Swift: Read pdf file into pdf application reader

Question

How can I display all applications that can read pdf file (adobe pdf reader for example) when a button is clicked? I searched but I found that the majority use UIWebView to disp

Answer 1

You can go with UIDocumentInteractionController, it will handle all for you like zooming pdf, scrolling, showing suitable app to handle the pdf.

SWIFT 2.3:

import UIKit

class ViewController:UIViewController, UIDocumentInteractionControllerDelegate {

var documentController: UIDocumentInteractionController = UIDocumentInteractionController()

override func viewDidLoad() {
    super.viewDidLoad()
    downloadFileForfileObject("https://d0.awsstatic.com/whitepapers/KMS-Cryptographic-Details.pdf")
}

override func viewWillAppear(animated: Bool) {
    super.viewWillAppear(animated)
}

func downloadFileForfileObject(url: String) { //Download pdf File asynchronosly
    let documentURL = NSURL(string: url)
    let documentsURLPath = NSFileManager.defaultManager().URLsForDirectory(.CachesDirectory, inDomains: .UserDomainMask).first! as NSURL

    let fileExtension = ((documentURL!.pathComponents)?.last)! as String
    let request: NSURLRequest = NSURLRequest(URL: documentURL!, cachePolicy: NSURLRequestCachePolicy.ReturnCacheDataElseLoad, timeoutInterval: 60)
    let fileURLPath = documentsURLPath.URLByAppendingPathComponent("\(fileExtension)")

    let sessionCobfig = NSURLSessionConfiguration()
    let session = NSURLSession(configuration: sessionCobfig, delegate: nil, delegateQueue: nil)
    let task = session.dataTaskWithRequest(request) { (data, response, error) in
        if error == nil {
            self.openSelectedDocumentFromURL((fileURLPath?.path!)!)
        } else {
            print(error?.localizedDescription)
        }
    }
    task.resume()
}

func openSelectedDocumentFromURL(documentURLString: String) {
    let documentURL: NSURL = NSURL(fileURLWithPath: documentURLString)
    documentController = UIDocumentInteractionController(URL: documentURL)
    documentController.delegate = self
    documentController.presentPreviewAnimated(true)
}

// MARK: - UIDocumentInteractionViewController delegate methods

func documentInteractionControllerViewControllerForPreview(controller: UIDocumentInteractionController) -> UIViewController {
    return self
}

}

Call downloadFileForfileObject() in viewDidLoad method with your pdf url as a parameter. The pdf will be automatically shown by UIDocumentInteractionController delegate method.

SWIFT 3:

import UIKit

class MOViewController:UIViewController, UIDocumentInteractionControllerDelegate {

var documentController: UIDocumentInteractionController = UIDocumentInteractionController()

override func viewDidLoad() {
    super.viewDidLoad()
    downloadFileForfileObject(url: "https://d0.awsstatic.com/whitepapers/KMS-Cryptographic-Details.pdf")
}

override func viewWillAppear(_ animated: Bool) {
    super.viewWillAppear(animated)

}

func downloadFileForfileObject(url: String) { //Download pdf File asynchronosly
    let documentURL = NSURL(string: url)
    let documentsURLPath = FileManager.default.urls(for: .cachesDirectory, in: .userDomainMask).first! as NSURL

    let fileExtension = ((documentURL!.pathComponents)?.last)! as String
    let request: URLRequest = URLRequest(url: documentURL! as URL, cachePolicy: NSURLRequest.CachePolicy.returnCacheDataElseLoad, timeoutInterval: 60)
    let fileURLPath = documentsURLPath.appendingPathComponent("\(fileExtension)")

    let sessionConfig = URLSessionConfiguration.default
    let session = URLSession(configuration: sessionConfig, delegate: nil, delegateQueue: nil)

    let teask = session.dataTask(with: request) { (data, response, error) in
        if (error == nil) {
            // Success
            self.openSelectedDocumentFromURL(documentURLString: fileURLPath!.path)
        } else {
            print(error?.localizedDescription)
        }
    }
    teask.resume()
    }

func openSelectedDocumentFromURL(documentURLString: String) {
    let documentURL: NSURL = NSURL(fileURLWithPath: documentURLString)
    documentController = UIDocumentInteractionController(url: documentURL as URL)
    documentController.delegate = self
    documentController.presentPreview(animated: true)
}


// MARK: - UIDocumentInteractionViewController delegate methods

func documentInteractionControllerViewControllerForPreview(_ controller: UIDocumentInteractionController) -> UIViewController {
    return self
}

Document download verification: You check whether document is downloading or not by follows, see image.

Output:

Thanks:)