CheckBoxListValidator.cs :  » Content-Management-Systems-CMS » mojoPortal » SurveyFeature » UI » C# / CSharp Open Source

using System.Web;
using System;
using System.ComponentModel;
using System.Collections.Generic;
using System.Text;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Xml;
using System.IO;
using System.Web.Configuration;
using System.Globalization;

//Taken from Scott Mitchell article http://scottonwriting.net/sowblog/posts/10039.aspx

namespace SurveyFeature.UI{
    public class CheckBoxListValidator : BaseValidator
    {
        [Description("The minimum number of CheckBoxes that must be checked to be considered valid.")]
        public int MinimumNumberOfSelectedCheckBoxes
        {
            get
            {
                object o = ViewState["MinimumNumberOfSelectedCheckBoxes"];
                if (o == null)
                    return 1;
                else
                    return (int)o;
            }
            set
            {
                ViewState["MinimumNumberOfSelectedCheckBoxes"] = value;
            }
        }

        private CheckBoxList _ctrlToValidate;

        protected CheckBoxList CheckBoxListToValidate
        {
            get
            {
                if (_ctrlToValidate == null)
                    _ctrlToValidate = FindControl(this.ControlToValidate) as CheckBoxList;

                return _ctrlToValidate;
            }
        }

        protected override bool ControlPropertiesValid()
        {
            // Make sure ControlToValidate is set
            if (this.ControlToValidate.Length == 0)
                throw new HttpException(string.Format(CultureInfo.CurrentCulture, "The ControlToValidate property of '{0}' cannot be blank.", this.ID));

            // Ensure that the control being validated is a CheckBoxList
            if (CheckBoxListToValidate == null)
                throw new HttpException(string.Format(CultureInfo.CurrentCulture, "The CheckBoxListValidator can only validate controls of type CheckBoxList."));

            // ... and that it has at least MinimumNumberOfSelectedCheckBoxes ListItems
            if (CheckBoxListToValidate.Items.Count < MinimumNumberOfSelectedCheckBoxes)
                throw new HttpException(string.Format(CultureInfo.CurrentCulture, "MinimumNumberOfSelectedCheckBoxes must be set to a value greater than or equal to the number of ListItems; MinimumNumberOfSelectedCheckBoxes is set to {0}, but there are only {1} ListItems in '{2}'", MinimumNumberOfSelectedCheckBoxes, CheckBoxListToValidate.Items.Count, CheckBoxListToValidate.ID));

            return true;    // if we reach here, everything checks out
        }

        protected override bool EvaluateIsValid()
        {
            // Make sure that the CheckBoxList has at least MinimumNumberOfSelectedCheckBoxes ListItems selected
            int selectedItemCount = 0;
            foreach (ListItem cb in CheckBoxListToValidate.Items)
                if (cb.Selected) selectedItemCount++;

            return selectedItemCount >= MinimumNumberOfSelectedCheckBoxes;
        }

        protected override void AddAttributesToRender(HtmlTextWriter writer)
        {
            base.AddAttributesToRender(writer);

            // Add the client-side code (if needed)
            if (this.RenderUplevel)
            {
                // Indicate the mustBeChecked value and the client-side function to used for evaluation
                // Use AddAttribute if Helpers.EnableLegacyRendering is true; otherwise, use expando attributes
                if (this.EnableLegacyRendering())
                {
                    writer.AddAttribute("evaluationfunction", "CheckBoxListValidatorEvaluateIsValid", false);
                    writer.AddAttribute("minimumNumberOfSelectedCheckBoxes", MinimumNumberOfSelectedCheckBoxes.ToString(CultureInfo.CurrentCulture), false);
                }
                else
                {
                    this.Page.ClientScript.RegisterExpandoAttribute(this.ClientID, "evaluationfunction", "CheckBoxListValidatorEvaluateIsValid", false);
                    this.Page.ClientScript.RegisterExpandoAttribute(this.ClientID, "minimumNumberOfSelectedCheckBoxes", MinimumNumberOfSelectedCheckBoxes.ToString(CultureInfo.CurrentCulture), false);
                }
            }
        }

        private bool EnableLegacyRendering()
        {
            return false;
           //bool result;

            //try
            //{
            //    string webConfigFile = Path.Combine(HttpContext.Current.Request.PhysicalApplicationPath, "web.config");
            //    XmlTextReader webConfigReader = new XmlTextReader(new StreamReader(webConfigFile));
            //    result = ((webConfigReader.ReadToFollowing("xhtmlConformance")) && (webConfigReader.GetAttribute("mode") == "Legacy"));
            //    webConfigReader.Close();
            //}
            //catch(ArgumentOutOfRangeException)
            //{
            //    result = false;
            //}
            //return result;
        }

        public void RegisterScripts()
        {
            string folderPath = WebConfigurationManager.AppSettings.Get("CSSFriendly-JavaScript-Path");
            if (String.IsNullOrEmpty(folderPath))
            {
                folderPath = "~/ClientScript";
            }
            string filePath = folderPath.EndsWith("/") ? folderPath + "skmValidators.js" : folderPath + "/skmValidators.js";
            this.Page.ClientScript.RegisterClientScriptInclude(GetType(), GetType().ToString(), this.Page.ResolveUrl(filePath));
        }

        protected override void OnPreRender(EventArgs e)
        {
            base.OnPreRender(e);
            RegisterScripts();

            // Register the client-side function using WebResource.axd (if needed)
            // see: http://aspnet.4guysfromrolla.com/articles/080906-1.aspx
            //if (this.RenderUplevel && this.Page != null && !this.Page.ClientScript.IsClientScriptIncludeRegistered(this.GetType(), "skmValidators"))
            //    this.Page.ClientScript.RegisterClientScriptInclude(this.GetType(), "skmValidators", this.Page.ClientScript.GetWebResourceUrl(this.GetType(), "skmValidators.skmValidators.js"));
        }

    }
}