NetNewsWire/Shared/Favicons/FaviconURLFinder.swift

72 lines
2.0 KiB
Swift

//
// FaviconURLFinder.swift
// NetNewsWire
//
// Created by Brent Simmons on 11/20/17.
// Copyright © 2017 Ranchero Software. All rights reserved.
//
import Foundation
import CoreServices
import RSParser
// The favicon URLs may be specified in the head section of the home page.
struct FaviconURLFinder {
private static var ignoredMimeTypes = [String]()
private static var ignoredExtensions = [String]()
/// Uniform types to ignore when finding favicon URLs.
static var ignoredTypes: [String]? {
didSet {
guard let ignoredTypes = ignoredTypes else {
return
}
for type in ignoredTypes {
if let mimeTypes = UTTypeCopyAllTagsWithClass(type as CFString, kUTTagClassMIMEType)?.takeRetainedValue() {
ignoredMimeTypes.append(contentsOf: mimeTypes as! [String])
}
if let extensions = UTTypeCopyAllTagsWithClass(type as CFString, kUTTagClassFilenameExtension)?.takeRetainedValue() {
ignoredExtensions.append(contentsOf: extensions as! [String])
}
}
}
}
/// Finds favicon URLs in a web page.
/// - Parameters:
/// - homePageURL: The page to search.
/// - completion: A closure called when the links have been found.
/// - urls: An array of favicon URLs as strings.
static func findFaviconURLs(with homePageURL: String, _ completion: @escaping (_ urls: [String]?) -> Void) {
guard let _ = URL(unicodeString: homePageURL) else {
completion(nil)
return
}
// If the favicon has an explicit type, check that for an ignored type; otherwise, check the file extension.
HTMLMetadataDownloader.downloadMetadata(for: homePageURL) { (htmlMetadata) in
let faviconURLs = htmlMetadata?.favicons.compactMap({ (favicon) -> String? in
if let type = favicon.type {
if ignoredMimeTypes.contains(type) {
return nil
}
}
else {
if let urlString = favicon.urlString, let url = URL(string: urlString), ignoredExtensions.contains(url.pathExtension) {
return nil
}
}
return favicon.urlString
})
completion(faviconURLs)
}
}
}