Problem getting path to .plist using [[NSBundle mainBundle] pathForResource - iphone

I'm an Objective C noob, and I don't know enough to explain the following problem.
This code works:
NSString *plistPath = #"/Users/andrewf/MyApp/Resources/Plates.plist";
dicPlates = [[NSDictionary alloc] initWithContentsOfFile:plistPath];
My dictionary object is loaded with values as expected.
This code does not work:
NSString *plistPath = [[NSBundle mainBundle] pathForResource:#"Plates" ofType:#"plist"];
dicPlates = [[NSDictionary alloc] initWithContentsOfFile:plistPath];
plistPath comes back with a value of nil. This is the case irrespective of whether I include inDirectory:#"Resources" in the call or not. All the examples that I have found do not include inDirectory when trying to open a .plist file in the Resources directory.
I have confirmed that the file exists in the correct location and even recreated it to be sure.
This seems like such a simple problem, but I am mystified. Please assist.

I think you're confused as to where pathForResource: is looking.
This works:
NSString *plistPath = #"/Users/andrewf/MyApp/Resources/Plates.plist";
Notice that this path does not point to your application. It points to your project directory. Your plist is supposed to be at #/Users/andrewf/MyApp/build/Release/MyApp.app/Resources/Plist.plist" (for an iPhone app this would be different, more like #"/Users/andrewf/Library/Application Support/iPhone Simulator/User/Applicatons/(unique id)/MyApp.app/Resources/Plates.plist"), and it is inside the Resources folder of your app that pathForResource: is looking.
What this implies is that your resource is not in the "Copy Bundle Resources" phase of your build target. You need to drag it from the Groups and Files area to inside that phase.

I have found the problem!
The .plist file was included in the target correctly.
When the .plist was originally created, I named the file "plates.plist". Immediately after creating the file, I renamed it to "Plates.plist", and this is what I used henceforth.
Even though the file was named "Plates.plist" in my resources folder, in the target section and in the iPhone Simulator location mentioned above, the file was named "plates.plist". Curiously, the contents of the file was still updated correctly.
Now that I have changed the code to refer to "plates.plist", and renamed the file in the Resources folder to the same for good measure, everything works. I can only assume that this is a bug in the iPhone SDK.

Check that the plates.plist file has been added to the target in Xcode.
If the file is not added to the target it will not be inside the build product and NSBundle will not find it.

Related

Writing values to a .plist more than once?

I have an iPhone App in the works, and I have a settings page within the app. I use a .plist to store the settings that the user picks, and then I read the data from the .plist later. This is not the -Info.plist that comes with it when you create the project, it is another plist file. When I tested the settings after coding it, it worked. The setting was able to be read, and it was the correct setting that I used. However, I went back to the settings in the same app-session, and changed the same setting. When I went to the app to see if it read the new setting, it only used the old (first) one. I tried again, but it yielded the same result. I am only able to write the setting once, and I cannot 'rewrite' or 'overwrite' the same setting. I cannot figure out what is wrong for the life of me.
You can't overwrite or write to files in the app bundle itself. If you want to write to a file, you should first copy it to the app's Library or Documents directory, something like this:
NSString *docsDir = [NSSearchPathsForDirectoriesInDomains(NSDocumentsDirectory, NSUserDomainMask) objectAtIndex:0];
NSString *plistFile = #"myplist.plist";
NSString *plistInBundle = [[NSBundle mainBundle] pathForResource:plistFile ofType:nil];
NSString *plistInDocsDir = [docsDir stringByAppendingPathComponent:plistFile];
[[NSFileManager defaultManager] copyItemAtPath:plistInBundle toPath:plistInDocsDir error:NULL];
// now `plistInDocsDir` is (over)writeable
However, for storing preferences of your app, it's better practice to use the NSUserDefaults class:
[[NSUserDefaults standardUserDefaults] setObject:#"Some string" forKey:#"MySettingKey"];
and/or create a Preference Bundle for your app.

How to access local files within project

I want to add some static files (image, binary, etc...) to my app. I've placed them under a folder named Resources and have added it to my XCode project.
Next, I have those files added to the Copy Bundle Resources in the Build Phases tab in the project settings.
However, I can't seem to refer to them in the right way.
For instance, reading a binary file:
NSInputStream *is = [[NSInputStream alloc] initWithFileAtPath:#"data.bin"];
if(![is hasBytesAvailable]) NSLog(#"wrong");
This always fails & prints wrong
I tried a similar approach with NSData initWithContentsOfFile: but this wouldn't even execute. Another attempt was to use [NSBundle mainBundle] but this also didn't execute fully.
I'm new to iOS please help I can access my local files! Any help would be appreciated.
Thank you,
You need to ensure that you're accessing the file in the right place. Xcode places your resource files in the application's "application bundle" in the Resources directory. There are many ways to dig 'em out.
A common way is to get the pathname of a file in your bundle:
NSBundle *mainBundle = [NSBundle mainBundle];
NSString *myFile = [mainBundle pathForResource: #"data" ofType: #"bin"];
If you have other files in nonstandard places in your bundle, there are variations to pathForResource that let your specify a directory name.
If you want to see the actual location on your hard-drive that the simulator is using so you can inspect it, you can say:
NSLog(#"Main bundle path: %#", mainBundle);
NSLog(#"myFile path: %#", myFile);
Search for the "Bundle Programming Guide" in the Xcode documentation library to get started. :-)
Use NSBundle class for that. For Example:
NSString *path = [[NSBundle mainBundle] pathForResource:#"data" ofType:#"bin"];
NSInputStream *is = [[NSInputStream alloc] initWithFileAtPath:path];
...
Indeed calling [is open] is needed even though you "initialiseWithFileAtPath". I would think the initialisation would automatically open the file for you, but it doesn't.

How to get file path in iPhone app

I have a problem accessing my files in my app.
I am currently using
//Directly from TileMap example from WWDC2010
NSString *tileDirectory = [[[NSBundle mainBundle] resourcePath]
stringByAppendingPathComponent:#"Tiles"];
to access my tiles for my MKOverlay. This gives me this directory
/Users/xxxx/Library/Application Support/iPhone Simulator/4.2/Applications/9D62025C-C53B-472C-8309-xxxx/xxxx.app/Tiles
The x's is only for privacy reasons
I have my tiles in a folder called Tiles in the root of my application which is in Xcode in a group called Tiles which is in directly in the Resources group.
When I run my app, I get a simple error saying that it could not find my tiles at the generated directory (the one quote above) If I replace that piece of code and make it:
NSString *tileDirectory = #"/Users/xxxx/Documents/xxxx/Tiles";
Then my app works fine. This is obviously because it finds my tiles in its direct location on my Mac. This is fine for testing, but I need it to work on my iPhone/iPad.
This problem might be occurring due to:
The generated directory is incorrect.
The tile images aren't getting included in the builded .app file.
Either way, I have no clue of what to do to solve it.
How can I solve this problem?
[EDIT]
I changed that piece of code to:
NSString *tileDirectory = [[NSBundle mainBundle] resourcePath];
Now it works in simulator, because all files are in the apps root folder and I don't ask for it to enter another directory called "Tiles".
This runs with no error on the simulator, but when on my iPhone it gives the original error (just a different file path but also ending with /xxxx.app
How can I ensure a directory in my app file such as xxxx.app/Tiles - TileMap does this.
Since it is your files in your app bundle, I think you can use pathForResource:ofType: to get the full pathname of your file.
Here is an example:
NSString* filePath = [[NSBundle mainBundle] pathForResource:#"your_file_name"
ofType:#"the_file_extension"];
Remember that the "folders/groups" you make in xcode, those which are yellowish are not reflected as real folders in your iPhone app. They are just there to structure your XCode project. You can nest as many yellow group as you want and they still only serve the purpose of organizing code in XCode.
EDIT
Make a folder outside of XCode then drag it over, and select "Create folder references for any added folders" instead of "Create groups for any added folders" in the popup.
If your tiles are not in your bundle, either copied from the bundle or downloaded from the internet you can get the directory like this
NSString *documentdir = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) lastObject];
NSString *tileDirectory = [documentdir stringByAppendingPathComponent:#"xxxx/Tiles"];
NSLog(#"Tile Directory: %#", tileDirectory);
You need to use the URL for the link, such as this:
NSURL *path = [[NSBundle mainBundle] URLForResource:#"imagename" withExtension:#"jpg"];
It will give you a proper URL ref.
You need to add your tiles into your resource bundle. I mean add all those files to your project make sure to copy all files to project directory option checked.

Array does not load data from plist

I'm not sure what exactly is my problem since I have been using this method for a while now and never had this problem.
Basically, as the title says. This code loads data from a plist located in the "Resources" group
NSString *myFile = [[NSBundle mainBundle] pathForResource:#"myList" ofType:#"plist"];
myArray = [[NSArray alloc]initWithContentsOfFile:myFile];
NSLog(#"%#", myArray);
It displays (null). Anyone know why?
I have in the same ViewController another one setup and works just fine. This particular plist does not load however. And I've also even deleted the plist and just created a duplicate from the other one to make sure is not a structure issue.
I am doing this the wrong way? Should I use FileManager?
UPDATE -------------------------------------------------------------------------
Ok so, I can't believe what I am about to say. lol
I am using XCode 4, the way you edit plists in Xcode is different from Xcode 3.x. As in the earlier versions you get to choose the root of the plists to be w/e you want them to (Array, Dictionary, etc) My problem was that the plist I was trying to load into a NSArray was in fact structured as a dictionary. However I never saw this in Xcode, and I have no idea how to see this other than browsing the contents using TextEdit or some other text editor.
Pretty silly I must say. Does anyone know why XCode 4 won't show the root of the plist the way XCode 3.x does?
XCode 3.x: http://dl.dropbox.com/u/919254/XCode3.png
XCode 4: http://dl.dropbox.com/u/919254/Screen%20shot%202011-04-10%20at%202.30.35%20AM.png
Use a dictionary instead. I've had undefined behavior with NSArrays and property lists. e.g.
NSString *myFile = [[NSBundle mainBundle] pathForResource:#"myList" ofType:#"plist"];
NSMutableDictionary* myDict = [[NSMutableDictionary alloc]initWithContentsOfFile:myFile];
NSLog(#"%#", myDict);
I had a similar situation. Solving:
select *.plist in tree
call context menu
select "Open with external editor"
root will be visible - change "Class" to "Array"
save
What you have looks right. Check that the file is in the right directory, and has contents. Might want to NSLog myFile while your at it.

(IPHONE) Big confusion to read/write the same file from resource folder

i've read several thread for this question but unfortunatly not found the answer to my problem :(
i have a xml file in resource folder, and i need just to re-write the same file;
the app logic is:
display data loaded from file
add new data to the same file
for read a file my code is:
NSString *filePath = [[NSBundle mainBundle] pathForResource:#"myfile" ofType:#"xml"];
NSData *dataXml=[NSData dataWithContentsOfFile:filePath];
for re-write the same file:
NSString *myDataString = #"?xml version=""1.0"" encoding=""UTF-8""?";
NSString *path = [[NSBundle mainBundle] pathForResource:#"myfile" ofType:#"xml"];
BOOL ok=[myDataString writeToFile:path atomically:YES encoding:NSUnicodeStringEncoding error:nil];
For read works fine, but when i try to write, the file is not updated, but it was created another one in another folder, i've tested this in the simulator noting that an app is in a folder like this:
Users/user/Library/Application Support/iPhoneSimulator/Users/Applications/05279766-7B2C-4FC0-BFB0-D87A158A3337/
where there are 3 folder (Documents,tmp,Libary) and the bundle file .app (where there is my xml file)
My question are: is my logic wrong? in wich way are managed app folders in the device??
thanks in advance and sorry for the long thread!
You cannot write files into your application bundle; it's read only (on the device, at least; you may be able to do this in the Simulator).
What you should do is use your ~/Documents folder for the file. If it's not there, first read it from your bundle, then write it out to ~/Documents, and from then on, read it from there.