NetNewsWire/Shared/Favicons/FaviconURLFinder.swift

64 lines
1.9 KiB
Swift

//
// FaviconURLFinder.swift
// NetNewsWire
//
// Created by Brent Simmons on 11/20/17.
// Copyright © 2017 Ranchero Software. All rights reserved.
//
import Foundation
import RSParser
// The favicon URLs may be specified in the head section of the home page.
struct FaviconURLFinder {
/// Finds favicon URLs in a web page.
/// - Parameters:
/// - homePageURL: The page to search.
/// - ignoredTypes: An array of uniform type identifiers to ignore.
/// - completion: A closure called when the links have been found.
/// - urls: An array of favicon URLs as strings.
static func findFaviconURLs(with homePageURL: String, ignoredTypes ignoredTypes: [String]? = nil, _ completion: @escaping (_ urls:[String]?) -> Void) {
guard let _ = URL(string: homePageURL) else {
completion(nil)
return
}
var ignoredMimeTypes = [String]()
var ignoredExtensions = [String]()
if let ignoredTypes = ignoredTypes {
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])
}
}
}
// 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?.faviconLinks.filter({ (faviconLink) -> Bool in
if faviconLink.type != nil {
if ignoredMimeTypes.contains(faviconLink.type) {
return false
}
} else {
if let url = URL(string: faviconLink.urlString!), ignoredExtensions.contains(url.pathExtension) {
return false
}
}
return true
}).map { $0.urlString! }
completion(faviconURLs)
}
}
}