Improve header handling for post lists

CHDataManagement/Generator/HeaderElement.swift

@@ -95,7 +95,10 @@ extension HeaderElement: Hashable {
 extension HeaderElement: Comparable {
 
     static func < (lhs: HeaderElement, rhs: HeaderElement) -> Bool {
-        lhs.order < rhs.order
+        guard lhs.order == rhs.order else {
+            return lhs.order < rhs.order
+        }
+        return lhs.content < rhs.content
     }
 }
 

CHDataManagement/Generator/Page Generators/FeedPageGenerator.swift

@@ -11,15 +11,16 @@ final class FeedPageGenerator {
         self.results = results
     }
 
-    private func includeSwiper(in headers: inout Set<HeaderElement>) {
-        if let swiperCss = content.settings.posts.swiperCssFile {
-            headers.insert(.css(file: swiperCss, order: HeaderElement.swiperCssFileOrder))
-            results.require(file: swiperCss)
-        }
-        if let swiperJs = content.settings.posts.swiperJsFile {
-            headers.insert(.js(file: swiperJs, defer: true))
-            results.require(file: swiperJs)
+    private func makeHeaders(requiredItems: Set<KnownHeaderElement>, results: PageGenerationResults) -> Set<HeaderElement> {
+        var result = content.postPageHeaders
+        for item in requiredItems {
+            guard let header = item.header(content: content) else {
+                results.warning("Header \(item) not configured in settings")
+                continue
+            }
+            result.insert(header)
         }
+        return result
     }
 
     func generatePage(language: ContentLanguage,
@@ -33,13 +34,16 @@ final class FeedPageGenerator {
                       totalPages: Int,
                       languageButtonUrl: String,
                       linkPrefix: String) -> String {
-        var headers = content.postPageHeaders
         var footer = ""
+        var requiredHeaders = Set<KnownHeaderElement>()
         if posts.contains(where: { $0.requiresSwiper }) {
             // Sort swiper style sheet before default style sheet
-            includeSwiper(in: &headers)
+            requiredHeaders.formUnion([.swiperJs, .swiperCss])
             footer = swiperInitScript(posts: posts)
         }
+        let headers = makeHeaders(requiredItems: requiredHeaders, results: results)
+        results.require(files: headers.compactMap { $0.requiredFile })
+        results.require(headers: requiredHeaders)
 
         let iconUrl = content.settings.navigation.localized(in: language).rootUrl
         let languageButton = NavigationBar.Link(

CHDataManagement/Generator/Post Lists/PostListPageGenerator.swift

@@ -116,6 +116,8 @@ final class PostListPageGenerator {
         // Includes leading slash
         let pageUrl = pageUrl(in: language, pageNumber: pageIndex)
 
+        #warning("Use results for each individual posts page")
+
         let fileContent = feedPageGenerator.generatePage(
             language: language,
             posts: posts,

CHDataManagement/Generator/Results/PageGenerationResults.swift

@@ -242,6 +242,10 @@ final class PageGenerationResults: ObservableObject {
         onMain { self.requiredHeaders.formUnion(headers) }
     }
 
+    func require<S>(headers: S) where S: Sequence, S.Element == KnownHeaderElement {
+        onMain { self.requiredHeaders.formUnion(headers) }
+    }
+
     func require(icon: PageIcon) {
         onMain { self.requiredIcons.insert(icon) }
     }