/Trunk/WebConfigModifier/WebConfigUpdater.cs

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Xml.Linq;

using System.IO;

using System.Xml;

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;



namespace WebConfigModifier

{

    public class WebConfigUpdater

    {

        public void HandleRequest(Stack<string> argStack, string value)

        {

            try

            {

                if (argStack == null) throw new ArgumentNullException("argStack");

                if (argStack.Count < 3) throw new ArgumentException();



                if (value == null) throw new ArgumentNullException("value");



                string webConfigFileName = argStack.Pop();

                string action = argStack.Pop();

                string xPathExpression = argStack.Pop();



                UpdateWebConfig(argStack, value, webConfigFileName, action, xPathExpression);

            }

            catch (ArgumentException exc)

            {

                Console.WriteLine(exc.Message);

                Console.WriteLine();

                DisplayUsage();

                throw new UsageException("Incorrect usage.", exc);

            }

            catch (UsageException exc)

            {

                Console.WriteLine(exc.Message);

                Console.WriteLine();

                DisplayUsage();

                throw;

            }

            catch (Exception exc)

            {

                Console.WriteLine(exc.Message);

                throw;

            }

        }



        private static void UpdateWebConfig(Stack<string> argStack, string value, string webConfigFileName, string action, string xPathExpression)

        {

            XDocument doc = LoadWebConfig(webConfigFileName);



            DocumentModifier modifier = new DocumentModifier(doc);



            if (action == "/element")

            {

                modifier.ReplaceElementValue(xPathExpression, value);

            }

            else if (action == "/attribute")

            {

                if (!argStack.Any()) throw new UsageException();

                string attributeName = argStack.Pop();



                modifier.ReplaceAttributeValue(xPathExpression, attributeName, value);

            }

            else

            {

                throw new UsageException(string.Format("Unknown action '{0}'", action));

            }



            SaveWebConfig(webConfigFileName, doc);

        }



        private static XDocument LoadWebConfig(string webConfigFileName)

        {

            string xml = File.ReadAllText(webConfigFileName);

            XDocument doc = XDocument.Parse(xml);

            return doc;

        }



        private static void SaveWebConfig(string webConfigFileName, XDocument doc)

        {

            XmlWriterSettings settings = new XmlWriterSettings

            {

                Indent = true,

                NewLineChars = Environment.NewLine,

                NewLineHandling = System.Xml.NewLineHandling.Replace,

                NewLineOnAttributes = false,

            };

            using (var writer = XmlWriter.Create(webConfigFileName, settings))

            {

                doc.WriteTo(writer);

            }

        }



        private static bool ParseCommandLineArguments(string[] args, out string webConfigFilename, out string action, out string key)

        {

            webConfigFilename = null;

            action = null;

            key = null;

            if (args.Length != 3) return false;



            webConfigFilename = args[0];

            action = args[1];

            key = args[2];

            return true;

        }



        private static void DisplayUsage()

        {

            Console.WriteLine("usage:");

            Console.WriteLine("  echo <value> | WebConfigModifier.exe <path to web.config> /element <xPathToElement>");

            Console.WriteLine("  type <filename> | WebConfigModifier.exe <path to web.config> /element <xPathToElement>");

            Console.WriteLine("  echo <value> | WebConfigModifier.exe <path to web.config> /attribute <xPathToElement> <attributeName>");

            Console.WriteLine();

            Console.WriteLine("e.g.:");

            Console.WriteLine();

            Console.WriteLine("  To replace individual connection strings, replace the providerName and connectionString attributes:");

            Console.WriteLine("    echo System.Data.SqlClient | WebConfigModifier.exe Samples\\Mvc2.Vanilla.Web.config /attribute /configuration/connectionStrings/add[@name='ApplicationServices'] providerName");

            Console.WriteLine("    echo \"data source=.\\SQLEXPRESS;Integrated Security=SSPI;AttachDBFilename=|DataDirectory|different_aspnetdb.mdf;User Instance=true\" | WebConfigModifier.exe Samples\\Mvc2.Vanilla.Web.config /attribute /configuration/connectionStrings/add[@name='ApplicationServices'] connectionString");

            Console.WriteLine();

            Console.WriteLine("  To replace the entire connectionStrings document element from a file:");

            Console.WriteLine("    type Samples\\connectionStrings.xml | WebConfigModifier.exe Samples\\Mvc2.Vanilla.Web.config /element /configuration/connectionStrings");

        }

    }

}