Created
January 12, 2023 22:19
-
-
Save armstrongnate/7df55f6d47d7e71e8feb390278416936 to your computer and use it in GitHub Desktop.
Render SVG from data in swift
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| private func imageFrom(url: URL?, data: Data, response: HTTPURLResponse? = nil) -> AnyPublisher<UIImage?, Error> { | |
| let type = response?.mimeType | |
| if type?.hasPrefix("image/svg") == true || url?.pathExtension.lowercased() == "svg" { | |
| return svgFrom(data: data) | |
| } | |
| return Just(UIImage(data: data)).setFailureType(to: Error.self).eraseToAnyPublisher() | |
| } | |
| private func svgFrom(data: Data) -> AnyPublisher<UIImage?, Error> { | |
| let dataUri = "data:image/svg+xml;base64,\(data.base64EncodedString())" | |
| let html = """ | |
| <!doctype html> | |
| <meta name="viewport" content="width=device-width,initial-scale=1,user-scalable=no"> | |
| <style>*{margin:0;padding:0;height:100%;width:100%;}</style> | |
| <img src="\(dataUri)" style="object-position:center;object-fit:contain;" | |
| onload="setTimeout(()=>webkit.messageHandlers.svg.postMessage(''),17)" | |
| /> | |
| """ | |
| return Future { promise in | |
| DispatchQueue.main.async { | |
| let config = WKWebViewConfiguration() | |
| config.websiteDataStore = .nonPersistent() | |
| var webView: WKWebView? = WKWebView(frame: CGRect(x: 0, y: 0, width: 24, height: 24), configuration: config) | |
| webView?.backgroundColor = .clear | |
| webView?.isOpaque = false | |
| webView?.loadHTMLString(html, baseURL: nil) | |
| webView?.handle("svg") { _ in | |
| webView?.takeSnapshot(with: nil) { snapshot, error in | |
| webView = nil | |
| if let error = error { | |
| promise(.failure(error)) | |
| } else { | |
| promise(.success(snapshot)) | |
| } | |
| } | |
| } | |
| } | |
| } | |
| .eraseToAnyPublisher() | |
| } | |
| typealias MessageHandler = (WKScriptMessage) -> Void | |
| extension WKWebView { | |
| func handle(_ name: String, handler: @escaping MessageHandler) { | |
| let passer = MessagePasser(handler: handler) | |
| configuration.userContentController.removeScriptMessageHandler(forName: name) | |
| configuration.userContentController.add(passer, name: name) | |
| } | |
| } | |
| private class MessagePasser: NSObject, WKScriptMessageHandler { | |
| let handler: MessageHandler | |
| init(handler: @escaping MessageHandler) { | |
| self.handler = handler | |
| super.init() | |
| } | |
| func userContentController(_ userContentController: WKUserContentController, didReceive message: WKScriptMessage) { | |
| handler(message) | |
| } | |
| } |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment