Created FileList with ability to set used files

HaDocumentNew/Settings/XMLRoots/MarginalsRoot.cs

@@ -0,0 +1,49 @@
+namespace HaDocument.Settings.XMLRoots;
+using System.Xml.Linq;
+
+public class MarginalsRoot : HaWeb.XMLParser.IXMLRoot {
+    public string Type { get; } = "Stellenkommentar";
+    public string Prefix { get; } = "stellenkommentar";
+    public string[] XPathContainer { get; } = { ".//data/marginalien", ".//marginalien" };
+
+    public Predicate<XElement> IsCollectedObject { get; } = (elem) => {
+        if (elem.Name == "marginal") return true;
+        else return false;
+    };
+
+    public Func<XElement, string?> GetKey { get; } = (elem) => {
+        var index = elem.Attribute("index");
+        if (index != null && !String.IsNullOrWhiteSpace(index.Value))
+            return index.Value;
+        else return null;
+    };
+
+    public List<(string, string?)>? GenerateFields(XMLRootDocument document) {
+        return null;
+    }
+
+    public (string?, string?) GenerateIdentificationString(XElement element) {
+        return (null, null);
+    }
+
+    public bool Replaces(XMLRootDocument doc1, XMLRootDocument doc2) {
+        return true;
+    }
+
+    public XElement CreateHamannDocument(XElement element) {
+        var opus = new XElement("opus");
+        opus.AddFirst(element);
+        return opus;
+    }
+
+    public void MergeIntoFile(XElement file, XMLRootDocument document) {
+        if (file.Element("marginalien") == null)
+            file.AddFirst(new XElement("marginalien"));
+        var elements = document.Root.Elements().Where(x => IsCollectedObject(x));
+        var root = file.Element("marginalien");
+        foreach (var element in elements) {
+            root!.Add(element);
+        }
+    }
+
+}