Rework content commands, add audio player

CHDataManagement/Model/Content+Validation.swift

@@ -0,0 +1,28 @@
+import Foundation
+
+extension Content {
+
+    private static let disallowedCharactersInIds = CharacterSet.alphanumerics.union(CharacterSet(charactersIn: "-")).inverted
+
+    private static let disallowedCharactersInFileIds = CharacterSet.alphanumerics.union(CharacterSet(charactersIn: "-.")).inverted
+
+    func isNewIdForTag(_ id: String) -> Bool {
+        !tags.contains { $0.id == id }
+    }
+
+    func isNewIdForPage(_ id: String) -> Bool {
+        !pages.contains { $0.id == id }
+    }
+
+    func isNewIdForPost(_ id: String) -> Bool {
+        !posts.contains { $0.id == id }
+    }
+
+    func isValidIdForTagOrTagOrPost(_ id: String) -> Bool {
+        id.rangeOfCharacter(from: Content.disallowedCharactersInIds) == nil
+    }
+
+    func isValidIdForFile(_ id: String) -> Bool {
+        id.rangeOfCharacter(from: Content.disallowedCharactersInFileIds) == nil
+    }
+}