public Func <TwitterStatus, bool> GetEvaluator()
{
var sourcesEvals = Sources.Select(s => s.GetEvaluator());
var predEvals = PredicateTreeRoot != null
? PredicateTreeRoot.GetEvaluator()
: FilterExpressionBase.Contradiction;
return(_ => sourcesEvals.Any(f => f(_)) && predEvals(_));
}
public void Deactivate()
{
Sources?.ForEach(s =>
{
s.InvalidateRequired -= RaiseInvalidateRequired;
s.Deactivate();
});
if (PredicateTreeRoot != null)
{
PredicateTreeRoot.InvalidateRequested -= RaiseInvalidateRequired;
PredicateTreeRoot.EndLifecycle();
}
}
public void Activate()
{
Sources?.ForEach(s =>
{
s.Activate();
s.InvalidateRequired += RaiseInvalidateRequired;
});
if (PredicateTreeRoot != null)
{
PredicateTreeRoot.BeginLifecycle();
PredicateTreeRoot.InvalidateRequested += RaiseInvalidateRequired;
}
}
public string ToQuery()
{
return("from " + Sources.GroupBy(s => s.FilterKey)
.Select(g => g.Distinct(_ => _.FilterValue).ToArray()) // remove duplicated query
.Select(fs =>
{
if (fs.Length == 1 && String.IsNullOrEmpty(fs[0].FilterValue))
{
// if filter value is not specified, return filter key only.
return fs[0].FilterKey;
}
return fs[0].FilterKey + ": " +
fs.Select(f => f.FilterValue.EscapeForQuery().Quote())
.JoinString(", ");
})
.JoinString(", ") +
" where " + PredicateTreeRoot.ToQuery());
}
public string GetSqlQuery()
{
var source =
Sources.Guard()
.Select(s => s.GetSqlQuery())
.JoinString(" or ");
var predicate = PredicateTreeRoot != null
? PredicateTreeRoot.GetSqlQuery()
: String.Empty;
if (!String.IsNullOrEmpty(source))
{
if (!String.IsNullOrEmpty(predicate))
{
return("(" + source + ") and (" + predicate + ")");
}
return(source);
}
return(!String.IsNullOrEmpty(predicate)
? predicate
: FilterExpressionBase.ContradictionSql);
}
