public PropertyGraphModel Transform(PropertyGraphModel graph)
{
var result = graph;
if (WhereClause != null)
{
result = WhereClause.Transform(result);
}
if (CalculateClause != null)
{
result = CalculateClause.Transform(result);
}
if (SelectPropsClause != null)
{
result = SelectPropsClause.Transform(result);
}
if (GroupByClause != null)
{
result = GroupByClause.Transform(result);
}
if (LayoutClause != null)
{
result = LayoutClause.Transform(result);
}
result.ClearIfEmpty();
return(result);
}
private SelectPropsClause ParseSelectPropsClause(ParseTreeNode node)
{
var result = new SelectPropsClause();
foreach (var prop in node.ChildNodes)
{
string alias = null;
if (prop.ChildNodes[1].ChildNodes.Count > 0)
{
alias = prop.ChildNodes[1].ChildNodes[1].ChildNodes[0].Token.ValueString;
}
if (string.Equals(prop.ChildNodes[0]?.Term?.Name,
"wildcardIdentifier", StringComparison.InvariantCultureIgnoreCase))
{
if (prop.ChildNodes[0].ChildNodes.Count == 1)
{
result.AddProp(
ParseWildcardIdentifier(prop.ChildNodes[0], alias)
);
}
else
{
ParseEdgeIdentifier(prop.ChildNodes[0], alias, result);
}
}
else
{
result.AddProp(
ParseSelectExpression(prop.ChildNodes[0], alias)
);
}
}
return(result);
}
private void ParseEdgeIdentifier(ParseTreeNode id, string alias, SelectPropsClause result)
{
//edge prop
string firstToken = id.ChildNodes[0].Token.ValueString.ToLower();
if (firstToken == "edge" || firstToken == "edges")
{
if (id.ChildNodes.Count == 2)
{
result.AddEdgeFilter(WildcardOrName(id.ChildNodes[1]), alias);
return;
}
if (id.ChildNodes.Count == 3)
{
result.AddEdgePropFilter(WildcardOrName(id.ChildNodes[1]),
WildcardOrName(id.ChildNodes[2]), alias);
return;
}
}
throw new GraphQuerySyntaxError("unknown property identifier");
}
