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.
Related
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.
I processed drag operation from browser view to custom view.It work well in snow lepoard,but not in Mountain Lion with sandbox.
in browser view:
NSMutableArray* urls = [[[NSMutableArray alloc] init] autorelease];
..............put some NSUrl to urls array....................
[pasteboard writeObjects:[NSArray arrayWithArray:urls]];
in my receive custom view:
NSArray* pasteboardItems = [pasteboard readObjectsForClasses:[NSArray arrayWithObject:[NSString class]] options:nil];
NSArray* pasteboardItems2 = [pasteboard readObjectsForClasses:[NSArray arrayWithObject:[NSURL class]] options:nil];
NSArray* pasteboardItems3 = [pasteboard readObjectsForClasses:[NSArray arrayWithObject:[NSImage class]] options:nil];
NSLog(#"%#",pasteboardItems);
NSLog(#"%#",pasteboardItems2);
NSLog(#"%#",pasteboardItems3);
my log is:
2012-08-09 18:33:43.886 iCollage[6885:303] __CFPasteboardIssueSandboxExtensionForPath: error for [/Users/xxxx/Library/Containers/xxxxxxxxxxxx/Data/Downloads/1343902069.jpg]
2012-08-09 18:33:44.546 iCollage[6885:303] ( "file://localhost/Users/xxx/Library/Containers/xxxxxxxx/Data/Downloads/1343902069.jpg")
2012-08-09 18:33:44.547 iCollage[6885:303] ( "file://localhost/Users/xxxxx/Library/Containers/xxxxxx/Data/Downloads/1343902069.jpg")
2012-08-09 18:33:44.547 iCollage[6885:303] ()
my question is:
1.how to fix this error __CFPasteboardIssueSandboxExtensionForPath;I refer the docs and found nothing about that.I am ensuer that i have the permission to access the file!google says, may be "startAccessingSecurityScopedResource" will help me, then i try and failed
2.why pasteboardItems2 have value?i write to pasteboard only url but not string.It disgusted me that I can get the url both from NSString type and NSUrl type! (I try drag a file from iFinder, the url will only exist in pasteboardItems but not pasteboardItems2).Anybody know why? I think the first problem will auto fixed when some one help me fix this problem.
I believe Apple answer question 1:
Important: Although you can support dragging file paths, in general,
you should avoid doing so unless you are certain that the destination
app will never be run in an app sandbox. If you use an NSString, OS X
has no way to know whether that string should be interpreted as a
path; thus, OS X does not expand the destination app’s sandbox to
allow access to the file or directory at that location. Instead, use
an NSURL, a bookmark, or a filename pasteboard type.
WRT to question 2, it looks like you have pasted URLs so reading NSURL objects would seem to be correct. However I think you should implement the dragging using the following code (also from the link above):
- (BOOL)performDragOperation:(id <NSDraggingInfo>)sender
{
NSPasteboard *pboard = [sender draggingPasteboard];
if ( [[pboard types] containsObject:NSFilenamesPboardType] ) {
NSArray *files = [pboard propertyListForType:NSFilenamesPboardType];
int numberOfFiles = [files count];
// Perform operation using the list of files
}
return YES;
}
You need to generate security-scoped URL bookmark data on the sender side, and turn that data back into a URL on the receiver side. There's some other stuff you have to do after that when you want to actually access the URL; the documentation elaborates.
The receiving application, when running in a sandbox, will not be able to handle bare paths. This is a core part of being sandboxed; you are not allowed to use bare paths or their corresponding URLs to access files that aren't in your sandbox container and haven't been explicitly handed to you by the user.
Your pasteboardItems read object of NSString type, but you dragged a file(with jpg extension), you should register for NSString type in your init method:
[self registerForDraggedTypes:[NSArray arrayWithObject:NSPasteboardTypeString]];
You need to have Document Types defined in your application so that the sandboxing mechanism knows your application should be opening files with those extensions. You can do this by clicking the project on the left in Xcode, and in the Info tab, under Document Types add a new document type for each extension.
You just need to fill in the name and extensions field.
Also if you want to persist your permission to access the files dragged onto your application, you can use this class to wrap up all that logic. https://github.com/leighmcculloch/AppSandboxFileAccess
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.
My application allows the user to rename documents that are currently open. This is trivial, and works fine, with one really annoying bug I can't figure out. When a file is renamed, AppKit (kindly) warns the user the next time they try to save the document. The user says "OK" and everything continues as normal. This makes sense when something external to the application changed the document, but not when it was actually done by the document itself.
The code goes something like this:
-(void)renameDocumentTo:(NSString *)newName {
NSURL *newURL = [[[self fileURL] URLByDeletingLastPathComponent]
URLByAppendingPathComponent:newName];
NSFileManager *fileManager = [NSFileManager defaultManager];
[fileManager moveItemAtURL:[self fileURL] toURL:newURL];
NSDictionary *attrs = [fileManager attributesForItemAtPath:[newURL path] error:NULL];
[self setFileURL:newURL];
[self setFileModificationDate:[attrs fileModificationDate]];
}
One would think that expressly setting the new URL and modification date on the document would be enough, but sadly it's not. Cocoa still generates the warning.
I've tried changing the order (setting the new URL on the document, THEN renaming the file) but this doesn't help.
I've also tried a fix suggested by a user on an old post over at CocoaDev:
[self performSelector:#selector(_resetMoveAndRenameSensing)];
Even this does not stop the warning however, and I'm guessing there has to be a proper way to do this using the documented API. How does Xcode handle things when a user clicks a file on the project tree and renames it to something else. It doesn't warn the user about the rename, since the user actually performed the rename.
What do I need to do?
There isn't much on this in the main docs. Instead, have a look at the 10.5 release notes: http://developer.apple.com/library/mac/#releasenotes/Cocoa/AppKitOlderNotes.html%23X10_5Notes under the heading "NSDocument Checking for Modified Files At Saving Time"
(In the case of Xcode, it has a long history and I wouldn't be surprised if if doesn't use NSDocument for files within the project)
It is worth noting that moving a file does not change its modification date, so calling -setFileModificationDate: is unlikely to have any effect.
So one possibility could be to bypass NSDocument's usual warning like so:
- (void)saveDocument:(id)sender;
{
if (wasRenamed)
{
[self saveToURL:[self fileURL] ofType:[self fileType] forSaveOperation:NSSaveOperation delegate:nil didSaveSelector:nil contextInfo:NULL];
wasRenamed = NO;
}
else
{
[super saveDocument:sender];
}
}
Ideally you also need to check for the possibility of:
Ask app to rename the doc
Renamed file is then modified/moved by another app
User goes to save the doc
At that point you want the usual warning sheet to come up. Could probably be accomplished by something like:
- (void)renameDocumentTo:(NSString *)newName
{
// Do the rename
[self setFileURL:newURL];
wasRenamed = YES; // MUST happen after -setFileURL:
}
- (void)setFileURL:(NSURL *)absoluteURL;
{
if (![absoluteURL isEqual:[self fileURL]]) wasRenamed = NO;
[super setFileURL:absoluteURL];
}
- (void)setFileModificationDate:(NSDate *)modificationDate;
{
if (![modificationDate isEqualToDate:[self fileModificationDate]]) wasRenamed = NO;
[super setFileModificationDate:modificationDate];
}
Otherwise, your only other choice I can see is to call one of the standard save/write methods with some custom parameters that prompt your document subclass to move the current doc rather than actually save it. Would be trickier I think. Perhaps define your own NSSaveOperationType?
With this technique the doc system should understand that the rename was part of a save-like operation, but it would need quite a bit of experimentation to be sure.
Much inspired from #Mike's answer, I got the "moved to" message not to show up anymore by re-routing NSSaveOperation to NSSaveAsOperation. In my NSDocument subclass:
I overload saveDocumentWithDelegate:didSaveSelector:contextInfo: to determine the save URL and document type (assigning those to self); if the old fileURL exists, I move that to the new location
Inside saveDocumentWithDelegate:didSaveSelector:contextInfo: I redirect the call to [self saveToURL:self.fileURL ofType:self.fileType forSaveOperation:NSSaveAsOperation completionHandler: ...] instead of [super saveDocumentWithDelegate:didSaveSelector:contextInfo:]
This works for me.
Isn't it possible to programmatically answer the question for the user?
Or you can save immediately after renaming, this way a user gets every answer in one go.
I see that this problem is up and running for some time, so telling you to read the reference won't do any good i guess..
Hope i helped a little bit although it doesn't fix your problem directly
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.