AssociationProvider.cs source code in C# .NET

Source code for the .NET framework in C#

                        
Code:

                         / 4.0 / 4.0 / untmp / DEVDIV_TFS / Dev10 / Releases / RTMRel / ndp / fx / src / xsp / System / DynamicData / DynamicData / ModelProviders / AssociationProvider.cs / 1305376 / AssociationProvider.cs
                        

                        
                            using System.Collections.ObjectModel; 
using System.Globalization;
using System.Web.Resources;

namespace System.Web.DynamicData.ModelProviders { 
    /// 
    /// Specifies the association cardinality 
    ///  
    public enum AssociationDirection {
        ///  
        /// 1-1
        /// 
        OneToOne,
        ///  
        /// one to many
        ///  
        OneToMany, 
        /// 
        /// many to one 
        /// 
        ManyToOne,
        /// 
        /// many to many 
        /// 
        ManyToMany 
    } 

    ///  
    /// Base provider class for associations between columns
    /// Each provider type (e.g. Linq To Sql, Entity Framework, 3rd party) extends this class.
    /// 
    public abstract class AssociationProvider { 
        private TableProvider _toTable;
 
        ///  
        /// The type of association
        ///  
        public virtual AssociationDirection Direction { get; protected set; }

        /// 
        /// The source column of the association 
        /// 
        public virtual ColumnProvider FromColumn { get; protected set; } 
 
        /// 
        /// The destination table of the association 
        /// 
        public virtual TableProvider ToTable {
            get {
                if (_toTable != null) { 
                    return _toTable;
                } 
 
                if (ToColumn != null) {
                    return ToColumn.Table; 
                }

                return null;
            } 
            protected set {
                _toTable = value; 
            } 
        }
 
        /// 
        /// The destination column of the association
        /// 
        public virtual ColumnProvider ToColumn { get; protected set; } 

        ///  
        /// Returns true if the From Column part of the primary key of its table 
        /// e.g. Order and Product are PKs in the Order_Details table
        ///  
        public virtual bool IsPrimaryKeyInThisTable { get; protected set; }

        /// 
        /// The names of the underlying foreign keys that make up this association 
        /// 
        [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", "CA2227:CollectionPropertiesShouldBeReadOnly", Justification="It's a readonly collection, so the warning is incorrect")] 
        public virtual ReadOnlyCollection ForeignKeyNames { get; protected set; } 

        ///  
        /// Returns a string representing the sort expression that would be used for
        /// sorting the column represented by this association. The parameter is the
        /// property of the strongly typed entity used as the sort key for that entity.
        /// For example, assume that this association represents the Category column 
        /// in the Products table. The sortColumn paramater is "CategoryName",
        /// meaning that this method is being asked to return the sort expression for 
        /// sorting the Category column by the CategoryName property of the Category entity. 
        /// The result sort expression would be "Category.CategoryName".
        /// The result of this method should be affected by whether the underlying data 
        /// model is capable of sorting the entity by the given sort column (see
        /// ColumnProvider.IsSortable). The method can return a null value to indicate
        /// that sorting is not supported.
        ///  
        /// the column to sort the entity by
        /// the sort expression string, or null if sort is not supported for the 
        /// given sort column 
        public virtual string GetSortExpression(ColumnProvider sortColumn) {
            return null; 
        }

        internal string GetSortExpression(ColumnProvider sortColumn, string format) {
            if (Direction == AssociationDirection.OneToMany || Direction == AssociationDirection.ManyToMany) { 
                throw new InvalidOperationException(String.Format(CultureInfo.CurrentCulture,
                    DynamicDataResources.AssociationProvider_DirectionDoesNotSupportSorting, 
                    Direction)); 
            }
 
            if (sortColumn == null) {
                throw new ArgumentNullException("sortColumn");
            }
 
            if (!ToTable.Columns.Contains(sortColumn)) {
                throw new ArgumentException(DynamicDataResources.AssociationProvider_SortColumnDoesNotBelongToEndTable, "sortColumn"); 
            } 

            if (sortColumn.IsSortable) { 
                return String.Format(CultureInfo.InvariantCulture, format, FromColumn.Name, sortColumn.Name);
            } else {
                return null;
            } 
        }
    } 
} 

// File provided for Reference Use Only by Microsoft Corporation (c) 2007.
// Copyright (c) Microsoft Corporation. All rights reserved.

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