If you scroll down to the section 'Writing to Files and URLs' at this link, would the path varaible have to be a file on disk? Is it possible to write to a file in the bundle or must it always be deployed first?
You can write files to the application bundle as much as you'd like. Just get the path of the file through NSBundle's pathForResource:ofType: method and you can write to that file. If you want just the directory of the bundle, use resourcePath.
You don't want to do this, though. There are various reasons, but you'll break code signing, which is a big one. You should use the established conventions instead (such as writing to Library:Application Support:Your App).
EDIT: For a (possibly) more convincing reason of not to do this... When I was first learning Cocoa programming, I saved to the bundle because I didn't want to bother with the Library. It got really annoying, though, because every time you make a change to your program, you lose all of your saved data/settings for that program (assuming you're not using NSUserDefaults for preferences). I kept having to move it over from the old version to the new one. By using the Library, you don't have to worry about this.
The bundle is on disk; it's just the ".app" directory. You should not write to files in this directory, however. While currently possible on Mac, it will break code signing. On iPhone, you already can't write into your own bundle, and we should expect to see this limitation in the future on Mac. You should write your application files into various directories under ~/Library or ~/Documents as appropriate. See the File System Programming Guide for guidance.
Related
I have developed a simple app for Mac which uses a browser window to display some content. Now the assets (images etc.) are visible to anyone who receives the app and discloses the content in finder using 'show package content'.
Is there a way to prevent this? Can I hide it or encapsulate it somehow using code or some XCode function?
A trivial way would be to change the extension on your files so the system doesn't recognize them as images. You'd then have to load the images as data and convert them to images in code, which would be a bit of a pain.
A more rigorous solution would be to encrypt the images in your app bundle, then write a utility function that loads and decrypts images.
Here's another option.
You can zip all the assets. Use whatever is easiest e.g. pkzip or gzip or even just tar it all. Then you hide a lot of info and, if you want to go the extra step, it is easy to encrypt the zipped file and there are lots of libraries around to include in your project and use to unzip it with.
It should be easy to read assets directly from the zipped file, but if you need them individually you could e.g. put a single file / resource inside a zip or you could unzip it. You could even unzip to temporary space and remove it all when the app quits if you have really sensitive stuff that is too big to fit in memory.
** EDIT **
Java works this way right. A jar file is just a renamed zip and it often contains all of the resources the app needs, and it seems to be working there. So if that is a guide performance should not be too bad.
I'm trying to get a Cocoa development environment working in Emacs, and I'm 80% of the way there. The one feature I miss is Xcode's "Open Quickly", which basically performs a fuzzy match of the string you type against the filenames referenced in the Xcode workspace and the symbols defined in those files.
My problem is that our project is huge: if I generate a TAGS file using etags for the .h and .m files in our project's sub-directories, the result is over a gig in size and Emacs complains "TAGS file is large. Really open?", and if I say yes, then Emacs hangs and becomes essentially unusable. Of course, this is before I've even considered indexing tags for system libraries. I've also tried projectile, but unfortunately it's similarly unusable on a project of my size (on the order of a full minute to find a match).
It occurs to me that all the indexing information I really want is in the Xcode projects themselves, so if I had an Emacs package that could parse them and traverse their dependencies, that might be a start, but I'm not aware of any such package.
Any suggestions/solutions in this respect?
I've never found a single function quite as convenient as Xcode's "Open Quickly", but these days I use
helm-projectile-git-grep when I want to match on strings I know to be in the filenames, and
helm-git-grep for quick searches through the contents of the files themselves.
I've found that this gets me really close to what I wanted in my original question.
I know i can use 7z or winrar but i want to learn this for myself.
How would i implement a self extracting archive? I can use C# or C++ but let me run down the problem.
When i open the exe i need some kind of GUI asking where to extract the files. Once the user says ok I should obviously extract them. I implemented a simple example in C# winforms already BUT my problem is HOW do i get the filenames and binary of the files into an exe?
One upon a time i ask Is it safe to add extra data to end of exe? and the answer suggested if i just add data to the end of the exe it may be picked up by a virus scanner. Now its pretty easy to write the length of the archive as the last 4bytes and just append the data to my generic exe and i do believe my process can read my own exe so this could work. But it feels hacky and i rather not have people accuse me of writing virus just because i am using this technique. Whats the proper way to implement this?
Note: I checked the self-extracting tag and many of the question is how to manipulate self extracting and not how to implement. Except this one which is asking something else Self-extracting self-checking executable
-edit- I made two self extracting with 7z and compared them. It looks like... well it IS the 7z.sfx file but with a regular 7z archive appended. So... there is nothing wrong with doing this? Is there a better way? I'm targeting windows and can use the C# compiler to help but i don't know how much extra work or how difficult it may be programmatically and maybe adding data to end of exe isnt bad?
It is possible. I used the following technique once, when we needed to distribute updates for the application, but the computers were configured so that the end user had no permissions to change application files. The update was supposed to log on to administrator account and update required files (so we came across identical problem: how to distribute many files as a single executable).
The solution were file resources in C#. All you need to do is:
Create a resource file in your C# project (file ending with .resx).
Add new resource of type "file". You can easily add existing files as byte[] resources.
In program you can simply extract resource as file:
System.IO.FileStream file = new System.IO.FileStream("C:\\PathToFile",
System.IO.FileMode.OpenOrCreate);
System.IO.BinaryWriter writer = new System.IO.BinaryWriter(file);
writer.Write(UpdateApplication.Data.DataValue, 0, UpdateApplication.Data.DataValue.Length);
(Here UpdateApplication.Data denotes binary resource).
Our solution lacked compression, but I believe this is easily achieved with libraries such as C#ZipLib.
I hope this solution is virus-scanner-safe, as this method creates complete, valid executable file.
I'm very much a noob/hobbyist programmer, putting together a few simple Mac apps.
I'm confused about resource files.
I have some .png images sitting in a folder in my (XCode 4.4) project.
I also have a .plist (containing a dictionary) sitting in my Supporting Files folder.
To access the .plist, I've added a few lines of code to dig into the Bundle and get the file I'm after (pretty standard, I believe).
To use the .png files, I simply refer to them by name, and when I run from within Xcode everything does what I'm expecting.
But when I export as an Application, the images are still available and work fine, without me going into the Bundle for them.
So my question is - what determines which resource files I should go into the Bundle for, and which resource files I can assume will just be available by virtue of their being in my Supporting Files folder?
Many Thanks for reading this, and for any help you can give me.
I'm guessing that it depends on the class you are using and when you are only referring to them by name its just a convenience thing and XCode does the work nonetheless.
For example for a UIImage you can typeUIImage *image = [UIImage imageNamed:#"something"];
But XCode will do the NSSearchPathForDirectoriesInDomains or the [NSBoundle mainBoundle] thingy at build time.
You can only do the quick name referencing method on a few frequently-used classes and it's just for convenience.
This is my theory anyway, it requires confirmation.
I guess everybody read about the recent issues with the new iOS 5.
e.g. at http://iPhoneIncubator.com/blog/data-management/local-file-storage-in-ios-5
My Magazine-App holds about 1k html/css/image/video files for every issue and I want to know if anything is missing.
So my question is how to check all required files are present a very smart way?
I would expect iOS to clean caches atomically; i.e. iOS will either clean you app's cache or it will not. It shouldn't partially remove files from your cache. However, I don't believe this is documented behaviour, so it's a bad idea to assume this.
When you download your content, you have to know what to download for each issue, right? So you already have some kind of manifest file that references every file that is needed by each magazine. You should save this manifest locally so that you can refer to it when checking for the existence of files. You can still save this in the caches directory, if it's missing, you know your cache has been at least partially cleaned.
Also, I don't believe there's any guarantee that iOS won't clean caches while your application is running. As well as checking at the point where the user opens the magazine, you should check when your application becomes active after it has been put in the background, and your code should be robust in the face of missing files (i.e. pop up a warning message instead of crashing).
You could zip all the files relating to each issue in an archive (objective-c wrapper for zlib here, to make life easier for you). That way you can make sure that the system either deletes your issue or not, without having to worry about individual files.