SharePoint CAML Query Builder Dialog for your Web Parts

using System;
using System.Collections;
using System.Configuration;
using System.Data;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.HtmlControls;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using Microsoft.SharePoint.WebControls;
using Microsoft.SharePoint.Utilities;
using Microsoft.SharePoint;
using System.Text;
using System.Collections.Generic;
using System.Xml;
using System.Reflection;
using Mullivan.SharePoint.Pages.WebControls;
using Mullivan.SharePoint.WebControls;

namespace Mullivan.SharePoint.Pages
{
    public partial class _FieldValueDialog : System.Web.UI.Page
    {
        private ClientScriptManager _csm = null;
        private Type _type = null;
        private SPList _list = null;
        private SPField _spField = null;
        private SPFieldRenderer _control = null;

        public string ListUrl
        {
            get
            {
                if (this.ViewState["ListUrl"] != null)
                    return (string)this.ViewState["ListUrl"];
                else
                    return string.Empty;
            }
            set
            {
                this.ViewState["ListUrl"] = value;
            }
        }

        public string EditField
        {
            get
            {
                if (this.ViewState["EditField"] != null)
                    return (string)this.ViewState["EditField"];
                else
                    return string.Empty;
            }
            set
            {
                this.ViewState["EditField"] = value;
            }
        }

        public string InitialValue
        {
            get
            {
                if (this.ViewState["InitialValue"] != null)
                    return (string)this.ViewState["InitialValue"];
                else
                    return string.Empty;
            }
            set
            {
                this.ViewState["InitialValue"] = value;
            }
        }

        public _FieldValueDialog()
        {
            _csm = Page.ClientScript;
            _type = typeof(_FieldValueDialog);
        }

        protected override void OnInit(EventArgs e)
        {
            base.OnInit(e);

            queryBuilderIcon.ImageUrl = ResolveUrl(_csm.GetWebResourceUrl(_type, "Mullivan.SharePoint.Pages.Images.edit32.png"));
            dialogDescription.Text = "Use this page to edit a value for a List Field.";
            dialogTitle.Text = "Field Editor - {0}";
        }

        protected override void OnLoad(EventArgs e)
        {
            base.OnLoad(e);

            ((DialogMaster)base.Master).OkButton.Click += new EventHandler(OkButton_Click);
            if (base.IsPostBack)
            {
                if (!SPUtility.ValidateFormDigest())
                {
                    throw new SPException("Security Validation Failed");
                }

                _list = GetList(this.ListUrl);

                if (_list == null)
                    throw new SPException("List not found.");
            }
            else
            {

                this.ProcessQueryString();

                _list = GetList(this.ListUrl);

                if (_list == null)
                    throw new SPException("List not found.");
            }
            _spField = _list.Fields.GetFieldByInternalName(this.EditField);

            if (_spField != null)
            {
                lblColumnName.Text = _spField.Title;
                lblColumnType.Text = _spField.TypeDisplayName;
                dialogTitle.Text = string.Format(dialogTitle.Text, _spField.Title);

                _control = new SPFieldRenderer();
                _control.Field = _spField;
                _control.List = _list;

                pnlEditContainer.Controls.Add(_control);

                if(!Page.IsPostBack)
                    _control.Value = this.InitialValue;

            }
            else
                throw new Exception(string.Format("Field {0} could not be found.", this.EditField));
        }

        private void ProcessQueryString()
        {
            string strListUrl = string.Empty;
            string strField = string.Empty;
            string strInitialValue = string.Empty;

            if (string.IsNullOrEmpty(strListUrl = Request.QueryString["list"]))
                throw new SPException("List not found.");
            if (string.IsNullOrEmpty(strField = Request.QueryString["field"]))
                strField = string.Empty;
            if (string.IsNullOrEmpty(strInitialValue = Request.QueryString["value"]))
                strInitialValue = string.Empty;

            this.InitialValue = strInitialValue;
            this.ListUrl = strListUrl;
            this.EditField = strField;
        }

        private SPList GetList(string listUrl)
        {
            
            SPSite site = SPControl.GetContextSite(this.Context);

            using (SPWeb web = site.OpenWeb(GetWebUrl(listUrl)))
            {
                string listName = GetListName(listUrl);
                return web.Lists[listName];
            }
        }

        private string GetWebUrl(string listUrl)
        {
            string webUrl = string.Empty;
            listUrl = listUrl.TrimEnd('/');
            int lastIndex = listUrl.LastIndexOf("/");
            if (lastIndex > -1)
                webUrl = listUrl.Substring(0, lastIndex);

            return webUrl.TrimEnd('/');
        }

        private string GetListName(string listUrl)
        {
            string listName = string.Empty;
            listUrl = listUrl.Trim('/');
            int lastIndex = listUrl.LastIndexOf("/");
            if (lastIndex > -1)
                listName = listUrl.Substring(lastIndex + 1, listUrl.Length - lastIndex - 1);

            return listName;
        }

        private void OkButton_Click(object sender, EventArgs e)
        {
            _control.Validate();
            if (!_control.IsValid)
                return;

            string val = _control.Value;
            if (!string.IsNullOrEmpty(val))
                val = val.Replace("'", "\\'");
            else
                val = string.Empty;

            StringBuilder sb = new StringBuilder();
            sb.AppendLine("<script type=\"text/javascript\" Language=\"javascript\">");
            sb.AppendLine(string.Format("HandleOkClicked('{0}');", val));
            sb.AppendLine("</script>");

            _csm.RegisterStartupScript(_type, "FieldEditSetOk", sb.ToString());

        }

    }
}