DLinqColumnProvider.cs source code in C# .NET

                        Code:
                         / 4.0 / 4.0 / untmp / DEVDIV_TFS / Dev10 / Releases / RTMRel / ndp / fx / src / xsp / System / DynamicData / DynamicData / ModelProviders / DLinqColumnProvider.cs / 1305376 / DLinqColumnProvider.cs
                        
                        
                            using System.Collections.Generic; 
using System.ComponentModel;
using System.ComponentModel.DataAnnotations;
using System.Data.Linq;
using System.Data.Linq.Mapping; 
using System.Globalization;
using System.Reflection; 
using System.Text.RegularExpressions; 
using System.Xml.Linq;
 
namespace System.Web.DynamicData.ModelProviders {
    internal sealed class DLinqColumnProvider : ColumnProvider {
        private static Regex s_varCharRegEx = new Regex(@"N?(?:Var)?Char\(([0-9]+)\)", RegexOptions.IgnoreCase); // accepts char, nchar, varchar, and nvarchar
 
        private AttributeCollection _attributes;
        private AssociationProvider _association; 
        private bool _isAssociation; 

        public DLinqColumnProvider(DLinqTableProvider table, MetaDataMember member) 
            : base(table) {
            Member = member;
            Name = member.Name;
            ColumnType = GetMemberType(member); 
            IsPrimaryKey = member.IsPrimaryKey;
            IsGenerated = member.IsDbGenerated; 
            _isAssociation = member.IsAssociation; 
            IsCustomProperty = !member.IsAssociation && Member.DbType == null;
            Nullable = Member.IsAssociation ? Member.Association.IsNullable : Member.CanBeNull; 
            MaxLength = ProcessMaxLength(ColumnType, Member.DbType);
            IsSortable = ProcessIsSortable(ColumnType, Member.DbType);
        }
 
        public override AttributeCollection Attributes {
            get { 
                if (!Member.IsDiscriminator) 
                    return base.Attributes;
 
                if (_attributes == null) {
                    List newAttributes = new List();
                    bool foundScaffoldAttribute = false;
 
                    foreach (Attribute attr in base.Attributes) {
                        if (attr is ScaffoldColumnAttribute) { 
                            foundScaffoldAttribute = true; 
                            break;
                        } 
                        newAttributes.Add(attr);
                    }

                    if (foundScaffoldAttribute) 
                        _attributes = base.Attributes;
                    else { 
                        newAttributes.Add(new ScaffoldColumnAttribute(false)); 
                        _attributes = new AttributeCollection(newAttributes.ToArray());
                    } 
                }

                return _attributes;
            } 
        }
 
        // internal to facilitate unit testing 
        internal static int ProcessMaxLength(Type memberType, String dbType) {
            // Only strings and chars that come in from a database have max lengths 
            if (dbType == null || (memberType != typeof(string) && Misc.RemoveNullableFromType(memberType) != typeof(char)))
                return 0;

            if (dbType.StartsWith("NText", StringComparison.OrdinalIgnoreCase)) { 
                return Int32.MaxValue >> 1; // see sql server 2005 spec for ntext
            } 
 
            if (dbType.StartsWith("Text", StringComparison.OrdinalIgnoreCase)) {
                return Int32.MaxValue; // see sql server 2005 spec for text 
            }

            if (dbType.StartsWith("NVarChar(MAX)", StringComparison.OrdinalIgnoreCase)) {
                return (Int32.MaxValue >> 1) - 2; // see sql server 2005 spec for nvarchar 
            }
 
            if (dbType.StartsWith("VarChar(MAX)", StringComparison.OrdinalIgnoreCase)) { 
                return Int32.MaxValue - 2; // see sql server 2005 spec for varchar
            } 

            Match m = s_varCharRegEx.Match(dbType);
            if (m.Success) {
                return Int32.Parse(m.Groups[1].Value, CultureInfo.InvariantCulture); 
            }
 
            return 0; 
        }
 
        internal static bool ProcessIsSortable(Type memberType, String dbType) {
            if (dbType == null)
                return false;
 
            if (memberType == typeof(string) &&
                (dbType.StartsWith("Text", StringComparison.OrdinalIgnoreCase) 
                  || dbType.StartsWith("NText", StringComparison.OrdinalIgnoreCase))) { 
                return false;
            } 

            if (memberType == typeof(Binary) && dbType.StartsWith("Image", StringComparison.OrdinalIgnoreCase)) {
                return false;
            } 

            if (memberType == typeof(XElement)) { 
                return false; 
            }
 
            return true;
        }

        internal MetaDataMember Member { 
            get;
            private set; 
        } 

        internal void Initialize() { 
            if (_isAssociation && _association == null) {
                _association = new DLinqAssociationProvider(this);
            }
        } 

        internal bool ShouldRemove { get; set; } 
 
        private static Type GetMemberType(MetaDataMember member) {
            Type type = member.Type; 
            if (type.IsGenericType && type.GetGenericTypeDefinition() == typeof(EntitySet<>)) {
                return type.GetGenericArguments()[0];
            }
            else { 
                return type;
            } 
        } 

        #region IEntityMember Members 

        public override PropertyInfo EntityTypeProperty {
            get { return (PropertyInfo)Member.Member; }
        } 

        public override AssociationProvider Association { 
            get { 
                Initialize();
 
                return _association;
            }
        }
 
        internal new bool IsForeignKeyComponent {
            set { 
                base.IsForeignKeyComponent = value; 
            }
        } 

        #endregion
    }
} 

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

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