I am working against a REST API where you can make a call and then receive a image or pdf. I am using URLSession.shared.dataTask to make the call and when there is a image the call is a success (but it takes quite a long time, more then 5 seconds) and I can show the image in a UIImageView. But when there is a pdf, I don't know how to handle the result. The API returns the image / pdf as a ”filestream”.
When I print the data to the console it prints the size (bytes) and its the same size as in the server so in some way I have the correct data, I just don't know how to view the pdf.
I am using swift 3, iOS 10, xcode 8.
First of all you may want to ask your question into two part. Please edit it and ask the second part again.
There are two parts in this topic
1. Downloading the PDF and save it in File System
2. Get the pdf that saved in File System and read it using UIWebView or UIDocumentInteractionController
So, I will explain for the first one.
The first one can be done if you use REST HTTP client : Alamofire : Elegant HTTP Networking in Swift. So no need to use URLSession for such case and you will have to write so many lines if you do. It's simple and easy. So, I want you to try it. If you need URLSession instead, leave comment.
So how to download pdf using Alamofire :
let destination: DownloadRequest.DownloadFileDestination = { _, _ in
let documentsURL = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask)[0]
//.documentDirectory means it will store in Application Document Folder
let fileURL = documentsURL.appendPathComponent("data.pdf")
return (fileURL, [.removePreviousFile, .createIntermediateDirectories])
}
Alamofire.download(urlString, to: destination).response { response in
print(response)
if response.error == nil, let filePath = response.destinationURL?.path {
// do anything you want with filePath here.
// Here what you have to do Step 2. (Read the file that you downloaded)
}
}
This download procedure doesn't include requesting download link with encoded parameters. It was just simple way.
Related
Reading a file into memory as bytes is easy:
let fileURL: URL = ...
Data(contentsOf: fileURL)
But that returns everything. I want to look at the first 16 bytes of a file, without loading the rest into memory. What's the best way to do this in Swift?
Use the FileHandle API, which has read(upToCount:):
let handle = try FileHandle(forReadingFrom: someURL)
let first16Bytes: Data? = try handle.read(upToCount: 16)
try handle.close()
Alternatively, you can read the file asynchronously, in which case you can control how many bytes you read by moving the iterator forward (calling AsyncIterator.next), or use prefix to get the first bytes.
I am really confused of all the different possibilities Swift has to save data and retrieve data. Save and retrieve data through userDefaults is easy, but for storing a lot of images this is not the best way to do it. Then there is Core Data, which is I think to complicated to use for such a simple task. I continued to read about DocumentDirectory, I think this is a good way to save and retrieve data. However, all the tutorials are mostly from swift 2.0 and below, and I can not read that very well. Is the document directory the best way to store and retrieve images? I am making an online application which contains downloading images from users. However, the images are all the same from the same user, so I want to store the images offline to save some bandwidth.
I want to store and retrieve images with a path I can specify in a String. Every user has a unique identifier which I want to use as a path. How can I accomplish this?
Saving in your file system is definitely the best approach to use in this scenario.
Have a look to this answer:
https://stackoverflow.com/a/39896556/5109911
if let data = UIImageJPEGRepresentation(image, 0.8) {
let filename = getDocumentsDirectory().appendingPathComponent("copy.png")
try? data.write(to: filename)
}
func getDocumentsDirectory() -> URL {
let paths = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask)
let documentsDirectory = paths[0]
return documentsDirectory
}
where image is your UIImage
To Store Image in User default you can just simply create an extension of UI image view like 👇🏻 below Code Click the link to show code
https://i.stack.imgur.com/xEhcr.png
How to Use::- yourimageviewName.saveImage(),OtherImageViewName.loadImage()
https://i.stack.imgur.com/wcrNX.png
I am trying to access a file I saved from my today extension.In my today extenson I did this to save the file:
func startRecording() {
let audioFilename = getDocumentsDirectory().appendingPathComponent("recording.m4a")
let settings = [
AVFormatIDKey: Int(kAudioFormatMPEG4AAC),
AVSampleRateKey: 12000,
AVNumberOfChannelsKey: 1,
AVEncoderAudioQualityKey: AVAudioQuality.high.rawValue
]
do {
audioRecorder = try AVAudioRecorder(url: audioFilename, settings: settings)
audioRecorder.delegate = self
audioRecorder.record()
recordButton.setTitle("Stop", for: .normal)
} catch {
finishRecording(success: false)
}
}
func getDocumentsDirectory() -> URL {
let paths = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask)
let documentsDirectory = paths[0]
return documentsDirectory
}
I then tried to get the data for my AVAudio Player in the main part of the project using this code:
let path = Bundle.main.path(forResource: "recording.m4a", ofType:nil)!
let url = URL(fileURLWithPath: path)
However, it gave the error: unexpectedly found nil while unwrapping an Optional value.
Thanks for the help.
Your extension saves the file to its document directory and your app code is looking for the file in the app bundle. The app bundle only contains the resources that are distributed with the app. You'll need to delve into the file system.
However, there's another problem. The extension and containing app don't share a documents directory. They each have their own container for writing data local to themselves. If you want to share data between them, it's a little more work. In summary:
Create an app group identifier for the app and the extension to share.
Use FileManager.containerURL(forSecurityApplicationGroupIdentifier:) to get the file URL for the shared container directory.
From the container URL, append the file name.
In the extension, you'll set up the AVAudioRecorder as usual and start recording.
In the main app, you'll want to use the NSFileCoordinator API to ensure that only one process is writing to the file at a time. Hopefully, the AVAudioRecorder uses the NSFileCoordinator API internally, although I didn't immediately find confirmation of this.
For more details about shared containers, see this blog post.
I just tried the same - record audio from a Today Extension. The code looks sooo familiar, so I'm taking a wild guess: you want to capture voice and send the file to the Google Speech API, correct?
Nonetheless, I think we're hitting restrictions of extensions: judging by https://developer.apple.com/library/content/qa/qa1872/_index.html extensions cannot record audio. The article has been writting for iOS 8, but I don't believe Apple ever lifted the restriction. Please correct me if I'm wrong, since I keep running into problems doing what OP does myself.
btw, check the result of audioRecorder.record(). It might be false and indicate that the capture never started (that's my error currently).
I use VLCKit in swift, so i created customize video player view
and i have external subtitles for movies from links, i read files from server and convert it so string
do {
let text = try NSString(contentsOfURL: NSURL(string: self.subtitleUrl)!, encoding: NSUTF8StringEncoding)
self.mediaPlayer.openVideoSubTitlesFromFile(text as String)
}catch {
print("Error")
}
and i called a function named "openVideoSubTitlesFromFile"
in player but not working
anyone can give me a solution
This method (which will be deprecated in the next major release of VLCKit) does only accept local file paths, no remote URLs. You need to download the subtitles file, cache it locally and provide the path of the stored file to the method. Additionally, you may only use this method after playback started.
I am writing a program in Swift that uses Just to fetch a webpage. I am new to Swift and know very little about it. My code is simple:
let r = Just.get("https://www.google.com/")
print(r.statusCode!)
print(r.text)
I would expect to see the contents of the downloaded web page, however, the output is:
200
nil
How can I retrieve the text contents of the response?
The problem is in your URL. If you'll try this, your response won't be nil:
let r = Just.get("https://medium.com/")
print(r.text!)
}