private void ExpandItem()
{
if (_parser.CurrentTokenKind == QueryExpressionTokenKind.Identifier)
{
var member = _parser.BindMember((string)_parser.TokenData);
if (!(member is PropertyInfo property) ||
!IsNavigationProperty(property, out var itemType, out var isCollection))
{
_parser.ReportError($"Property '{_parser.TokenData}' is no navigation property");
return;
}
if (_clauses.ContainsKey(property))
{
_parser.ReportError($"Property '{_parser.TokenData}' is already expanded.");
return;
}
var clause = new ExpandClause(itemType, property, isCollection);
_clauses[property] = clause;
_parser.NextToken();
if (_parser.CurrentTokenKind == QueryExpressionTokenKind.OpenParenthesis)
{
_parser.NextToken();
ExpandItemOptions(clause);
}
}
}
private void SelectItem(SelectClause currentClause)
{
switch (_parser.CurrentTokenKind)
{
case QueryExpressionTokenKind.Star:
_parser.NextToken();
currentClause.IsStarSelect = true;
break;
case QueryExpressionTokenKind.Identifier:
{
var member = _parser.BindMember((string)_parser.TokenData) as PropertyInfo;
if (member == null)
{
_parser.ReportError($"'{_parser.TokenData}' is not a valid property for selection");
return;
}
_parser.NextToken();
// not yet selected -> create subclause
if (!currentClause.SelectClauses.TryGetValue(member, out var subClause))
{
subClause = new SelectClause();
subClause.SelectedMember = member;
currentClause.SelectClauses[member] = subClause;
}
// nested expression
if (_parser.CurrentTokenKind == QueryExpressionTokenKind.Slash)
{
_parser.NextToken();
// activate sub clauses
subClause.SelectClauses = new Dictionary <PropertyInfo, SelectClause>();
// parse next segment into this subclause
if (IsNavigationProperty(member, out var expressionType, out _))
{
_parser.PushThis(Expression.Parameter(expressionType));
SelectItem(subClause);
_parser.PopThis();
}
else if (member.DeclaringType != null)
{
_parser.ReportError($"'{member.DeclaringType.FullName}.{member.Name}' is no navigation property, cannot expand with slash");
}
else
{
_parser.ReportError($"'{member.Name}' is no navigation property, cannot expand with slash");
}
}
else
{
// $select=complexProperty/subproperty is equal to $select=complexProperty/subproperty/*
subClause.IsStarSelect = true;
}
break;
}