/// <summary>
/// Find items based on a template pattern
/// </summary>
/// <param name="query"></param>
/// <param name="stopAfterFirst"></param>
/// <returns>Returns matching items if found. Returns empty (non-null) array if none found.</returns>
public JToken FindItems(JObject query, bool stopAfterFirst = true)
{
var results = new JArray();
foreach (var source in this.Items)
{
if (source.Value == null)
{
continue;
}
foreach (var candidateItem in source.Value)
{
var joItem = (JObject)candidateItem.DeepClone();
var u = Unification.Unify(joItem, query);
if (u == null)
{
continue;
}
joItem.Add("#unification", u);
results.Add(joItem);
if (stopAfterFirst)
{
return(results[0]);
}
}
}
return(results);
}
public JToken Query(JToken query)
{
if (query.Type == JTokenType.Object)
{
var joQuery = (JObject)query;
var select = joQuery["#select"];
if (select == null)
{
return(query);
}
else
{
joQuery.Remove("#select");
}
var result = new JArray();
// {"#item": "?x", "select": "username"}
foreach (var querySource in this.Items)
{
if (querySource.Value.Type == JTokenType.Object)
{
var joQuerySource = (JObject)querySource.Value;
var items = joQuerySource["items"];
if (items == null)
{
continue;
}
var jaItems = (JArray)items;
foreach (var item in jaItems)
{
var joItem = (JObject)item.DeepClone();
var unification = Unification.Unify(joItem, joQuery);
if (unification == null)
{
continue;
}
if (select == null)
{
joItem.Add("#unification", unification);
result.Add(joItem);
}
else
{
var sSelect = select.ToString();
if (sSelect == "*")
{
result.Add(joItem);
}
else
{
var value = joItem[select.ToString()];
result.Add(value);
}
}
}
}
}
if (result.Count == 1)
{
return(result.First);
}
else
{
return(result);
}
}
else if (query.Type == JTokenType.Array)
{
return(query);
}
else if (query.Type == JTokenType.String)
{
return(query);
}
return(null);
}