I have been attempting to use NSMutableArray's writeToFile:atomically:
But it has been pointed out to me that this approach is wrong: i.e. iPhone / Objective-C: NSMutableArray writeToFile won't write to file. Always returns NO
It looks like I'm going to have to read the guide on archiving that is referred to in one of the answers in the above link.
Would anyone care to share (or point me towards) some code that helps me accomplish this task?
The method, you've mentioned recursively validates that all the contained objects are property list objects before writing out the file.
Try this:
for (UIImage *image in arrayWithImages) {
NSString *pngPath = [NSHomeDirectory() stringByAppendingPathComponent:[NSString stringWithFormat:#"Documents/%#", #"nameOfTheImage.png"]];
UIImagePNGRepresentation(image) writeToFile:pngPath atomically:YES];
}
Maybe you can use [UIImageJPEGRepresentation(image, 1.0) writeToFile:jpgPath atomically:YES]; to write image as jpeg.
Related
I have solved the issue now, thanks for your help. I shouldn't have tried to save arrays with UITextViews, but I should have saved their text as strings instead. Here was the original question:
I have tried a lot, and googled a lot, but I can't solve this problem on my own. Whenever I try to save an array in userdefaults, it just is not working. I get the following error:
Thread 1: "Attempt to insert non-property list object (\n "<UITextView: 0x14001f800; frame = (0 0; 355 180); text = 'D'; clipsToBounds = YES; gestureRecognizers = <NSArray: 0x600003f01d10>; layer = <CALayer: 0x6000031c83e0>; contentOffset: {0, 0}; contentSize: {355, 30}; adjustedContentInset: {0, 0, 0, 0}>"\n) for key content"
I don't know what a non-property list object is. And I do not know how to solve the problem. Below is the lines of code that do not work.
var contentList: [Any] = []
let cl = defaults.array(forKey: "content")!
if cl.count != 0{
contentList += cl
}
contentList.append(label)
defaults.setValue(contentList, forKey: "content")
If I take out the last line of code by turning it into a comment everything runs just fine. How should I replace that line of code? I essentially want to save an array of UITextViews and make it larger every time I call a fucntion (this code is part of a larger function). The reason why I have created another two lists (cl and contentList) is that it helps me with a problem down the line. What I cannot understand however, is why the last line of code doesn't work. If anyone has any ideas, please help me, it would be much appreciated.
Use only String as stated in comments :
var contentList: [String] = []
let cl = defaults.array(forKey: "content")!
if cl.count != 0{
contentList += cl
}
If lbText = label.text {
contentList.append(lbText)
defaults.setValue(contentList, forKey: "content")
}
You can only store a very limited list of data types into UserDefaults, commonly referred to as "property list objects" (Since property list (or plist) files will only store the same data types.
To quote the Xcode docs on UserDefaults, in the section titled "Storing Default Objects":
A default object must be a property list—that is, an instance of (or for collections, a combination of instances of) NSData, NSString, NSNumber, NSDate, NSArray, or NSDictionary [or Data, String, NSNumber, Date, Array, or Dictionary types in Swift.] If you want to store any other type of object, you should typically archive it to create an instance of Data.
(I added the equivalent Swift types to the above quote in square brackets, since it looks like Apple hasn't updated it for Swift.)
That's worded a little awkwardly. The idea is that you can only store data of the types listed. Because the Array and Dictionary types are "container" types, you can store any combination of arrays and dictionaries that contain combinations of any of the above types. For example, you can store an array that contains a dictionary, 3 dates, 2 floats, a Double, some Data, and 2 arrays, and those dictionaries and arrays can contain other dictionaries and/or arrays.)
It is almost always wrong to archive UIView objects like UITextViews. You should save the text properties of your text views instead.
If you want to manage a vertical stack of UITextView objects, I suggest adding a vertical stack view to your user interface, and then writing code that adds or removes UITextView subviews to your stack view. You should be able to find plenty of examples of adding and removing objects from stack views online. (It's really easy.)
If you want to manage a scrolling list of feeds of arbitrary length, you might want to use a table view or collection view instead. Those require that you set up a data model and implement a "data source". That takes a little practice to get right, but is very powerful.
I'm new to the site and probably even newer to app development, however i'm learning slowly.. lol
So i hit my first big snag, I've researched all over on the web and can't find what I'm looking for, so here we go.
I'm creating an app that calls upon some user inputted files that can and do change on occasion. I've added the UIFileSharing option for this so users can upload files via iTunes.
There are 3 different types of files that will need to be used, a .opt, a .pkg, and a .txt.
Is there some way i can take the files from the directory, read them, and based off the file extension pull them and use them in a UIPickerView wheel? I'm really new at this so please forgive me when i ask you to be specific.
My assumption is to do this in a few steps, first read the files and sort them and place them in an array based on the extension, then use said array to populate the picker, and also to get the count for number of rows etc..
I guess the second two parts are pretty simple to figure out, just setting up a picker to use an array, i just need to know if its possible to build that array based on the user loaded files.
thanks in advance,
Chuck
You'll need to use the UIDocumentInteractionController class.
Simple Example
UIDocumentInteractionController * controller;
NSURL *fileURL=[NSURL fileURLWithPath:[self getFilePath]]
controller = [ UIDocumentInteractionController interactionControllerWithURL: fileURL ];
// How to get File From the Document Directory
-(NSString *)getFilePath{
NSString *documentPath= [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES)objectAtIndex:0];
return [documentPath stringByAppendingPathComponent:#"Your file name"]
}
I solved it guys, thanks for all the help.. Code is below, for anyone interested. Don't forget to define your arrays!
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,NSUserDomainMask, YES);
NSString *documentsPath = [paths objectAtIndex:0];
NSFileManager *fileManager = [NSFileManager defaultManager];
NSArray *bundleDirectory = [fileManager contentsOfDirectoryAtPath:documentsPath error:nil];
NSPredicate *Option = [NSPredicate predicateWithFormat:#"self ENDSWITH '.opt'"];
_OptionArray = [bundleDirectory filteredArrayUsingPredicate:Option];
_OptionPickerData = [_OptionArray copy];
I am accessing a plist file using the code below on a Cocoa with Objective-C application:
NSString *plistPath = [#"~/Library/Preferences/com.apple.mail.plist" stringByExpandingTildeInPath];
NSDictionary *plistData = [NSDictionary dictionaryWithContentsOfFile:plistPath];
NSArray *item = [plistData valueForKeyPath:#"MailAccounts.AccountName"];
NSLog(#"Account: %#", [item objectAtIndex:2]);
Which essentially returns the email address of the user (we also read some other information on other plist files) so we can add it to the About dialog.
I need now to read this information from the same plist files using C, not Objective-C. The files are not text, they are binary encoded plist files. Is there any way to read those property files from C?
Can I call NSDictionary etc from C? How?
Thanks for the help.
Of course you realize that Objective C is an extension of C, but in general, when I'm using plain ol' C, I use Core Foundation functions and objects instead of Objective C methods.
To your specific question: CFDictionary is toll-free bridged to NSDictionary and CFBundle to NSBundle. You can easily call CoreFoundation from plain ol' C.
You can get what you want with something like:
CFBundleRef mainBundle = CFBundleGetMainBundle();
CFDictionaryRef dictionaryRef = CFBundleGetInfoDictionary(mainBundle);
if(dictionaryRef)
{
CFArrayRef accountsItemsArrayRef = CFDictionaryGetValue(dictionaryRef, CFSTR("MailAccounts.AccountName");
if(accountsItemsArrayRef)
{
CFStringRef accountNameRef = (CFStringRef) CFArrayGetValueAtIndex(accountsItemsArrayRef, 2);
if(accountNameRef)
{
fprintf(stderr, "Account: %s", accountName.cStr());
}
}
}
I just typed this Core Foundation translation directly into this answer box and did no error or sanity checking, which you absolutely would need to do.
Here is a slightly older tutorial that explains a bit more.
Hope this helps to get you on the right path!
I'm currently trying to attach image files to a model directly from a zip file (i.e. without first saving them on a disk). It seems like there should be a clearer way of converting a ZipEntry to a Tempfile or File that can be stored in memory to be passed to another method or object that knows what to do with it.
Here's my code:
def extract (file = nil)
Zip::ZipFile.open(file) { |zip_file|
zip_file.each { |image|
photo = self.photos.build
# photo.image = image # this doesn't work
# photo.image = File.open image # also doesn't work
# photo.image = File.new image.filename
photo.save
}
}
end
But the problem is that photo.image is an attachment (via paperclip) to the model, and assigning something as an attachment requires that something to be a File object. However, I cannot for the life of me figure out how to convert a ZipEntry to a File. The only way I've seen of opening or creating a File is to use a string to its path - meaning I have to extract the file to a location. Really, that just seems silly. Why can't I just extract the ZipEntry file to the output stream and convert it to a File there?
So the ultimate question: Can I extract a ZipEntry from a Zip file and turn it directly into a File object (or attach it directly as a Paperclip object)? Or am I stuck actually storing it on the hard drive before I can attach it, even though that version will be deleted in the end?
UPDATE
Thanks to blueberry fields, I think I'm a little closer to my solution. Here's the line of code that I added, and it gives me the Tempfile/File that I need:
photo.image = zip_file.get_output_stream image
However, my Photo object won't accept the file that's getting passed, since it's not an image/jpeg. In fact, checking the content_type of the file shows application/x-empty. I think this may be because getting the output stream seems to append a timestamp to the end of the file, so that it ends up looking like imagename.jpg20110203-20203-hukq0n. Edit: Also, the tempfile that it creates doesn't contain any data and is of size 0. So it's looking like this might not be the answer.
So, next question: does anyone know how to get this to give me an image/jpeg file?
UPDATE:
I've been playing around with this some more. It seems output stream is not the way to go, but rather an input stream (which is which has always kind of confused me). Using get_input_stream on the ZipEntry, I get the binary data in the file. I think now I just need to figure out how to get this into a Paperclip attachment (as a File object). I've tried pushing the ZipInputStream directly to the attachment, but of course, that doesn't work. I really find it hard to believe that no one has tried to cast an extracted ZipEntry as a File. Is there some reason that this would be considered bad programming practice? It seems to me like skipping the disk write for a temp file would be perfectly acceptable and supported in something like Zip archive management.
Anyway, the question still stands:
Is there a way of converting an Input Stream to a File object (or Tempfile)? Preferably without having to write to a disk.
Try this
Zip::ZipFile.open(params[:avatar].path) do |zipfile|
zipfile.each do |entry|
filename = entry.name
basename = File.basename(filename)
tempfile = Tempfile.new(basename)
tempfile.binmode
tempfile.write entry.get_input_stream.read
user = User.new
user.avatar = {
:tempfile => tempfile,
:filename => filename
}
user.save
end
end
Check out the get_input_stream and get_output_stream messages on ZipFile.
I have a .plist with 2 key values in it. It is of type Dictionary. I am trying to write value to one of the key values. What's wrong with the code below? I also tried using type "Array". That option also does not work. How can I get it to work using Dictionary & also Array? Anyone has working code example? Thanks. I would appreciate any help.
NSString *filePath = #"myprefs.plist";
NSMutableDictionary* plistDict = [[NSMutableDictionary alloc] initWithContentsOfFile:filePath];
[plistDict setValue:#"test#test.com" forKey:#"Email"];
[plistDict writeToFile:filePath atomically: YES];
You did not initialize the path properly.
If "myprefs.plist" is inside the resources folder of your project then initialize like this:
NSString *filePath = [[NSBundle mainBundle]pathForResource:#"myprefs" ofType:#"plist"];
If its somewhere else in your computer, specify the whole path