Generate list of redirects

CHDataManagement/Generator/Results/GenerationResults.swift

@@ -46,6 +46,15 @@ final class GenerationResults: ObservableObject {
     @Published
     var emptyPages: Set<LocalizedPageId> = []
 
+    /**
+     The url redirects to install to prevent broken links.
+
+     The key is the original url, and the value the new url of the content, relative to the output folder.
+     The dictionary is used to create a map of redirects for Nginx.
+     */
+    @Published
+    var redirects: [String : String] = [:]
+
     /// The cache of previously used GenerationResults
     private var cache: [ItemId : PageGenerationResults] = [:]
 
@@ -114,6 +123,8 @@ final class GenerationResults: ObservableObject {
         update { self.warnings = warnings }
         let unsavedOutputFiles = cache.values.map { $0.unsavedOutputFiles.keys }.union()
         update { self.unsavedOutputFiles = unsavedOutputFiles }
+        let redirects = cache.values.compactMap { $0.redirect }.reduce(into: [:]) { $0[$1.originalUrl] = $1.newUrl }
+        update { self.redirects = redirects }
     }
 
     private func update(_ operation: @escaping () -> Void) {
@@ -185,7 +196,11 @@ final class GenerationResults: ObservableObject {
     }
 
     func empty(_ page: LocalizedPageId) {
-        update {self.emptyPages.insert(page) }
+        update { self.emptyPages.insert(page) }
+    }
+
+    func redirect(from originalUrl: String, to newUrl: String) {
+        update { self.redirects[originalUrl] = newUrl }
     }
 }
 

CHDataManagement/Generator/Results/PageGenerationResults.swift

@@ -77,6 +77,8 @@ final class PageGenerationResults: ObservableObject {
 
     private(set) var pageIsEmpty: Bool
 
+    private(set) var redirect: (originalUrl: String, newUrl: String)?
+
     init(itemId: ItemId, delegate: GenerationResults) {
         self.itemId = itemId
         self.delegate = delegate
@@ -100,6 +102,7 @@ final class PageGenerationResults: ObservableObject {
         warnings = []
         unsavedOutputFiles = [:]
         pageIsEmpty = false
+        redirect = nil
     }
 
     func reset() {
@@ -123,6 +126,7 @@ final class PageGenerationResults: ObservableObject {
         warnings = []
         unsavedOutputFiles = [:]
         pageIsEmpty = false
+        redirect = nil
     }
 
     // MARK: Adding entries
@@ -251,5 +255,10 @@ final class PageGenerationResults: ObservableObject {
         pageIsEmpty = true
         delegate.empty(.init(language: itemId.language, pageId: page.id))
     }
+
+    func redirect(from originalUrl: String, to newUrl: String) {
+        redirect = (originalUrl, newUrl)
+        delegate.redirect(from: originalUrl, to: newUrl)
+    }
 }