Add ignored state for pages

Sources/Generator/Content/Element.swift

@@ -240,6 +240,10 @@ struct Element {
         guard let metadata = GenericMetadata(source: source, log: log) else {
             return nil
         }
+        let state: PageState = log.cast(metadata.state, "state", source: source)
+        guard state != .ignored else {
+            return nil
+        }
 
         var isValid = true
 
@@ -248,7 +252,7 @@ struct Element {
         self.topBarTitle = log.unused(metadata.topBarTitle, "topBarTitle", source: source)
         self.date = metadata.date.unwrapped { log.cast($0, "date", source: source) }
         self.endDate = metadata.endDate.unwrapped { log.cast($0, "endDate", source: source) }
-        self.state = log.cast(metadata.state, "state", source: source)
+        self.state = state
         self.sortIndex = metadata.sortIndex
         // TODO: Propagate external files from the parent if subpath matches?
         self.externalFiles = Element.rootPaths(for: metadata.externalFiles, path: path)

Sources/Generator/Content/PageState.swift

@@ -15,6 +15,11 @@ enum PageState: String {
      Generate the page, but don't include it in overviews of the parent.
      */
     case hidden
+
+    /**
+     Completely ignore the element.
+     */
+    case ignored
 }
 
 extension PageState {
@@ -23,7 +28,7 @@ extension PageState {
         switch self {
         case .standard, .draft:
             return true
-        case .hidden:
+        case .hidden, .ignored:
             return false
         }
     }
@@ -32,9 +37,7 @@ extension PageState {
         switch self {
         case .standard:
             return true
-        case .draft:
-            return false
-        case .hidden:
+        case .draft, .hidden, .ignored:
             return false
         }
     }
@@ -47,7 +50,7 @@ extension PageState: StringProperty {
     }
 
     static var castFailureReason: String {
-        "Page state must be 'standard', 'draft' or 'hidden'"
+        "Page state must be 'standard', 'draft', 'hidden', or 'ignored'"
     }
 }