Add basic ExtensionPoint support.

Shared/Extensions/ArticleUtilities.swift

@@ -0,0 +1,202 @@
+//
+//  ArticleUtilities.swift
+//  NetNewsWire
+//
+//  Created by Brent Simmons on 7/25/15.
+//  Copyright © 2015 Ranchero Software, LLC. All rights reserved.
+//
+
+import Foundation
+import RSCore
+import Articles
+import Account
+
+// These handle multiple accounts.
+
+@discardableResult
+func markArticles(_ articles: Set<Article>, statusKey: ArticleStatus.Key, flag: Bool) -> Set<Article>? {
+	
+	let d: [String: Set<Article>] = accountAndArticlesDictionary(articles)
+	var updatedArticles = Set<Article>()
+
+	for (accountID, accountArticles) in d {
+		
+		guard let account = AccountManager.shared.existingAccount(with: accountID) else {
+			continue
+		}
+
+		if let accountUpdatedArticles = account.markArticles(accountArticles, statusKey: statusKey, flag: flag) {
+			updatedArticles.formUnion(accountUpdatedArticles)
+		}
+
+	}
+	
+	return updatedArticles
+}
+
+private func accountAndArticlesDictionary(_ articles: Set<Article>) -> [String: Set<Article>] {
+	
+	let d = Dictionary(grouping: articles, by: { $0.accountID })
+	return d.mapValues{ Set($0) }
+}
+
+extension Article {
+	
+	var webFeed: WebFeed? {
+		return account?.existingWebFeed(withWebFeedID: webFeedID)
+	}
+	
+	var preferredLink: String? {
+		if let url = url, !url.isEmpty {
+			return url
+		}
+		if let externalURL = externalURL, !externalURL.isEmpty {
+			return externalURL
+		}
+		return nil
+	}
+	
+	var body: String? {
+		return contentHTML ?? contentText ?? summary
+	}
+	
+	var logicalDatePublished: Date {
+		return datePublished ?? dateModified ?? status.dateArrived
+	}
+	
+	var isAvailableToMarkUnread: Bool {
+		guard let markUnreadWindow = account?.behaviors.compactMap( { behavior -> Int? in
+			switch behavior {
+			case .disallowMarkAsUnreadAfterPeriod(let days):
+				return days
+			default:
+				return nil
+			}
+		}).first else {
+			return true
+		}
+		
+		if logicalDatePublished.byAdding(days: markUnreadWindow) > Date() {
+			return true
+		} else {
+			return false
+		}
+	}
+
+	func iconImage() -> IconImage? {
+		if let authors = authors, authors.count == 1, let author = authors.first {
+			if let image = appDelegate.authorAvatarDownloader.image(for: author) {
+				return image
+			}
+		}
+		
+		if let authors = webFeed?.authors, authors.count == 1, let author = authors.first {
+			if let image = appDelegate.authorAvatarDownloader.image(for: author) {
+				return image
+			}
+		}
+
+		guard let webFeed = webFeed else {
+			return nil
+		}
+		
+		let feedIconImage = appDelegate.webFeedIconDownloader.icon(for: webFeed)
+		if feedIconImage != nil {
+			return feedIconImage
+		}
+		
+		if let faviconImage = appDelegate.faviconDownloader.faviconAsIcon(for: webFeed) {
+			return faviconImage
+		}
+		
+		return FaviconGenerator.favicon(webFeed)
+	}
+	
+	func byline() -> String {
+		guard let authors = authors ?? webFeed?.authors, !authors.isEmpty else {
+			return ""
+		}
+
+		// If the author's name is the same as the feed, then we don't want to display it.
+		// This code assumes that multiple authors would never match the feed name so that
+		// if there feed owner has an article co-author all authors are given the byline.
+		if authors.count == 1, let author = authors.first {
+			if author.name == webFeed?.nameForDisplay {
+				return ""
+			}
+		}
+		
+		var byline = ""
+		var isFirstAuthor = true
+
+		for author in authors {
+			if !isFirstAuthor {
+				byline += ", "
+			}
+			isFirstAuthor = false
+
+			if let emailAddress = author.emailAddress, emailAddress.contains(" ") {
+				byline += emailAddress // probably name plus email address
+			}
+			else if let name = author.name, let emailAddress = author.emailAddress {
+				byline += "\(name) <\(emailAddress)>"
+			}
+			else if let name = author.name {
+				byline += name
+			}
+			else if let emailAddress = author.emailAddress {
+				byline += "<\(emailAddress)>"
+			}
+			else if let url = author.url {
+				byline += url
+			}
+		}
+
+		return byline
+	}
+	
+}
+
+// MARK: Path
+
+struct ArticlePathKey {
+	static let accountID = "accountID"
+	static let accountName = "accountName"
+	static let webFeedID = "webFeedID"
+	static let articleID = "articleID"
+}
+
+extension Article {
+
+	public var pathUserInfo: [AnyHashable : Any] {
+		return [
+			ArticlePathKey.accountID: accountID,
+			ArticlePathKey.accountName: account?.nameForDisplay ?? "",
+			ArticlePathKey.webFeedID: webFeedID,
+			ArticlePathKey.articleID: articleID
+		]
+	}
+
+}
+
+// MARK: SortableArticle
+
+extension Article: SortableArticle {
+	
+	var sortableName: String {
+		return webFeed?.name ?? ""
+	}
+	
+	var sortableDate: Date {
+		return logicalDatePublished
+	}
+	
+	var sortableArticleID: String {
+		return articleID
+	}
+	
+	var sortableWebFeedID: String {
+		return webFeedID
+	}
+	
+}