Got at least one data fetching method working; turns out, we can't use a patched LogicStack to get the data

Vendor/Swan.Lite-3.1.0/Validators/Validators.cs

@@ -0,0 +1,132 @@
+using System;
+using System.Text.RegularExpressions;
+
+namespace Swan.Validators
+{
+    /// <summary>
+    /// Regex validator.
+    /// </summary>
+    [AttributeUsage(AttributeTargets.Property)]
+    public class MatchAttribute : Attribute, IValidator
+    {
+        /// <summary>
+        /// Initializes a new instance of the <see cref="MatchAttribute" /> class.
+        /// </summary>
+        /// <param name="regex">A regex string.</param>
+        /// <param name="errorMessage">The error message.</param>
+        /// <exception cref="ArgumentNullException">Expression.</exception>
+        public MatchAttribute(string regex, string? errorMessage = null)
+        {
+            Expression = regex ?? throw new ArgumentNullException(nameof(regex));
+            ErrorMessage = errorMessage ?? "String does not match the specified regular expression";
+        }
+
+        /// <summary>
+        /// The string regex used to find a match.
+        /// </summary>
+        public string Expression { get; }
+
+        /// <inheritdoc/>
+        public string ErrorMessage { get; internal set; }
+
+        /// <inheritdoc/>
+        public bool IsValid<T>(T value)
+        {
+            if (Equals(value, default(T)))
+                return false;
+
+            return !(value is string)
+                ? throw new ArgumentException("Property is not a string")
+                : Regex.IsMatch(value.ToString(), Expression);
+        }
+    }
+
+    /// <summary>
+    /// Email validator.
+    /// </summary>
+    [AttributeUsage(AttributeTargets.Property)]
+    public class EmailAttribute : MatchAttribute
+    {
+        private const string EmailRegExp =
+            @"^(?("")("".+?(?<!\\)""@)|(([0-9a-z]((\.(?!\.))|[-!#\$%&'\*\+/=\?\^`\{\}\|~\w])*)(?<=[0-9a-z])@))" +
+            @"(?(\[)(\[(\d{1,3}\.){3}\d{1,3}\])|(([0-9a-z][-0-9a-z]*[0-9a-z]*\.)+[a-z0-9][\-a-z0-9]{0,22}[a-z0-9]))$";
+
+        /// <summary>
+        /// Initializes a new instance of the <see cref="EmailAttribute"/> class.
+        /// </summary>
+        /// <param name="errorMessage">The error message.</param>
+        public EmailAttribute(string? errorMessage = null)
+            : base(EmailRegExp, errorMessage ?? "String is not an email")
+        {
+        }
+    }
+
+    /// <summary>
+    /// A not null validator.
+    /// </summary>
+    [AttributeUsage(AttributeTargets.Property)]
+    public class NotNullAttribute : Attribute, IValidator
+    {
+        /// <inheritdoc/>
+        public string ErrorMessage => "Value is null";
+
+        /// <inheritdoc/>
+        public bool IsValid<T>(T value) => !Equals(default(T), value);
+    }
+
+    /// <summary>
+    /// A range constraint validator.
+    /// </summary>
+    [AttributeUsage(AttributeTargets.Property)]
+    public class RangeAttribute : Attribute, IValidator
+    {
+        /// <summary>
+        /// Initializes a new instance of the <see cref="RangeAttribute"/> class.
+        /// Constructor that takes integer minimum and maximum values.
+        /// </summary>
+        /// <param name="min">The minimum value.</param>
+        /// <param name="max">The maximum value.</param>
+        public RangeAttribute(int min, int max)
+        {
+            if (min >= max)
+                throw new InvalidOperationException("Maximum value must be greater than minimum");
+
+            Maximum = max;
+            Minimum = min;
+        }
+
+        /// <summary>
+        /// Initializes a new instance of the <see cref="RangeAttribute"/> class.
+        /// Constructor that takes double minimum and maximum values.
+        /// </summary>
+        /// <param name="min">The minimum value.</param>
+        /// <param name="max">The maximum value.</param>
+        public RangeAttribute(double min, double max)
+        {
+            if (min >= max)
+                throw new InvalidOperationException("Maximum value must be greater than minimum");
+
+            Maximum = max;
+            Minimum = min;
+        }
+
+        /// <inheritdoc/>
+        public string ErrorMessage => "Value is not within the specified range";
+
+        /// <summary>
+        /// Maximum value for the range.
+        /// </summary>
+        public IComparable Maximum { get; }
+
+        /// <summary>
+        /// Minimum value for the range.
+        /// </summary>
+        public IComparable Minimum { get; }
+
+        /// <inheritdoc/>
+        public bool IsValid<T>(T value)
+            => value is IComparable comparable
+            ? comparable.CompareTo(Minimum) >= 0 && comparable.CompareTo(Maximum) <= 0
+            : throw new ArgumentException(nameof(value));
+    }
+}