QueryWindow: Allow users to export query result to csv file

Elwig/Helpers/Export/Csv.cs

@@ -15,7 +15,9 @@ namespace Elwig.Helpers.Export {
         protected readonly char Separator;
         protected string? Header;
 
-        public Csv(string filename, char separator = ';') : this(filename, separator, Utils.UTF8) { }
+        public Csv(string filename, char separator = ';') :
+            this(filename, separator, Utils.UTF8) {
+        }
 
         public Csv(string filename, char separator, Encoding encoding) {
             _writer = new StreamWriter(filename, false, encoding);
@@ -58,4 +60,22 @@ namespace Elwig.Helpers.Export {
 
         public abstract string FormatRow(T row);
     }
+
+    public class CsvSimple : Csv<IEnumerable<object?>> {
+
+        public CsvSimple(string filename, char separator, Encoding encoding) :
+            base(filename, separator, encoding) {
+        }
+
+        public CsvSimple(string filename, char separator = ';') :
+            base(filename, separator) {
+        }
+
+        public override string FormatRow(IEnumerable<object?> row) {
+            return string.Join(Separator, row.Select(i => {
+                var str = $"{i}";
+                return str.Contains(Separator) || str.Contains('\n') ? $"\"{str.Replace("\"", "\"\"")}\"" : str;
+            }));
+        }
+    }
 }

Elwig/Helpers/Utils.cs

@@ -36,6 +36,7 @@ namespace Elwig.Helpers {
     public static partial class Utils {
 
         public static readonly Encoding UTF8 = new UTF8Encoding(false, true);
+        public static readonly Encoding UTF8BOM = new UTF8Encoding(true, true);
         public static readonly JsonSerializerOptions JsonOpts = new() { Encoder = System.Text.Encodings.Web.JavaScriptEncoder.UnsafeRelaxedJsonEscaping };
 
         public static int CurrentYear => DateTime.Now.Year;