Relationship.cs source code in C# .NET

                        Code:
                         / 4.0 / 4.0 / untmp / DEVDIV_TFS / Dev10 / Releases / RTMRel / ndp / fx / src / DataEntity / System / Data / EntityModel / SchemaObjectModel / Relationship.cs / 1305376 / Relationship.cs
                        
                        
                            //---------------------------------------------------------------------- 
// 
//      Copyright (c) Microsoft Corporation.  All rights reserved.
// 
// 
// @owner       [....]
// @backupOwner [....] 
//--------------------------------------------------------------------- 

using System; 
using System.Data.Objects.DataClasses;
using System.Collections.Generic;
using System.Diagnostics;
using System.Xml; 
using System.Data;
using System.Data.Metadata.Edm; 
 

namespace System.Data.EntityModel.SchemaObjectModel 
{
    /// 
    /// Represents an Association element
    ///  
    internal sealed class Relationship : SchemaType, IRelationship
    { 
        private RelationshipKind _relationshipKind; 
        private RelationshipEndCollection _ends;
        private List _constraints; 
        private bool _isForeignKey;

        /// 
        /// Construct a Relationship object 
        /// 
        /// the parent 
        /// the kind of relationship 
        public Relationship(Schema parent, RelationshipKind kind)
        : base(parent) 
        {
            RelationshipKind = kind;

            if (Schema.DataModel == SchemaDataModelOption.EntityDataModel) 
            {
                _isForeignKey = false; 
                OtherContent.Add(Schema.SchemaSource); 
            }
            else if (Schema.DataModel == SchemaDataModelOption.ProviderDataModel) 
            {
                _isForeignKey = true;
            }
        } 

 
        ///  
        /// List of Ends defined for this Association
        ///  
        public IList Ends
        {
            get
            { 
                if ( _ends == null )
                    _ends = new RelationshipEndCollection(); 
                return _ends; 
            }
        } 

        /// 
        /// Returns the list of constraints on this relation
        ///  
        public IList Constraints
        { 
            get 
            {
                if (_constraints == null) 
                {
                    _constraints = new List();
                }
                return _constraints; 
            }
        } 
 
        public bool TryGetEnd( string roleName, out IRelationshipEnd end )
        { 
            return _ends.TryGetEnd( roleName, out end );
        }

 
        /// 
        /// Is this an Association 
        ///  
        public RelationshipKind RelationshipKind
        { 
            get
            {
                return _relationshipKind;
            } 
            private set
            { 
                _relationshipKind = value; 
            }
        } 

        /// 
        /// Is this a foreign key (aka foreign key) relationship?
        ///  
        public bool IsForeignKey
        { 
            get { return _isForeignKey; } 
        }
 
        /// 
        /// do whole element validation
        /// 
        ///  
        internal override void Validate()
        { 
            base.Validate(); 

            bool foundOperations = false; 
            foreach ( RelationshipEnd end in Ends )
            {
                end.Validate();
                if ( RelationshipKind == RelationshipKind.Association ) 
                {
                    if ( end.Operations.Count > 0 ) 
                    { 
                        if ( foundOperations )
                            end.AddError( ErrorCode.InvalidOperation, EdmSchemaErrorSeverity.Error, System.Data.Entity.Strings.InvalidOperationMultipleEndsInAssociation); 
                        foundOperations = true;
                    }
                }
            } 

            if (Constraints.Count == 0) 
            { 
                if (this.Schema.DataModel == SchemaDataModelOption.ProviderDataModel)
                { 
                    AddError(ErrorCode.MissingConstraintOnRelationshipType,
                             EdmSchemaErrorSeverity.Error,
                             System.Data.Entity.Strings.MissingConstraintOnRelationshipType(FQName));
                } 
            }
            else 
            { 
                foreach (ReferentialConstraint constraint in Constraints)
                { 
                    constraint.Validate();
                }
            }
        } 

        ///  
        /// do whole element resolution 
        /// 
        internal override void ResolveTopLevelNames() 
        {
            base.ResolveTopLevelNames();

            foreach ( RelationshipEnd end in Ends ) 
                end.ResolveTopLevelNames();
 
            foreach (ReferentialConstraint referentialConstraint in Constraints) 
            {
                referentialConstraint.ResolveTopLevelNames(); 
            }
        }

        protected override bool HandleElement(XmlReader reader) 
        {
            if (base.HandleElement(reader)) 
            { 
                return true;
            } 
            else if (CanHandleElement(reader, XmlConstants.End))
            {
                HandleEndElement(reader);
                return true; 
            }
            else if (CanHandleElement(reader, XmlConstants.ReferentialConstraint)) 
            { 
                HandleConstraintElement(reader);
                return true; 
            }
            return false;
        }
 
        /// 
        /// handle the End child element 
        ///  
        /// XmlReader positioned at the end element
        private void HandleEndElement(XmlReader reader) 
        {
            Debug.Assert(reader != null);
            RelationshipEnd end = new RelationshipEnd(this);
            end.Parse(reader); 

            if (Ends.Count == 2) 
            { 
                AddError( ErrorCode.InvalidAssociation, EdmSchemaErrorSeverity.Error, System.Data.Entity.Strings.TooManyAssociationEnds(FQName ) );
                return; 
            }

            Ends.Add(end);
        } 

        ///  
        /// handle the constraint element 
        /// 
        /// XmlReader positioned at the constraint element 
        private void HandleConstraintElement(XmlReader reader)
        {
            Debug.Assert(reader != null);
 
            ReferentialConstraint constraint = new ReferentialConstraint(this);
            constraint.Parse(reader); 
            this.Constraints.Add(constraint); 

            if (this.Schema.DataModel == SchemaDataModelOption.EntityDataModel && this.Schema.SchemaVersion >= XmlConstants.EdmVersionForV2) 
            {
                // in V2, referential constraint implies foreign key
                _isForeignKey = true;
            } 
        }
 
    } 
}

// File provided for Reference Use Only by Microsoft Corporation (c) 2007.
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Relationship.cs source code in C# .NET

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