Application Configuration Editor using the PropertyGrid

using System;
using System.Drawing;
using System.Collections;
using System.ComponentModel;
using System.Windows.Forms;
using System.Xml;

namespace DotBits.Configuration
{
	/// <summary>
	/// The application will be compiled both as a .DLL and a .EXE. The DLL can be referenced
	/// by other Windows Forms applications and used to instantiate the ConfigEditor form. 
	/// If ConfigEditor is called from the DLL - static void Main(string[] args) will not
	/// be called - in which case the constructor will determine the configuration
	/// filename.
	/// 
	/// If the .EXE is called - optional args can be supplied to specify the Xml configuration
	/// file to use.
	/// 
	/// Configuration Loading and Saving methods have been kept clean from the interface
	/// event handlers. Compiled as a .DLL these methods could be called from an administrative
	/// ASP.Net Web Form which would could add text controls dynamically to the page to build a
	/// Web Form that contains all the key value pairs for all the properties in the custom
	/// class - allowing the configuration of the Web application to be set or changed remotely.
	/// </summary>		
	public class ConfigEditor : System.Windows.Forms.Form
	{

		#region Variables, Properties and Controls

		//private data
		private string _configFilename = "";
		private bool _isDirty;
		private bool IsDirty
		{
			get { return _isDirty;}
			set { _isDirty = value;}
		}		
		
		//public properties
		public virtual string ConfigFilename
		{
			get 
			{ 
				return _configFilename;
			}
			set 
			{ 
				_configFilename = value;
				this.txtConfigurationFile.Text = _configFilename;
			}
		}
		
		//Controls
		private System.Windows.Forms.Button btnSave;
		private System.Windows.Forms.Button btnClose;
		private System.Windows.Forms.TextBox txtConfigurationFile;
		private System.Windows.Forms.PropertyGrid propertyGrid1;
		private System.Windows.Forms.Button btnLoad;
		private System.Windows.Forms.OpenFileDialog openFileDialog1;
		private System.Windows.Forms.GroupBox groupBox1;
		private System.Windows.Forms.Label lblTitle;
		private System.Windows.Forms.PictureBox pictureBox1;		
		
		/// <summary>
		/// Required designer variable.
		/// </summary>
		private System.ComponentModel.Container components = null;

		#endregion
		
		/// <summary>
		/// If called from static void Main(string[] args) during a .EXE startup, 
		/// then the the value of this.ConfigFilename may be overwritten by an optional 
		/// argument passed to Main.
		/// </summary>
		public ConfigEditor()
		{
			//
			// Required for Windows Form Designer support
			//
			InitializeComponent();		
						
			//Set the configuration file value based on a couple of rules.
			//If Bin is the last directory in the Executable path, then it's in a 
			//Web/Bin directory and we'll load Web.config from the directory above. 
			//If not, then we'll look for a configuration file in the executable
			//directory *.Config (if for some reason there is more than one - which there
			//shoudn't be - we'll take the first one).
			//If we're being called from Main(string[] args) and a parameter was 
			//passed then this value will be replaced when Main(string[] args) completes.
			string dir = System.IO.Path.GetDirectoryName(Application.ExecutablePath);
			if (dir.LastIndexOf("\\bin") == dir.Length - 4)
			{
				//\Bin is at the end of the directory path and the application has been called
				//from a Web project folder.
				this.ConfigFilename = dir.Remove(dir.Length - 3, 3) + "Web.Config";
			}
			else
			{
				string[] configFiles = System.IO.Directory.GetFiles(dir, "*.Config");
				if (configFiles.Length > 0)
				{
					this.ConfigFilename = configFiles[0];
				}
				else
				{
					this.ConfigFilename = "";
				}
			}			
		}

		/// <summary>
		/// If the .EXE is called, optional args can be supplied to specify the Xml configuration
		/// file to use.
		/// </summary>
		[STAThread]
		static void Main(string[] args)
		{
			ConfigEditor frmConfig = new ConfigEditor();
			if(args.Length > 0)
			{
				frmConfig.ConfigFilename = args[0];								
			}			
			Application.Run(frmConfig);
		}

		#region Windows Form Designer generated code
		/// <summary>
		/// Required method for Designer support - do not modify
		/// the contents of this method with the code editor.
		/// </summary>
		private void InitializeComponent()
		{
			System.Resources.ResourceManager resources = new System.Resources.ResourceManager(typeof(ConfigEditor));
			this.btnSave = new System.Windows.Forms.Button();
			this.btnClose = new System.Windows.Forms.Button();
			this.txtConfigurationFile = new System.Windows.Forms.TextBox();
			this.propertyGrid1 = new System.Windows.Forms.PropertyGrid();
			this.btnLoad = new System.Windows.Forms.Button();
			this.openFileDialog1 = new System.Windows.Forms.OpenFileDialog();
			this.groupBox1 = new System.Windows.Forms.GroupBox();
			this.pictureBox1 = new System.Windows.Forms.PictureBox();
			this.lblTitle = new System.Windows.Forms.Label();
			this.groupBox1.SuspendLayout();
			this.SuspendLayout();
			// 
			// btnSave
			// 
			this.btnSave.Anchor = ((System.Windows.Forms.AnchorStyles)((System.Windows.Forms.AnchorStyles.Top | System.Windows.Forms.AnchorStyles.Right)));
			this.btnSave.Font = new System.Drawing.Font("Microsoft Sans Serif", 8.25F, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, ((System.Byte)(0)));
			this.btnSave.Location = new System.Drawing.Point(297, 385);
			this.btnSave.Name = "btnSave";
			this.btnSave.Size = new System.Drawing.Size(120, 24);
			this.btnSave.TabIndex = 1;
			this.btnSave.Text = "&Save Settings";
			this.btnSave.Click += new System.EventHandler(this.btnSave_Click);
			// 
			// btnClose
			// 
			this.btnClose.Anchor = ((System.Windows.Forms.AnchorStyles)((System.Windows.Forms.AnchorStyles.Top | System.Windows.Forms.AnchorStyles.Right)));
			this.btnClose.Font = new System.Drawing.Font("Microsoft Sans Serif", 8.25F, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, ((System.Byte)(0)));
			this.btnClose.ImageAlign = System.Drawing.ContentAlignment.MiddleRight;
			this.btnClose.Location = new System.Drawing.Point(425, 385);
			this.btnClose.Name = "btnClose";
			this.btnClose.Size = new System.Drawing.Size(64, 24);
			this.btnClose.TabIndex = 2;
			this.btnClose.Text = "&Done";
			this.btnClose.Click += new System.EventHandler(this.btnClose_Click);
			// 
			// txtConfigurationFile
			// 
			this.txtConfigurationFile.Anchor = ((System.Windows.Forms.AnchorStyles)(((System.Windows.Forms.AnchorStyles.Top | System.Windows.Forms.AnchorStyles.Left) 
				| System.Windows.Forms.AnchorStyles.Right)));
			this.txtConfigurationFile.Font = new System.Drawing.Font("Microsoft Sans Serif", 8.25F, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, ((System.Byte)(0)));
			this.txtConfigurationFile.Location = new System.Drawing.Point(7, 353);
			this.txtConfigurationFile.Name = "txtConfigurationFile";
			this.txtConfigurationFile.ReadOnly = true;
			this.txtConfigurationFile.Size = new System.Drawing.Size(450, 20);
			this.txtConfigurationFile.TabIndex = 16;
			this.txtConfigurationFile.Text = "";
			// 
			// propertyGrid1
			// 
			this.propertyGrid1.Anchor = ((System.Windows.Forms.AnchorStyles)(((System.Windows.Forms.AnchorStyles.Top | System.Windows.Forms.AnchorStyles.Left) 
				| System.Windows.Forms.AnchorStyles.Right)));
			this.propertyGrid1.CommandsVisibleIfAvailable = true;
			this.propertyGrid1.Font = new System.Drawing.Font("Microsoft Sans Serif", 8.25F, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, ((System.Byte)(0)));
			this.propertyGrid1.LargeButtons = false;
			this.propertyGrid1.LineColor = System.Drawing.SystemColors.ScrollBar;
			this.propertyGrid1.Location = new System.Drawing.Point(7, 49);
			this.propertyGrid1.Name = "propertyGrid1";
			this.propertyGrid1.PropertySort = System.Windows.Forms.PropertySort.Categorized;
			this.propertyGrid1.Size = new System.Drawing.Size(482, 296);
			this.propertyGrid1.TabIndex = 0;
			this.propertyGrid1.Text = "propertyGrid1";
			this.propertyGrid1.ToolbarVisible = false;
			this.propertyGrid1.ViewBackColor = System.Drawing.SystemColors.Window;
			this.propertyGrid1.ViewForeColor = System.Drawing.SystemColors.WindowText;
			this.propertyGrid1.PropertyValueChanged += new System.Windows.Forms.PropertyValueChangedEventHandler(this.propertyGrid1_PropertyValueChanged);
			// 
			// btnLoad
			// 
			this.btnLoad.Anchor = ((System.Windows.Forms.AnchorStyles)((System.Windows.Forms.AnchorStyles.Top | System.Windows.Forms.AnchorStyles.Right)));
			this.btnLoad.Location = new System.Drawing.Point(465, 353);
			this.btnLoad.Name = "btnLoad";
			this.btnLoad.Size = new System.Drawing.Size(24, 20);
			this.btnLoad.TabIndex = 17;
			this.btnLoad.Text = "...";
			this.btnLoad.Click += new System.EventHandler(this.btnLoad_Click);
			// 
			// groupBox1
			// 
			this.groupBox1.Anchor = ((System.Windows.Forms.AnchorStyles)(((System.Windows.Forms.AnchorStyles.Top | System.Windows.Forms.AnchorStyles.Left) 
				| System.Windows.Forms.AnchorStyles.Right)));
			this.groupBox1.BackColor = System.Drawing.Color.White;
			this.groupBox1.Controls.Add(this.pictureBox1);
			this.groupBox1.Controls.Add(this.lblTitle);
			this.groupBox1.Location = new System.Drawing.Point(-16, -24);
			this.groupBox1.Name = "groupBox1";
			this.groupBox1.Size = new System.Drawing.Size(528, 66);
			this.groupBox1.TabIndex = 18;
			this.groupBox1.TabStop = false;
			// 
			// pictureBox1
			// 
			this.pictureBox1.Anchor = ((System.Windows.Forms.AnchorStyles)((System.Windows.Forms.AnchorStyles.Top | System.Windows.Forms.AnchorStyles.Right)));
			this.pictureBox1.Image = ((System.Drawing.Image)(resources.GetObject("pictureBox1.Image")));
			this.pictureBox1.Location = new System.Drawing.Point(472, 28);
			this.pictureBox1.Name = "pictureBox1";
			this.pictureBox1.Size = new System.Drawing.Size(48, 31);
			this.pictureBox1.TabIndex = 1;
			this.pictureBox1.TabStop = false;
			// 
			// lblTitle
			// 
			this.lblTitle.Font = new System.Drawing.Font("Microsoft Sans Serif", 14F, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, ((System.Byte)(0)));
			this.lblTitle.Location = new System.Drawing.Point(32, 29);
			this.lblTitle.Name = "lblTitle";
			this.lblTitle.Size = new System.Drawing.Size(272, 29);
			this.lblTitle.TabIndex = 0;
			this.lblTitle.Text = "Application Settings";
			// 
			// ConfigEditor
			// 
			this.AutoScaleBaseSize = new System.Drawing.Size(5, 13);
			this.ClientSize = new System.Drawing.Size(498, 423);
			this.Controls.Add(this.groupBox1);
			this.Controls.Add(this.btnLoad);
			this.Controls.Add(this.propertyGrid1);
			this.Controls.Add(this.txtConfigurationFile);
			this.Controls.Add(this.btnClose);
			this.Controls.Add(this.btnSave);
			this.Font = new System.Drawing.Font("Microsoft Sans Serif", 8.25F, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, ((System.Byte)(0)));
			this.FormBorderStyle = System.Windows.Forms.FormBorderStyle.FixedSingle;
			this.Icon = ((System.Drawing.Icon)(resources.GetObject("$this.Icon")));
			this.MaximizeBox = false;
			this.Name = "ConfigEditor";
			this.SizeGripStyle = System.Windows.Forms.SizeGripStyle.Hide;
			this.StartPosition = System.Windows.Forms.FormStartPosition.CenterScreen;
			this.Text = "Application Configuration";
			this.Load += new System.EventHandler(this.ConfigEditor_Load);
			this.groupBox1.ResumeLayout(false);
			this.ResumeLayout(false);

		}
		#endregion

		#region Form Layout and Event Handlers
		/// <summary>
		/// On FormLoad event handler which will call the LoadConfiguration helper method.
		/// /// <param name="sender"></param>
		/// <param name="e"></param>
		private void ConfigEditor_Load(object sender, System.EventArgs e)
		{
			try
			{
				if (System.IO.File.Exists(this.ConfigFilename))
				{
					this.propertyGrid1.SelectedObject = LoadConfiguration(this.ConfigFilename);
					LayoutForm((CustomClass)this.propertyGrid1.SelectedObject);
				}
			}
			catch (Exception ex)
			{
				MessageBox.Show("Failed to load the configuration file. Reason(" + ex.Message + ")", "Application Configuration", MessageBoxButtons.OK, MessageBoxIcon.Warning);
			}
			this.propertyGrid1.Focus();
		}	


		/// <summary>
		/// Check the state of IsDirty before closing the form and prompt the
		/// user to save their changes if IsDirty == true.
		/// </summary>
		/// <param name="sender"></param>
		/// <param name="e"></param>
		private void btnClose_Click(object sender, System.EventArgs e)
		{
			if (this.IsDirty == true)
			{
				DialogResult result = MessageBox.Show("Save Application Configuration changes before closing?", "Application Configuration", MessageBoxButtons.YesNoCancel, MessageBoxIcon.Question);
				if (result == DialogResult.Yes)
				{
					try
					{
						SaveConfiguration(this.ConfigFilename, (CustomClass)this.propertyGrid1.SelectedObject);
						MessageBox.Show("Application Configuration changes have been saved.", "Application Configuration", MessageBoxButtons.OK, MessageBoxIcon.Information);
						this.Close();
					}
					catch(Exception ex)
					{
						MessageBox.Show("Failed to btnSave configuration. Reason(" + ex.Message + ")", "Application Configuration", MessageBoxButtons.OK, MessageBoxIcon.Warning);
					}					
				}
				else if (result == DialogResult.No)
				{
					this.Close();
				}
			}
			else
			{
				this.Close();
			}
		}

		/// <summary>
		/// Save the state of the property grid back to the Xml configuration file.
		/// </summary>
		/// <param name="sender"></param>
		/// <param name="e"></param>
		private void btnSave_Click(object sender, System.EventArgs e)
		{
			try
			{
				SaveConfiguration(this.ConfigFilename, (CustomClass)this.propertyGrid1.SelectedObject);
				MessageBox.Show("Application Configuration changes have been saved.", "Application Configuration", MessageBoxButtons.OK, MessageBoxIcon.Information);
				this.IsDirty = false;
				this.propertyGrid1.Focus();
			}
			catch(Exception ex)
			{
				MessageBox.Show("Failed to btnSave configuration. Reason(" + ex.Message + ")", "Application Configuration", MessageBoxButtons.OK, MessageBoxIcon.Warning);
			}
		}	

		
		/// <summary>
		/// Property value changed - set the IsDirty flag to true.
		/// </summary>
		private void propertyGrid1_PropertyValueChanged(object s, System.Windows.Forms.PropertyValueChangedEventArgs e)
		{
			this.IsDirty = true;
		}

		/// <summary>
		/// Load a selected configuration file.
		/// </summary>
		/// <param name="sender"></param>
		/// <param name="e"></param>
		private void btnLoad_Click(object sender, System.EventArgs e)
		{
			openFileDialog1.Filter = "Configuration Files (*.config)| *.config";
			DialogResult result = openFileDialog1.ShowDialog();
			if (result == DialogResult.OK)
			{
				this.ConfigFilename = openFileDialog1.FileName;				
				this.propertyGrid1.SelectedObject = LoadConfiguration(this.ConfigFilename);
				LayoutForm((CustomClass)this.propertyGrid1.SelectedObject);
				this.propertyGrid1.Focus();
			}
		}

		/// <summary>
		/// This method will look at the Maximum value of either a property name or it's
		/// value (which ever is greater) and adjust the width of the form accordingly.
		/// The Property Grid is set to Anchor Left, Top and Right so it will expand along
		/// with the form.
		/// </summary>
		/// <param name="customClass"></param>
		private void LayoutForm(CustomClass customClass)
		{
			//MaxLength is the number of characters. At our current
			//font size we need to allow for an acceptable multiplier in pixels.
			if (customClass.MaxLength > 95)
			{
				this.Width = 665;
			}
			else
			{
				this.Width = customClass.MaxLength  * 7;
			}
		}

		#endregion
		
		#region Configuration Loading and Saving Methods
		/// <summary>
		/// Load the Xml Configuration document and populate our CustomClass with a dynamic property
		/// for each of the supported configuration sections. We're only supporting three sections here.
		/// The default appSettings, plus our standard ApplicationConfiguration
		/// and CommonConfiguration section handlers. These handlers are derived from IConfigurationSectionHandler.
		/// They have extended support for the Description attribute in addition to the Key, Value 
		/// pair attributes in the Xml configuration file.
		/// This could easily be extended to include support for any section under the configuration
		/// section that has the <add key="value" value="value"/> structure (assuming you haven't written a
		/// completely new Xml structure for your custom configuration section).
		/// </summary>
		public CustomClass LoadConfiguration(string configurationFile)
		{
			CustomClass customClass = new CustomClass();
			try
			{
				XmlDocument xmlDoc = new XmlDocument();
				xmlDoc.Load(configurationFile);
				XmlNode configuration = xmlDoc.SelectSingleNode("configuration");
			
				//Build the node list
				XmlNodeList sectionList = configuration.ChildNodes;
				for(int y = 0; y <  sectionList.Count; y++)
				{
					XmlNodeList settingsList = xmlDoc.SelectNodes("configuration/" + sectionList[y].Name + "/add");
					if (settingsList.Count != 0 && settingsList != null)
					{
						//Add a property to customClass for each node found.				
						for(int i = 0; i <  settingsList.Count; i++)
						{					
							XmlAttribute atrribKey = settingsList[i].Attributes["key"];
							XmlAttribute attribValue = settingsList[i].Attributes["value"];					
							XmlAttribute attribDescription = settingsList[i].Attributes["description"];					
							if(atrribKey != null && attribValue != null)
							{
								//If there's no description for the key - assign the name to the description.
								//The description attribute is displayed below the name in the property grid.
								if (attribDescription == null)
								{
									attribDescription = atrribKey;
								}
								//We'll at least test to see if it's a boolean property and set the type here
								//to force the property grid to display a dropdown list of True or False.
								Type propType;
								if (attribValue.Value.ToLower() == "true" || attribValue.Value.ToLower() == "false")
								{
									propType = typeof(System.Boolean);
								}
								else
								{
									propType = typeof(System.String);
								}
								//Now add the property
								customClass.AddProperty(atrribKey.Value.ToString(), attribValue.Value.ToString(), 
									attribDescription.Value.ToString(), sectionList[y].Name, propType, false, false);
							}
						}
					}					
				}				
				xmlDoc = null;				
			}
			catch(Exception ex)
			{
				throw ex;
			}			
			return customClass;
		}

		/// <summary>
		/// We're only supporting three sections here at the moment.
		/// The default appSettings, plus our standard ApplicationConfiguration
		/// and CommonConfiguration section handlers. These handlers have extended support for
		/// the Description attribute in addition to the Key, Value pair attributes 
		/// in the Xml configuration file.
		/// </summary>
		public void SaveConfiguration(string configurationFile, CustomClass customClass)
		{
			try
			{
				//Reload the configuration file
				XmlDocument xmlDoc = new XmlDocument();
				xmlDoc.Load(configurationFile);
				//Save a backup version
				xmlDoc.Save(configurationFile + "_bak");
				//Populate our property collection. 
				PropertyDescriptorCollection props = customClass.GetProperties();
				//Repolulate the three supported sections
				RepopulateXmlSection("ApplicationConfiguration", xmlDoc, props);
				RepopulateXmlSection("CommonConfiguration", xmlDoc, props);
				RepopulateXmlSection("appSettings", xmlDoc, props);
				xmlDoc.Save(configurationFile);								
			}
			catch(Exception ex)
			{
				throw ex;				
			}
		}


		/// <summary>
		/// Repopulates the Xml section in the Xml Document by finding the matching key name
		/// values in the property collection and Xml node list.
		/// </summary>
		private void RepopulateXmlSection(string sectionName, XmlDocument xmlDoc, PropertyDescriptorCollection props)
		{
			XmlNodeList nodes = xmlDoc.SelectNodes("configuration/" + sectionName + "/add");
			for(int i = 0; i <  nodes.Count; i++)
			{
				//Find the property in the property collection with the same name as the current node in the Xml document
				CustomClass.DynamicProperty property = (CustomClass.DynamicProperty)props[nodes[i].Attributes["key"].Value];
				if (property != null)
				{
					//Set the node value to the property value (which will have been set in the Property grid.
					nodes[i].Attributes["value"].Value = property.GetValue(null).ToString();
					//Check to see if we have a value for our extended custom xml attribute - the description attribute.
					//The default description is the property name when no descripyion attribute is present.
					//If they're not the same - then a value was passed when the property was created.
					if (property.Description != property.Name)
					{
						//double check here that there is in fact a description attribute
						if (nodes[i].Attributes["description"] != null)
						{
							nodes[i].Attributes["description"].Value = property.Description;
						}
					}					
				}			
			}			
		}

		#endregion
		
		/// <summary>
		/// Clean up any resources being used.
		/// </summary>
		protected override void Dispose( bool disposing )
		{
			if( disposing )
			{
				if (components != null) 
				{
					components.Dispose();
				}
			}
			base.Dispose( disposing );
		}	
	}
}