mirror of
https://github.com/Ranchero-Software/NetNewsWire.git
synced 2024-12-27 10:02:37 +01:00
101 lines
2.3 KiB
Swift
101 lines
2.3 KiB
Swift
//
|
|
// FeaturedImageDownloader.swift
|
|
// NetNewsWire
|
|
//
|
|
// Created by Brent Simmons on 11/26/17.
|
|
// Copyright © 2017 Ranchero Software. All rights reserved.
|
|
//
|
|
|
|
import Foundation
|
|
import Articles
|
|
import RSCore
|
|
import RSParser
|
|
|
|
final class FeaturedImageDownloader {
|
|
|
|
private let imageDownloader: ImageDownloader
|
|
private var articleURLToFeaturedImageURLCache = [String: String]()
|
|
private var articleURLsWithNoFeaturedImage = Set<String>()
|
|
private var urlsInProgress = Set<String>()
|
|
|
|
init(imageDownloader: ImageDownloader) {
|
|
|
|
self.imageDownloader = imageDownloader
|
|
}
|
|
|
|
func image(for article: Article) -> RSImage? {
|
|
|
|
if let url = article.imageURL {
|
|
return image(forFeaturedImageURL: url)
|
|
}
|
|
if let articleURL = article.url {
|
|
return image(forArticleURL: articleURL)
|
|
}
|
|
return nil
|
|
}
|
|
|
|
func image(forArticleURL articleURL: String) -> RSImage? {
|
|
|
|
if articleURLsWithNoFeaturedImage.contains(articleURL) {
|
|
return nil
|
|
}
|
|
|
|
if let featuredImageURL = cachedURL(for: articleURL) {
|
|
return image(forFeaturedImageURL: featuredImageURL)
|
|
}
|
|
findFeaturedImageURL(for: articleURL)
|
|
return nil
|
|
}
|
|
|
|
func image(forFeaturedImageURL featuredImageURL: String) -> RSImage? {
|
|
if let data = imageDownloader.image(for: featuredImageURL) {
|
|
return RSImage(data: data)
|
|
}
|
|
return nil
|
|
}
|
|
|
|
}
|
|
|
|
private extension FeaturedImageDownloader {
|
|
|
|
func cachedURL(for articleURL: String) -> String? {
|
|
|
|
return articleURLToFeaturedImageURLCache[articleURL]
|
|
}
|
|
|
|
func cacheURL(for articleURL: String, _ featuredImageURL: String) {
|
|
|
|
articleURLsWithNoFeaturedImage.remove(articleURL)
|
|
articleURLToFeaturedImageURLCache[articleURL] = featuredImageURL
|
|
}
|
|
|
|
func findFeaturedImageURL(for articleURL: String) {
|
|
|
|
guard !urlsInProgress.contains(articleURL) else {
|
|
return
|
|
}
|
|
urlsInProgress.insert(articleURL)
|
|
|
|
HTMLMetadataDownloader.downloadMetadata(for: articleURL) { (metadata) in
|
|
|
|
self.urlsInProgress.remove(articleURL)
|
|
|
|
guard let metadata = metadata else {
|
|
return
|
|
}
|
|
self.pullFeaturedImageURL(from: metadata, articleURL: articleURL)
|
|
}
|
|
}
|
|
|
|
func pullFeaturedImageURL(from metadata: RSHTMLMetadata, articleURL: String) {
|
|
|
|
if let url = metadata.bestFeaturedImageURL() {
|
|
cacheURL(for: articleURL, url)
|
|
let _ = image(forFeaturedImageURL: url)
|
|
return
|
|
}
|
|
|
|
articleURLsWithNoFeaturedImage.insert(articleURL)
|
|
}
|
|
}
|