Show source of missing page links

CHDataManagement/Generator/Results/GenerationResults.swift

@@ -260,6 +260,18 @@ final class GenerationResults: ObservableObject {
         let unused = existingFiles.subtracting(outputFiles)
         update { self.unusedFilesInOutput = unused }
     }
+
+    func sources(forMissingPage page: String) -> [(page: LocalizedItemId, source: String)] {
+        var all = [(page: LocalizedItemId, source: String)]()
+        for (id, results) in cache {
+            guard let sources = results.missingLinkedPages[page]?.sorted() else {
+                continue
+            }
+            let additions = sources.map { (page: id, source: $0) }
+            all.append(contentsOf: additions)
+        }
+        return all
+    }
 }
 
 private extension Dictionary where Value == Set<LocalizedItemId> {

CHDataManagement/Model/Item/LocalizedItemId.swift

@@ -31,3 +31,10 @@ extension LocalizedItemId: Comparable {
         return lhs.language < rhs.language
     }
 }
+
+extension LocalizedItemId: CustomStringConvertible {
+
+    var description: String {
+        "\(itemType) (\(language))"
+    }
+}

CHDataManagement/Views/Generation/GenerationContentView.swift

@@ -110,7 +110,13 @@ struct GenerationContentView: View {
                 items: content.results.missingTags)
             GenerationStringIssuesView(
                 text: "missing pages",
-                items: content.results.missingPages)
+                items: content.results.missingPages) { pageId in
+                    let sources = content.results.sources(forMissingPage: pageId)
+                        .map { "\($0.page): \($0.source)"}
+                        .joined(separator: ", ")
+
+                    return "\(pageId) (\(sources))"
+                }
             GenerationStringIssuesView(
                 text: "invalid commands",
                 items: content.results.invalidCommands)