Apply XSL transformation on XML - VB.net

using System;
using System.Text.RegularExpressions;
using Altova.AltovaXML;

namespace RedCell.App.XsltTransformer
{
    /// <summary>
    /// Transformer does the work of transforming input into output using XSLT.
    /// </summary>
    public class Transformer
    {
        #region Initialization
        /// <summary>
        /// Initializes a new instance of the <see cref="Transformer"/> class.
        /// </summary>
        public Transformer()
        {
            this.Input = "";
            this.Xslt = "";
            this.Output = "";
        }

        /// <summary>
        /// Initializes a new instance of the <see cref="Transformer"/> class.
        /// </summary>
        /// <param name="input">The input.</param>
        /// <param name="xslt">The XSLT.</param>
        public Transformer(string input, string xslt)
        {
            this.Input = input;
            this.Xslt = xslt;
        }
        #endregion

        #region Properties
        /// <summary>
        /// Gets or sets the input.
        /// </summary>
        /// <value>The input.</value>
        public string Input { get; set; }

        /// <summary>
        /// Gets or sets the XSLT.
        /// </summary>
        /// <value>The XSLT.</value>
        public string Xslt { get; set; }

        /// <summary>
        /// Gets or sets the output.
        /// </summary>
        /// <value>The output.</value>
        public string Output { get; set; }
        #endregion

        #region Methods
        /// <summary>
        /// Transforms this instance.
        /// </summary>
        public void Transform()
        {
            // Sanity checks
            if(string.IsNullOrEmpty(Input))
                throw new ArgumentNullException("Entrée");
            if (string.IsNullOrEmpty(Xslt))
                throw new ArgumentNullException("Xslt");

            // Strip the DTD from the input.
            Input = Regex.Replace(Input, "<!DOCTYPE.+?>", "", RegexOptions.Singleline);

            // Transform!
            var app = new ApplicationClass();
            XSLT2 xslt2 = app.XSLT2;
            xslt2.XSLFromText = Xslt;
            xslt2.InputXMLFromText = Input;
            Output = xslt2.ExecuteAndGetResultAsString();
        }
        #endregion
    }
}