/// <summary>
/// Generates assocation keys in metadata.
/// </summary>
/// <param name="association">Association model.</param>
/// <param name="backReference">Association side.</param>
private void BuildAssociationMetadataKey(AssociationModel association, bool backReference)
{
// metadata model to update with keys
var metadata = backReference ? association.TargetMetadata : association.SourceMetadata;
// if metadata keys already specified in model, skip generation
// (we don't generate them before this stage, so it means user generated them manually)
if (metadata.ExpressionPredicate != null ||
metadata.QueryExpressionMethod != null ||
metadata.ThisKey != null ||
metadata.ThisKeyExpression != null ||
metadata.OtherKey != null ||
metadata.OtherKeyExpression != null)
{
return;
}
if (association.FromColumns == null ||
association.ToColumns == null ||
association.FromColumns.Length != association.ToColumns.Length ||
association.FromColumns.Length == 0)
{
throw new InvalidOperationException($"Invalid association configuration: association columns missing or mismatch on both sides of assocation.");
}
var thisColumns = backReference ? association.ToColumns : association.FromColumns;
var otherColumns = !backReference ? association.ToColumns : association.FromColumns;
var thisBuilder = !backReference ? _entityBuilders[association.Source] : _entityBuilders[association.Target];
var otherBuilder = backReference ? _entityBuilders[association.Source] : _entityBuilders[association.Target];
// we generate keys using nameof operator to get property name to have refactoring-friendly mappings
// (T4 always used strings here)
var separator = association.FromColumns.Length > 1 ? AST.Constant(",", true) : null;
for (var i = 0; i < association.FromColumns.Length; i++)
{
if (i > 0)
{
// add comma separator
metadata.ThisKeyExpression = AST.Add(metadata.ThisKeyExpression !, separator !);
metadata.OtherKeyExpression = AST.Add(metadata.OtherKeyExpression !, separator !);
}
// generate nameof() expressions for current key column
var thisKey = AST.NameOf(AST.Member(thisBuilder.Type.Type, _columnProperties[thisColumns [0]].Reference));
var otherKey = AST.NameOf(AST.Member(otherBuilder.Type.Type, _columnProperties[otherColumns[0]].Reference));
// append column name to key
metadata.ThisKeyExpression = metadata.ThisKeyExpression == null ? thisKey : AST.Add(metadata.ThisKeyExpression, thisKey);
metadata.OtherKeyExpression = metadata.OtherKeyExpression == null ? otherKey : AST.Add(metadata.OtherKeyExpression, thisKey);
}
}
