Can't understand, why does this line of the code return (null)?
// Get path of data.plist file to be created
plistPath = [[NSBundle mainBundle] pathForResource:#"data" ofType:#"plist"];
I need to create new plist but can't understand, does the empty file should be created before to get the path to it.. Any ideas?
PS I had only h,m and no plist files in my project now.
You don't create new files in your bundle after deployment. The bundle contains all the resources and files that ship with your app.
Instead, you create new files in your app's Documents folder. To get the documents folder path, you can use a method like this (as included in some of the app template projects):
- (NSString *)applicationDocumentsDirectory {
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *basePath = ([paths count] > 0) ? [paths objectAtIndex:0] : nil;
return basePath;
}
Then you simply append the file name you want to use.
NSString *path = [self applicationDocumentsDirectory];
path = [path stringByAppendingPathComponent:#"data.plist"];
You might also want to have some additional folders in your Documents folder for organizational purposes. You can use NSFileManager to do that.
Yes, your guess was right - you would need to create a file first. Here is what the class reference documentation had to say about the method's return value
"Return Value
The full pathname for the resource file or nil if the file could not be located."
You could do something like:
if ( [ [NSBundle mainBundle] pathForResource:#"data" ofType:#"plist"] )
plistPath = [[NSBundle mainBundle] pathForResource:#"data" ofType:#"plist"];
else
// Create new file here
Also, you could leave out the type extenxion in the method call above if you are searching for a unique file name.
Source: http://developer.apple.com/library/mac/#documentation/Cocoa/Reference/Foundation/Classes/NSBundle_Class/Reference/Reference.html
Related
What is the best way to get property list?
1 - From main bundle, i.e.:
NSString *path = [[NSBundle mainBundle] pathForResource:#"recipes" ofType:#"plist"];
2 - Or get path from Documents directory, i.e.:
// Data.plist code - get path from root direcory
NSArray *paths = NSSearchPathForDirectoriesInDomains (NSDocumentDirectory, NSUserDomainMask, YES);
// get documents path
NSString *documentsPath = [paths objectAtIndex:0];
// get the path to our plist file.
NSString *plistPath = [documentsPath
stringByAppendingPathComponent:#"Data.plist"];
// check to see if Data.plist exists in documents
if (![[NSFileManager defaultManager] fileExistsAtPath:plistPath]) {
// if not in documents, get property list from main bundle
plistPath = [[NSBundle mainBundle] pathForResource:#"Data" ofType:#"plist"];
}
What and why?
And if both are correct then why do we not use 1st one with just one line of code?
Simple rule:
If the property list file is read-only put it in the bundle.
If the property list file is going to be mutated put it in the document directory.
I have created a custom property list file. The file is stored in the application document.
While user login is successful the login information is stored in the plist, and it is working fine.
The plist content are cleared while log out, this also works fine.
When i am still login i killed the application. When the app opens the plist data i cleared.
code used to save to file:
NSArray *paths = NSSearchPathForDirectoriesInDomains (NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsPath = [paths objectAtIndex:0];
NSString *plistPath = [documentsPath stringByAppendingPathComponent:#"xxxxPlist.plist"];
if (![[NSFileManager defaultManager] fileExistsAtPath:plistPath])
{
plistPath = [[NSBundle mainBundle] pathForResource:#"xxxxPlist" ofType:#"plist"];
}
dict=[[self cleanDictionary:[dict mutableCopy]] mutableCopy];
NSDictionary *plistDict=[[NSDictionary alloc] initWithObjectsAndKeys:dict,#"login_data", nil];
NSError *error = nil;
NSData *plistData = [NSPropertyListSerialization dataWithPropertyList:plistDict format:NSPropertyListXMLFormat_v1_0 options:NSPropertyListImmutable error:&error];
if(plistData)
{
[plistData writeToFile:plistPath atomically:YES];
}
else
{
//error here
NSLog(#"%# ",error);
}
code used to fetch data
NSArray *paths = NSSearchPathForDirectoriesInDomains (NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsPath = [paths objectAtIndex:0];
NSString *plistPath = [documentsPath stringByAppendingPathComponent:#"xxxx.plist"];
if (![[NSFileManager defaultManager] fileExistsAtPath:plistPath])
{
plistPath = [[NSBundle mainBundle] pathForResource:#"xxxxPlist" ofType:#"plist"];
}
NSDictionary *dict = [[NSDictionary alloc] initWithContentsOfFile:plistPath];
return [dict objectForKey:#"login_data"];
I there any way out to persist the data?
There are several things that may be causing problems
When saving to file
1) My understanding is that you specifically want to save to /Documents folder specifically to ensure your file persists
2) So you correctly build following path
"/Documents/xxxxPlist.plist"
3) But then why do you check if a file already exists at that location?
if (![[NSFileManager defaultManager] fileExistsAtPath:plistPath])
{
plistPath = [[NSBundle mainBundle] pathForResource:#"xxxxPlist" ofType:#"plist"];
}
You just have to write to the path when you are ready.
If there is an old file at this location it will be overwritten.
And my understanding is this is the wanted behaviour, because you've already read that file and the data is in that dictionary "dict".
4) Also, by asking NSBundle to give you path for your file name
"xxxxPlist.plist"
there is a risk that it will just give you back some other path with file named the same (not in /Documents) if such file happens to exist. For example if you happened to write to say, /Cache folder earlier (with different code), your app will keep getting the /Cache path and keep reading/writong there (not in /Documents). And with the existing code you would have gotten nil here for path on the very first run, so not sure how he file got created in the first place.
5) Then I am not sure what exactly does this line
dict=[[self cleanDictionary:[dict mutableCopy]] mutableCopy];
Why first make a mutable copy, then presumably get immutable copy back and get a mutable one of it. Can't -cleanDictionary: just return the same mutable copy it was passed?
When reading from file
1) Not sure why you're searching for a different file first?
"/Documents/xxxx.plist" not "/Documents/xxxxPlist.plist"
Also what happens if "xxxx.plist" exists, then you'll never get to "xxxxPlist.plist" that you are writing in the other section.
2) Then, yes, you have to check if a file exists at certain path before you try to read it. But, in your case, if it does not exist, you don't ask NSBundle for another location, because you need your specific file in /Documents, and you don't know what you'll get from NSBundle, if your file is not where it should be.
So if there is no "xxxxPlist.plist" file, it's just your first run of the app and you will be creating your initial dict.
My Xcode app creates a document and resource path. Please see the console output below when I print out these two path variables:
However, when I try to find this folder in Finder, I'm told the folder doesn't exist.
Why?!
The code for getting the two paths are below:
// Get the path to the resource directory.
NSString* resourcePath= [[NSBundle mainBundle] resourcePath];
std::string *resourcePathCPP = new std::string([resourcePath UTF8String]);
// Get the path to the Documents direcotory
NSArray* paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString* documentsPath = ([paths count] > 0) ? [paths objectAtIndex:0] : nil;
std::string *documentsPathCPP = new std::string([documentsPath UTF8String]);
Thanks!
That should be on your iPhone/iPad's file system, not on your Mac. Otherwise Go to folder ... Is the right way to check a directory.
Hello everyone i have the following code :
NSString* issuePath =[[self contentURL] URLByAppendingPathComponent:#"magazine"].path;
I have a file called a.plist in the above directory. I have to read the a.plist file contents. How to do that. Before the file was local and I was accessing it as follows
NSString *path = [[NSBundle mainBundle] pathForResource:#"a" ofType:#"plist"];
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:0];
NSString *path = [documentsDirectory stringByAppendingPathComponent:#"a.plist"];
NSMutableDictionary *plistContents = [[NSMutableDictionary alloc] initWithContentsOfFile:path];
Refer this file handler utility which provides API's to interact with most of your file related operations.
It exposed API for below features,
Check if the file, or directory, exists in the given path
Create a folder in a given path
Verify if a folder exists at a given path
Get the size of a file
Check if a file with that name exists in the folder
Check if this folder has more subfolder or if it's the last folder
File Handler Utility Class link
You can simply use the following method.
NSString *path = [[NSBundle mainBundle] pathForResource:#"a" ofType:#"plist"];
NSDictionary *dict = [[NSDictionary alloc] initWithContentsOfFile:path];
I have a plist file I just created of strings; it looks like this:
This is the code I'm using to create the path to the file:
NSError *error;
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES); // Create a list of paths
NSString *documentsDirectory = [paths objectAtIndex:0]; // Get a path to your documents directory from the list
NSString *path = [documentsDirectory stringByAppendingPathComponent:#"NailServices.plist"]; // Create a full file path
NSFileManager *fileManager = [NSFileManager defaultManager];
if (![fileManager fileExistsAtPath: path]) { // Check if file exists
// Get a path to the plist created before in bundle directory (by Xcode)
NSString *bundle = [[NSBundle mainBundle] pathForResource: #"NailServices" ofType: #"plist"];
[fileManager copyItemAtPath:bundle toPath: path error:&error]; // Copy this plist to your documents directory
}
This is the code I'm using to examine the data (to make sure this is working)... I'm getting a (null) back from the NSLog statement)
//Load Dictionary with wood name cross refference values for image name
NSString *plistDataPath = [[NSBundle mainBundle] pathForResource:#"NailServices" ofType:#"plist"];
NSDictionary *NailServicesDictionary = [[NSDictionary alloc] initWithContentsOfFile:plistDataPath];
NSLog(#"\nnailServicesDict: %#", NailServicesDictionary);
This is my first attempt at creating/using a "strings" plist file; I have read everything I could find on Google and SO without finding an example of a plain ol' strings file. What else do I have to do to be able to get to this plist data?
Your problem is that you are creating an NSDictionary while your plist is an NSArray. Thus, it will return nil when you try to create it as a dictionary because no dictionary exists.
You need to change:
NSDictionary *NailServicesDictionary = [[NSDictionary alloc] initWithContentsOfFile:plistDataPath];
to
NSArray *NailServicesArray = [[NSArray alloc] initWithContentsOfFile:plistDataPath];
As a commenter posted, plist files can either have an NSArray or an NSDictionary as their root. Your example plist has an NSArray as its root, so you'll want to alloc and init an NSArray, not an NSDictionary. If your plist is stored in the app bundle when you build the app in Xcode and you don't need to modify it at runtime, then it's unnecessary to copy it to the NSDocumentsDirectory. Also, I'd recommend using [paths lastObject]; rather than [paths objectAtIndex:0];, which can throw an exception if the paths array is empty.