I am attempting to create a file browsing app for iPads. I'm reluctant to use another app, such as Documents5, because I want to custom design it and bring in features we need.
Essentially I am looking to create an almost identical app to Documents5 with iCloud Drive support.
I have the code for viewing PDFs, MP3s etc., but I'm a bit bewildered with iCloud Drive integration and the menu interface for file browsing. Additionally, although I already have code for this, how do I link the files to the viewer/player?
iCloud Drive is pretty easy to implement. Assuming that your app has all entitlements and so on properly set up, you can move files to and delete files from iCloud by interacting with it like it is any other directory. You access the directory like this
- (NSString *)iCloudPath
{
NSURL *URL = [[NSFileManager defaultManager] URLForUbiquityContainerIdentifier:nil];
return [[URL path] stringByAppendingPathComponent:#"Documents"];
}
Moving files to this directory (to iCloud) is done like this
NSString *fileName = //the name of the file;
NSURL *fileURL = //the file you want to move;
NSString *iCloudPath = [self iCloudPath];
[[NSFileManager defaultManager] setUbiquitous:YES itemAtURL:fileURL destinationURL:[NSURL fileURLWithPath:[iCloudPath stringByAppendingPathComponent:fileName]] error:nil];
The easiest way to display files is through a table view. You can implement a system where the file paths are stored in an array, so that when a cell is selected, you can decide how to open it based off of the file's extension. For example, let's say your table view looks like this
-----------------
| video.mp4 |
-----------------
| text.txt |
-----------------
| file.pdf |
if your user selects row 1 (text.txt), you could implement something like this
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
NSString *filePath = self.files[indexPath.row];
NSString *fileExtension = [filePath pathExtension];
if ([fileExtension isEqualToString:#"txt"])
{
//open the text file
}
}
Related
I am saving video/image in document directory.Now once the image is saved in document directory I want to save its reference in my local database.So I am thinking I can save URL of the image in the local database.
So is it constant throughout my app?
It's not constant, i have observed every time you launch the app it'll be different, but your data is moved to this new path. You can save your file name in your database, and dynamically append this file name to NSDocument directory.
- (NSString *)documentsFilePath:(NSString *)fileName {
NSArray *dirPaths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *docsDir = [dirPaths firstObject];
NSString *filePath = [docsDir stringByAppendingPathComponent:fileName];
return filePath;
}
- (void)storeFile:(NSString *)fileName {
NSString *filePath = [self documentsFilePath:fileName];
// create if needed
if (![[NSFileManager defaultManager] fileExistsAtPath:filePath]) {
// Write your data to file system here...
}
}
- (void)deleteFile:(NSString *)fileName {
NSString *filePath = [self documentsFilePath:fileName];
if ([[NSFileManager defaultManager] fileExistsAtPath:filePath]) {
NSError *deleteErr = nil;
[[NSFileManager defaultManager] removeItemAtPath:filePath error:&deleteErr];
if (deleteErr) {
NSLog(#"Can't delete %#: %#", filePath, deleteErr);
}
}
}
Please handle nil checks and store only filename in DB
No, it's not constant. Whenever your app reinstall or updated on device the document directory will change, because when app installed on device os made an directory for app with some random id and each install this random it get changed by OS.
So, you need to make it dynamic own your own, like store the file name only and append the document directory path while using it.
I would suggest only saving the filename or subdirectory/filename (if you have a subdirectory) in the database and then only attaching that to the NSDocumentDirectory.
This will ensure that you always know where the file is...
NSDocumentDirectory is however consistent accross updates, so the files should remain in the document directory even if you update...
I'm getting this behaviour using Xcode 8.0. The problem is, after downloading a file and storing it on documents directory (code provided below), QLPreviewController only displays document's name and size. The property currentPreviewItem returns the correct path document. What's even more strange, is that if I try to open that document from another controller in my app, it works fine. I've implemented both QLPreviewControllerDelegate and QLPreviewControllerDataSource.
Code for downloading and saving document:
dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_HIGH, 0), ^{
NSURL *url = [NSURL URLWithString:file[#"url"]];
NSData *data = [NSData dataWithContentsOfURL:url];
if (!data) {
completion([NSError new]);
return;
}
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *path = [[paths objectAtIndex:0] stringByAppendingPathComponent:AppName];
path = [path stringByAppendingPathComponent:file[#"name"]];
file[#"filePath"] = [NSURL fileURLWithPath:path];
dispatch_async(dispatch_get_main_queue(), ^{
[[NSFileManager defaultManager] createFileAtPath:path contents:data attributes:nil];
completion(nil);
});
});
Then, when user selects a document I use the content saved on #"filePath" to show QLPreviewController. I've tried pushing it and presenting it modally and in both cases it just displays a gray page with document's name and size.
File wasn't showed because downloaded contents didn't contain file's extension. When I tried opening it in other controller, it worked because I temporary used another file name containing the correct extension. So I solved the problem adding the extension .pdf to downloaded files that didn't include it. This made QLViewController displaying correctly the file.
In my case, a file was created with the correct name, but the file contained an error message from the server, thus not representing the expected file structure.
I use this code to save some PDF data to a file, send it to another app using the "Open In" menu, then delete the file when that's done:
- (void)openIn:(NSData *)fileData {
// save the PDF data to a temporary file
NSString *fileName = [NSString stringWithFormat:#"%#.pdf", self.name];
NSString *filePath = [NSString stringWithFormat:#"%#/Documents/%#", NSHomeDirectory(), fileName];
BOOL result = [fileData writeToFile:filePath atomically:TRUE];
if (result) {
NSURL *URL = [NSURL fileURLWithPath:filePath];
UIDocumentInteractionController *controller = [[UIDocumentInteractionController interactionControllerWithURL:URL] retain];
controller.delegate = self;
[controller presentOpenInMenuFromBarButtonItem:self.openInButton animated:TRUE];
}
}
- (void)documentInteractionControllerDidDismissOpenInMenu:(UIDocumentInteractionController *)controller {
// when the document interaction controller finishes, delete the temporary file
NSString *fileName = [NSString stringWithFormat:#"%#.pdf", self.name];
NSString *filePath = [NSString stringWithFormat:#"%#/Documents/%#", NSHomeDirectory(), fileName];
[[NSFileManager defaultManager] removeItemAtPath:filePath error:nil];
}
This has worked fine until iOS 8. Now, the file is created and I can verify that it contains the correct content, the Open In menu appears, I can select an app, and the delegate method runs and cleans up the file. But instead of iOS switching to the selected app and copying the file into it as it did before, the Open In menu simply closes when I select an app, and the file is not copied.
This works if I give the UIDocumentInteractionController an existing file. It also works if I use the provided fileData but change the destination filename to the filename of an existing file. This suggests a permissions problem -- as if new files are created in iOS 8 with default permissions that UIDocumentInteractionController can't read.
Does anyone know what's happening and how I can work around it?
It looks like the order of operations has changed slightly in iOS 8. DidDismissOpenInMenu used to run after the file was finished sending, but now it runs after the file begins sending. This means my cleanup code was sometimes running before the file was finished sending, leaving no file to send. I figured this out after noticing that smaller files were being sent okay; apparently the processing for smaller files was finishing before my cleanup code got them, but the processing for larger files was not.
To ensure the correct timing, but also clean up files that are created when the user opens the DocumentInteractionController and then dismisses the controller without doing anything, I changed my methods like this:
- (void)openIn:(NSData *)fileData {
// save the PDF data to a temporary file
NSString *fileName = [NSString stringWithFormat:#"%#.pdf", self.name];
NSString *filePath = [NSString stringWithFormat:#"%#/Documents/%#", NSHomeDirectory(), fileName];
BOOL result = [fileData writeToFile:filePath atomically:TRUE];
if (result) {
self.sendingFile = FALSE;
NSURL *URL = [NSURL fileURLWithPath:filePath];
UIDocumentInteractionController *controller = [[UIDocumentInteractionController interactionControllerWithURL:URL] retain];
controller.delegate = self;
[controller presentOpenInMenuFromBarButtonItem:self.openInButton animated:TRUE];
}
}
- (void)documentInteractionController:(UIDocumentInteractionController *)controller willBeginSendingToApplication:(NSString *)application {
// the user chose to send the file, so we shouldn't clean it up until that's done
self.sendingFile = TRUE;
}
- (void)documentInteractionControllerDidDismissOpenInMenu:(UIDocumentInteractionController *)controller {
if (!self.sendingFile) {
// the user didn't choose to send the file, so we can clean it up now
[self openInCleanup];
}
}
- (void)documentInteractionController:(UIDocumentInteractionController *)controller didEndSendingToApplication:(NSString *)application {
// the user chose to send the file, and the sending is finished, so we can clean it up now
[self openInCleanup];
self.sendingFile = FALSE;
}
- (void)openInCleanup {
// delete the temporary file
NSString *fileName = [NSString stringWithFormat:#"%#.pdf", self.name];
NSString *filePath = [NSString stringWithFormat:#"%#/Documents/%#", NSHomeDirectory(), fileName];
[[NSFileManager defaultManager] removeItemAtPath:filePath error:nil];
}
Update for iOS 11
Before iOS 11, it seems that the operating system kept a copy of the file available until the receiving app was finished reading it, even though my cleanup function ran as soon as the file was sent out from my app. In iOS 11, this changed and the receiving app fails to read the file because my app deletes it before that's done. So now instead of saving the temporary file to Documents and using the openInCleanup method to delete it immediately, I'm saving the temporary file to tmp and emptying the tmp folder next time the app launches. This approach should also work with older iOS versions. Just remove openInCleanup, change Documents to tmp in the paths, and add this to applicationDidFinishLaunching:
// clear the tmp directory, which will contain any files saved for Open In
NSString *tmpDirectory = [NSString stringWithFormat:#"%#/tmp", NSHomeDirectory()];
NSArray *tmpFiles = [[NSFileManager defaultManager] contentsOfDirectoryAtPath:tmpDirectory error:NULL];
for (NSString *tmpFile in tmpFiles) {
[[NSFileManager defaultManager] removeItemAtPath:[NSString stringWithFormat:#"%#/%#", tmpDirectory, tmpFile] error:NULL];
}
After reading this post, I already hoped to have found the solution to a similar problem:
For me, as of iOS 8, sharing was only working with Mail.app. It was failing for Dropbox, etc.
Turns out it was something else:
On my interactionController I was setting an annotation like this:
interactionController.annotation = #"Some text"
For unknown reasons, this prevented Dropbox to open at all. There were no error messages or anything. Removing this line solved the issue.
I have made an app that creates a pdf and stores it in the apps documents folder. I would now like to open it and view it from within the app when a 'View pdf' UIButton is pressed.
I have already looked at a few questions on here and I have considered either a separate view controller or perhaps a scroll view.
What is the best method to use?
UPDATE:
I have followed advice and I am trying to use QLPreviewController. I have added QuickLook framework and now have the following, but I am stuck on how to get the path recognised in the pathForResource. Any suggestions?
- (NSInteger)numberOfPreviewItemsInPreviewController:(QLPreviewController *)controller
{
return 1;
}
- (id <QLPreviewItem>)previewController:(QLPreviewController *)controller previewItemAtIndex:(NSInteger)index
{
NSString *path=[[NSBundle mainBundle] pathForResource:[pdfPathWithFileName] ofType:nil];
return [NSURL fileURLWithPath:path];
}
- (IBAction)viewPdfButton:(id)sender {
NSString *filename= #"ObservationPDF.pdf";
NSArray *path = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documnetDirectory = [path objectAtIndex:0];
NSString *pdfPathWithFileName = [documnetDirectory stringByAppendingPathComponent:filename];
[self generatePdf: pdfPathWithFileName];
QLPreviewController *previewController=[[QLPreviewController alloc]init];
previewController.delegate=self;
previewController.dataSource=self;
[self presentViewController:previewController animated:YES completion:nil];
}
If the PDF file is in the app documents folder then you shouldn't be thinking about passing it to another app, you should be looking to present the file inside the app. 2 general options:
Add a UIWebView and load the local file into it
Use QLPreviewController to show a new view containing the PDF
The web view is simple and requires no transition on the UI. The preview controller needs a transition but offers some sharing / printing support for free.
This line is confused (and invalid syntax by the looks of it):
NSString *path=[[NSBundle mainBundle] pathForResource:[pdfPathWithFileName] ofType:nil];
You only use NSBundle to get items out of the bundle, and that isn't what you have. You should just be creating the URL with the file path where you save the file:
[NSURL fileURLWithPath:pdfPathWithFileName];
(which you may store or you may need to recreate in the same way as when you save the file)
I'm trying to copy a downloaded file to a specific folder in the app's documents directory but can't seem to get it working. The code I'm using is:
NSString *itemPathString = #"http://pathToFolder/folder/myFile.doc";
NSURL *myUrl = [NSURL URLWithString:itemPathString];
NSArray *paths = [fm URLsForDirectory:NSDocumentDirectory inDomains:NSUserDomainMask];
NSURL *folderPath = [[paths objectAtIndex:0] URLByAppendingPathComponent:#"folder"];
NSURL *itemURL = [documentsPath URLByAppendingPathComponent:#"myFile.doc"];
// copy to documents directory asynchronously
dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
NSFileManager *theFM = [[NSFileManager alloc] init];
NSError *error;
[theFM copyItemAtURL:myUrl toURL:itemURL error:&error];
}
});
I can retrieve the file OK but can't copy it. Can anyone tell me if there's anything wrong with the above code?
If downloading a file from a server, if it's a reasonably small file (e.g. measured in kb, not mb), you can use dataWithContentsOfURL. You can use that method to load the file into memory, and then use the NSData instance method writeToFile to save the file.
But, if it's a larger file, you will want to use NSURLConnection, which doesn't try to hold the whole file in memory, but rather writes it to the file system when appropriate. The trick here, though, is if you want to download multiple files, you either have to download them sequentially, or encapsulate the NSURLConnection and the NSOutputStream such that you can have separate copies of those for each simultaneous download.
I have uploaded a project, Download Manager that demonstrates what a NSURLConnection implementation might look like, but it's non-trivial. You might rather want to contemplate using an established, third-party library, such as ASIHTTPRequest or RestKit.
If you want to access a folder with a given name you should check if it exists and if not create it. That could quite easy be done like this:
NSString *folder = [documentsPath stringByAppendingPathComponent:folderName];
NSFileManager *fileManager = [NSFileManager defaultManager];
NSError *error = nil;
if (![fileManager fileExistsAtPath:folder]) {
[fileManager createDirectoryAtPath:folder withIntermediateDirectories:YES attributes:nil error:&error];
}
if (error != nil) {
NSLog(#"Some error: %#", error);
return;
}
EDIT
If you want to check if the folder was created properly on your device got to Organizer -> Devices -> [YourDevelopingDeviceWhereTheAppWasInstalled] -> Applications -> [YourApplication]
In the lower section you should at least see some folders like Documents. And if successful your created folders as well.
You need to create any intermediate directories prior to copying files. Check in the Simulator folder to see wether the "folder" directory is created in the applications Documents-folder.
Path to simulator is /Users/$username/Library/Application Support/iPhone Simulator/