CODEWITHSUNDEEP
iosswiftpdfswift3uiwebview
Alexandre Lara
Alexandre Lara

Reputation: 2568

How to load a PDF from a Base64 string in a UIWebView

I'm using an API that is returning a Base64 string, something like this:

data:application/pdf;base64,**BASE64STRING**

Where BASE64STRING is what I need to display the PDF.

So far I only created a Data object that gets the Base64 string:

let data = Data(base64Encoded: BASE64STRING)

And I tried to load it in the webview:

webView.load(data!, mimeType: "application/pdf", textEncodingName: "", baseURL: URL(string: "")!)

The problem is that I don't have a local PDF file, so I don't know what I should put in baseURL. Currently it's giving me a fatal error: unexpectedly found nil while unwrapping an Optional value

How can I load the PDF in the webView? Is there any better way to do that?

Upvotes: 3

Views: 6200

Answers (5)

Shakeel Ahmed
Shakeel Ahmed

Reputation: 6013

Swift 5+ Very Easy and Smooth Solution

let base64PDF = "m5hbWVfaWQiOiJ1aWQiLCJRSUQiOiIyNzg1ODYwNDM3NSIsIlVVSUQiOiIwMDE2M0U2Ri1EREMyLTFFRTktQUE5MS0wOEYxMDFEODU4NTYiLCJFbWFpbCI6IlNBSUYuUkVITUFOQEFBQlFBVEFSLkNPTSIs"
if let data = Data(base64Encoded: base64PDF, options: Data.Base64DecodingOptions.ignoreUnknownCharacters) as Data? {
    self.webKitView.load(data, mimeType: "application/pdf", characterEncodingName: "", baseURL: nil)
}

Upvotes: -1

Medhi
Medhi

Reputation: 3225

For Swift 5, here a complete example with no force unwrapped and temporary file:

guard let data = Data(base64Encoded: base64), let fileUrl = try? saveTemporaryFile(from: data, filename: fileName) else {
    // error handling
    return
}

webView.load(data, mimeType: "application/pdf", textEncodingName: "", baseURL: fileUrl)

And the utility function to save the data in local temp file:

func saveTemporaryFile(from data: Data, filename: String? = nil) throws -> URL {
    let filename = filename ?? UUID().uuidString
    let fileURL = URL(fileURLWithPath: NSTemporaryDirectory(), isDirectory: true).appendingPathComponent(filename)
    try? FileManager.default.removeItem(at: fileURL)
    try data.write(to: fileURL)

    return fileURL
}

Upvotes: 2

Anirudha Mahale
Anirudha Mahale

Reputation: 2596

First convert the base64String to NSData and then convert to Data and use it.

PDF files are binary files so they can't be represented as UITF8 encoded string directly.

if let data = NSData(base64Encoded: base64String, options: NSData.Base64DecodingOptions.ignoreUnknownCharacters) as Data? {
    self.webView.load(data, mimeType: "application/pdf", characterEncodingName: "", baseURL: URL(fileURLWithPath: ""))
}

Upvotes: 0

Gauraw
Gauraw

Reputation: 404

Try this 

webView.load(data, mimeType: "application/pdf", textEncodingName: "utf-8", baseURL: URL(fileURLWithPath: ""))

Upvotes: 0

Alexandre Lara
Alexandre Lara

Reputation: 2568

I solved the problem, despite that I'm not sure if it's a good approach, the solution is to put any valid URL in baseUrl:

webView.load(data!, mimeType: "application/pdf", textEncodingName: "", baseURL: URL(string: "https://www.google.com")!)

Upvotes: 3

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