray release];
And the loading code would be something along the lines of
NSMutableArray* myArray = [[NSMutableArray arrayWithContentsOfFile:[self saveFilePath]]retain];
Then you'd simply load the data back into your array of text fields.
Hope this helps.
It sounds like your application architecture may be unsound if you are planning on saving thousands of text fields' data in the fraction of a second you get while your app is closing. It would probably be better to save these as the user enters the data instead of waiting to save all the data at once.
To get the path you are going to write ( or read from! ) to, you do the following:
NSString *writableDBPath = [[NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex:0] stringByAppendingPathComponent:#"MyFile.extension"];
And then use a method like "writeToFile:automically:" of NSString or NSDictionary etc. to write to the path.
I am trying to output general data (source code) from a website, but it just sits there. Can't figure out if its the interface or the code. Would someone double-check for me?
#import "Lockerz_RedemptionViewController.h"
#implementation Lockerz_RedemptionViewController
-(IBAction)start: (id) sender {
while (1) {
NSMutableData *mydata = [[NSData alloc] initWithContentsOfURL:[NSURL URLWithString:#"http://ptzplace.lockerz.com/"]];
NSString *output = [[NSString alloc] initWithData:mydata encoding:NSASCIIStringEncoding];
NSLog(output);
}
}
The reason your NSLog doesn't work is it should use format strings.
Replace:
NSLog(output);
With:
NSLog(#"%#",output);
For more info see http://developer.apple.com/mac/library/documentation/Cocoa/Conceptual/Strings/Articles/FormatStrings.html
Why the while(1)? Are you intentionally trying to set up an infinite loop? You should just run this once, or maybe set up a periodic timer to reload it every few seconds, but certainly don't use an infinite loop for that... also it's been a while since I did anything with Cocoa networking, but you might want to look into NSURLRequest. You also may want to try NSData's dataWithContentsOfURL:options:error: and check the error parameter to better see what might be going wrong. Hope this helps you out.