private DbExpression RewriteCollection(DbExpression expression)
{
DbExpression dbExpression = expression;
DbProjectExpression projectExpression = (DbProjectExpression)null;
if (DbExpressionKind.Project == expression.ExpressionKind)
{
projectExpression = (DbProjectExpression)expression;
dbExpression = projectExpression.Input.Expression;
}
ObjectSpanRewriter.NavigationInfo navInfo = (ObjectSpanRewriter.NavigationInfo)null;
if (this.RelationshipSpan)
{
dbExpression = ObjectSpanRewriter.RelationshipNavigationVisitor.FindNavigationExpression(dbExpression, this._aliasGenerator, out navInfo);
}
if (navInfo != null)
{
this.EnterNavigationCollection(navInfo);
}
else
{
this.EnterCollection();
}
DbExpression body = expression;
if (projectExpression != null)
{
DbExpression projection = this.Rewrite(projectExpression.Projection);
if (!object.ReferenceEquals((object)projectExpression.Projection, (object)projection))
{
body = (DbExpression)dbExpression.BindAs(projectExpression.Input.VariableName).Project(projection);
}
}
else
{
DbExpressionBinding input = dbExpression.BindAs(this._aliasGenerator.Next());
DbExpression variable = (DbExpression)input.Variable;
DbExpression projection = this.Rewrite(variable);
if (!object.ReferenceEquals((object)variable, (object)projection))
{
body = (DbExpression)input.Project(projection);
}
}
this.ExitCollection();
if (navInfo != null && navInfo.InUse)
{
body = (DbExpression)DbExpressionBuilder.Lambda(body, (IEnumerable <DbVariableReferenceExpression>) new List <DbVariableReferenceExpression>(1)
{
navInfo.SourceVariable
}).Invoke((IEnumerable <DbExpression>) new List <DbExpression>(1)
{
navInfo.Source
});
}
return(body);
}
internal static DbExpression FindNavigationExpression(
DbExpression expression,
AliasGenerator aliasGenerator,
out ObjectSpanRewriter.NavigationInfo navInfo)
{
navInfo = (ObjectSpanRewriter.NavigationInfo)null;
TypeUsage typeUsage = ((CollectionType)expression.ResultType.EdmType).TypeUsage;
if (!TypeSemantics.IsEntityType(typeUsage) && !TypeSemantics.IsReferenceType(typeUsage))
{
return(expression);
}
ObjectSpanRewriter.RelationshipNavigationVisitor navigationVisitor = new ObjectSpanRewriter.RelationshipNavigationVisitor(aliasGenerator);
DbExpression dbExpression = navigationVisitor.Find(expression);
if (object.ReferenceEquals((object)expression, (object)dbExpression))
{
return(expression);
}
navInfo = new ObjectSpanRewriter.NavigationInfo(navigationVisitor._original, navigationVisitor._rewritten);
return(dbExpression);
}
private bool TryGetNavigationSource(
AssociationEndMember wasSourceNowTargetEnd,
out DbExpression source)
{
source = (DbExpression)null;
ObjectSpanRewriter.NavigationInfo navigationInfo = (ObjectSpanRewriter.NavigationInfo)null;
if (this._navSources.Count > 0)
{
navigationInfo = this._navSources.Peek();
if (navigationInfo != null && !object.ReferenceEquals((object)wasSourceNowTargetEnd, (object)navigationInfo.SourceEnd))
{
navigationInfo = (ObjectSpanRewriter.NavigationInfo)null;
}
}
if (navigationInfo == null)
{
return(false);
}
source = (DbExpression)navigationInfo.SourceVariable;
navigationInfo.InUse = true;
return(true);
}
private void EnterNavigationCollection(ObjectSpanRewriter.NavigationInfo info)
{
this._navSources.Push(info);
}
