DynamicControlParameter.cs source code in C# .NET

                        Code:
                         / 4.0 / 4.0 / untmp / DEVDIV_TFS / Dev10 / Releases / RTMRel / ndp / fx / src / xsp / System / DynamicData / DynamicData / DynamicControlParameter.cs / 1305376 / DynamicControlParameter.cs
                        
                        
                            using System.Collections.Generic; 
using System.Diagnostics;
using System.Globalization;
using System.Web.DynamicData.Util;
using System.Web.Resources; 
using System.Web.UI;
using System.Web.UI.WebControls; 
 
namespace System.Web.DynamicData {
 
    /// 
    /// DynamicControlParameter is similar to ControlParameter, but understainds higher level concepts.  e.g. in a
    /// master-details scenario using a GridView and DetailsView, you only need to point the DetailsView's datasource
    /// to the GridView (using a DynamicControlParameter), and it does the right thing.  This works even for 
    /// multi-part primary keys
    ///  
    public class DynamicControlParameter : Parameter, IWhereParametersProvider { 

        ///  
        /// 
        public DynamicControlParameter() { }

        ///  
        /// 
        public DynamicControlParameter(string controlId) { ControlId = controlId; } 
 
        /// 
        /// The ID of the control from which the parameter gets its data 
        /// 
        public string ControlId { get; set; }

        ///  
        /// See IWhereParametersProvider.GetWhereParameters
        ///  
        public virtual IEnumerable GetWhereParameters(IDynamicDataSource dataSource) { 
            Debug.Assert(dataSource != null);
 
            // Find the control that the ControlParameter uses
            Control control = Misc.FindControl((Control)dataSource, ControlId);

            if (control == null) { 
                throw new InvalidOperationException(String.Format(
                    CultureInfo.CurrentCulture, DynamicDataResources.DynamicControlParameter_DynamicDataSourceControlNotFound, ControlId)); 
            } 

            // If the control is itself a parameter provider, delegate to it 
            var whereParametersProvider = control as IWhereParametersProvider;
            if (whereParametersProvider != null) {
                return whereParametersProvider.GetWhereParameters(dataSource);
            } 

            IControlParameterTarget paramTarget = DynamicDataManager.GetControlParameterTarget(control); 
 
            if (paramTarget == null) {
                throw new InvalidOperationException(String.Format(CultureInfo.CurrentCulture, 
                    DynamicDataResources.DynamicControlParameter_DynamicDataSourceControlCannotBeUsedAsParent, ControlId));
            }

            string columnName = Name; 
            MetaColumn column = null;
            MetaTable table = MetaTableHelper.GetTableWithFullFallback(dataSource, HttpContext.Current.ToWrapper()); 
            if (!String.IsNullOrEmpty(columnName)) { 
                column = table.GetColumn(columnName);
            } 
            else {
                // There was no Name attribute telling us what field to filter, but maybe
                // the control given us data has that info
                column = paramTarget.FilteredColumn; 
            }
 
            if (column == null) { 
                // If there is no specific column, we're setting the primary key
 
                if (paramTarget.Table != table) {
                    throw new Exception(String.Format(CultureInfo.CurrentCulture,
                        DynamicDataResources.DynamicControlParameter_InvalidPK,
                        ControlId, paramTarget.Table, table.Name)); 
                }
 
                return GetPrimaryKeyControlWhereParameters(control, paramTarget); 
            }
            else if (column is MetaForeignKeyColumn) { 
                return GetForeignKeyControlWhereParameters(control, paramTarget, (MetaForeignKeyColumn)column);
            }
            return GetPropertyControlWhereParameters(control, paramTarget, column);
        } 

        private IEnumerable GetPropertyControlWhereParameters(Control control, 
            IControlParameterTarget paramTarget, MetaColumn column) { 
            ControlParameter controlParameter = new ControlParameter() {
                Name = column.Name, 
                ControlID = control.UniqueID,
                PropertyName = paramTarget.GetPropertyNameExpression(column.Name)
            };
 
            DataSourceUtil.SetParameterTypeCodeAndDbType(controlParameter, column);
 
            yield return controlParameter; 
        }
 
        private IEnumerable GetPrimaryKeyControlWhereParameters(Control control,
            IControlParameterTarget paramTarget) {

            MetaTable parentTable = paramTarget.Table; 
            if (parentTable != null) {
                // For each PK column in the table, we need to create a ControlParameter 
                foreach (var keyColumn in parentTable.PrimaryKeyColumns) { 
                    var controlParameter = new ControlParameter() {
                        Name = keyColumn.Name, 
                        ControlID = control.UniqueID,
                        PropertyName = paramTarget.GetPropertyNameExpression(keyColumn.Name)
                    };
 
                    DataSourceUtil.SetParameterTypeCodeAndDbType(controlParameter, keyColumn);
 
                    yield return controlParameter; 
                }
            } 
        }

        private IEnumerable GetForeignKeyControlWhereParameters(Control control,
            IControlParameterTarget paramTarget, MetaForeignKeyColumn column) { 

            MetaTable parentTable = paramTarget.Table; 
            if (parentTable != null) { 
                string namePrefix = String.Empty;
                // Make sure the data types match 
                if (column.ColumnType != parentTable.EntityType) {
                    throw new Exception(String.Format(CultureInfo.CurrentCulture,
                        DynamicDataResources.DynamicControlParameter_DynamicDataSourceColumnNotCompatibleWithTable,
                        column.DisplayName, parentTable.Name)); 
                }
 
                // For each underlying FK, we need to create a ControlParameter 
                Debug.Assert(column.ForeignKeyNames.Count == parentTable.PrimaryKeyColumns.Count);
                int index = 0; 
                foreach (var fkName in column.ForeignKeyNames) {
                    MetaColumn parentTablePKColumn = parentTable.PrimaryKeyColumns[index++];

                    var controlParameter = new ControlParameter() { 
                        Name = fkName,
                        ControlID = control.UniqueID, 
                        PropertyName = paramTarget.GetPropertyNameExpression(parentTablePKColumn.Name) 
                    };
 
                    DataSourceUtil.SetParameterTypeCodeAndDbType(controlParameter, parentTablePKColumn);

                    yield return controlParameter;
                } 
            }
        } 
 
        /// 
        /// same as base 
        /// 
        /// 
        /// 
        ///  
        protected override object Evaluate(HttpContext context, Control control) {
            // If this gets called, it means we never had a chance to expand the parameter. Give an error 
            // telling the user to use a DynamicDataManager 
            throw new InvalidOperationException(String.Format(
                CultureInfo.CurrentCulture, DynamicDataResources.DynamicParameter_NeedExpansion, typeof(DynamicControlParameter).Name)); 
        }
    }
}

// File provided for Reference Use Only by Microsoft Corporation (c) 2007.
// Copyright (c) Microsoft Corporation. All rights reserved.
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DynamicControlParameter.cs source code in C# .NET

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