Added a ReadLine overload that validates the entered string and retur…

…ns it if it's valid.

ExtendedConsole/ExConsoleRead.cs

@@ -99,6 +99,46 @@ public static string ReadLine(this ExConsole self, string title)
             return Console.ReadLine();
         }
 
+        /// <summary>
+        /// Writes the title to the console, reads a line of text, 
+        /// and returns the input only if it passed the validataion.
+        /// </summary>
+        /// <param name="self">The current instance of ExConsole.</param>
+        /// <param name="title">The title to show the user before asking for input.</param>
+        /// <param name="errorMessage">The error message to show the user if the validation failed.</param>
+        /// <param name="validator">The <see cref="Predicate{T}"/> to validate the input with.</param>
+        /// <returns>The string the user entered.</returns>
+        /// <exception cref="ArgumentNullException">Thrown when <paramref name="self"/> or <paramref name="title"/> are null.</exception>
+        /// <exception cref="ArgumentException">Thrown when <paramref name="title"/> is empty.</exception>
+        /// <exception cref="System.Xml.XmlException">Thrown when <paramref name="title"/> isn't properly formatted xml.</exception>
+        /// <example>
+        /// Write "Please enter your first name:" to the console, where "first" is in green,
+        /// waits for the user to enter a lime, and returns the user's input.
+        /// <code>
+        /// var firstName = exConsole.ReadLine("Please enter your &lt;c f='green'&gt;first&lt;/c&gt; name:", "&lt;c f='green'&gt;first&lt;/c&gt; name must start with a capital letter", s => char.IsUpper(s[0]));
+        /// </code>
+        /// </example>
+        public static string ReadLine(this ExConsole self, string title, string errorMessage, Predicate<string> validator)
+        {
+            if (self is null) throw new ArgumentNullException(nameof(self));
+            if (title is null) throw new ArgumentNullException(nameof(title));
+            if (title == "") throw new ArgumentException(nameof(title) + " can't be empty.", nameof(title));
+            if (errorMessage is null) throw new ArgumentNullException(nameof(errorMessage));
+            if (errorMessage == "") throw new ArgumentException(nameof(errorMessage) + " can't be empty.", nameof(errorMessage));
+            if (validator is null) throw new ArgumentNullException(nameof(title));
+
+            self.WriteLine(title);
+            while (true)
+            {
+                var input = Console.ReadLine();
+                if (validator(input))
+                {
+                    return input;
+                }
+                self.WriteLine(errorMessage);
+            }
+        }
+
         /// <summary>
         /// Reads an input line from the user and converts it to T.
         /// Repeats until conversion succeeds (even if the user entered ^Z).

ExtendedConsole/ExtendedConsole.csproj

@@ -12,13 +12,11 @@
     <Copyright />
     <GeneratePackageOnBuild>true</GeneratePackageOnBuild>
     <LangVersion>7.3</LangVersion>
-    <PackageReleaseNotes>Changes from previous version:
-1. Fixed a bug in multiple select menu that caused flickering with large menus.
-2. Added a property to MultipleSelectDisplayArgs to control the forecolor of the selected Item(s)
-3. Removed obsolte methods from menus
-4. Marked a couple of methos as obsolte
-5. Added a ReadKey extension method</PackageReleaseNotes>
-    <Version>2.0.0</Version>
+    <PackageReleaseNotes>
+		Changes from previous version:
+		1. Added a ReadLine overload that validates the entered string and returns it if it's valud
+	</PackageReleaseNotes>
+    <Version>2.1.0</Version>
     <PackageIconUrl>https://raw.githubusercontent.com/Peled-Zohar/ExtendedConsole/master/ExtendedConsole.png</PackageIconUrl>
     <ApplicationIcon>extendedconsole.ico</ApplicationIcon>
   </PropertyGroup>

UsingExtendedConsole/Program.cs

@@ -45,7 +45,8 @@ private static int StringsMenu()
                 "Read DateTime",
                 "Read int",
                 "Clear lines",
-                "Try it yourself"
+                "Try it yourself",
+                "Read validated string"
             );
 
             switch (result)
@@ -68,6 +69,9 @@ private static int StringsMenu()
                 case 6:
                     TryItYourself();
                     break;
+                case 7:
+                    ReadValidatedString();
+                    break;
             }
             return result;
         }
@@ -80,7 +84,8 @@ private static int ActionsMenu()
                 ("Read DateTime", ReadDateTimeMethods),
                 ("Read int", ReadIntMethods),
                 ("Clear lines", ClearLines),
-                ("Try it yourself", TryItYourself)
+                ("Try it yourself", TryItYourself),
+                ("Read validated string", ReadValidatedString)
             );
 
         static void WriteLineMethods()
@@ -168,6 +173,13 @@ private static void MultipleSelectMenus()
 
             var b = exConsole.MultipleSelectMenu(new MultipleSelectDisplayArgs("Multiple select with args and toString"), s => $"<c f='green'>{s.Id}</c> {s.Name}", arr);
         }
+
+        private static void ReadValidatedString()
+        {
+            var line = exConsole.ReadLine("Enter a string that <c f='green'>starts with a digit</c>", "<c f='red'>invalid string entered</c>", s => char.IsDigit(s[0]));
+            exConsole.WriteLine($"You've entered: <c f='green'>{line}</c>");
+            exConsole.Pause(); 
+        }
     }
 
     public class MID