/// <summary>
/// Returns true if there is a metadata expression (outside of a transform) in the expression.
/// </summary>
internal static bool ContainsMetadataExpressionOutsideTransform(string expression)
{
ItemsAndMetadataPair pair = new ItemsAndMetadataPair(null, null);
GetReferencedItemNamesAndMetadata(expression, 0, expression.Length, ref pair, ShredderOptions.MetadataOutsideTransforms);
bool result = (pair.Metadata != null && pair.Metadata.Count > 0);
return result;
}
/// <summary>
/// Given a subexpression, finds referenced item names and inserts them into the table
/// as K=Name, V=String.Empty.
/// </summary>
/// <remarks>
/// We can ignore any semicolons in the expression, since we're not itemizing it.
/// </remarks>
private static void GetReferencedItemNamesAndMetadata(string expression, int start, int end, ref ItemsAndMetadataPair pair, ShredderOptions whatToShredFor)
{
for (int i = start; i < end; i++)
{
int restartPoint;
if (Sink(expression, ref i, end, '@', '('))
{
// Start of a possible item list expression
// Store the index to backtrack to if this doesn't turn out to be a well
// formed metadata expression. (Subtract one for the increment when we loop around.)
restartPoint = i - 1;
SinkWhitespace(expression, ref i);
int startOfName = i;
if (!SinkValidName(expression, ref i, end))
{
i = restartPoint;
continue;
}
// '-' is a legitimate char in an item name, but we should match '->' as an arrow
// in '@(foo->'x')' rather than as the last char of the item name.
// The old regex accomplished this by being "greedy"
if (end > i && expression[i - 1] == '-' && expression[i] == '>')
{
i--;
}
// Grab the name, but continue to verify it's a well-formed expression
// before we store it.
string name = expression.Substring(startOfName, i - startOfName);
SinkWhitespace(expression, ref i);
// If there's an '->' eat it and the subsequent quoted expression
if (Sink(expression, ref i, end, '-', '>'))
{
SinkWhitespace(expression, ref i);
if (!SinkSingleQuotedExpression(expression, ref i, end))
{
i = restartPoint;
continue;
}
}
SinkWhitespace(expression, ref i);
// If there's a ',', eat it and the subsequent quoted expression
if (Sink(expression, ref i, ','))
{
SinkWhitespace(expression, ref i);
if (!Sink(expression, ref i, '\''))
{
i = restartPoint;
continue;
}
int closingQuote = expression.IndexOf('\'', i);
if (closingQuote == -1)
{
i = restartPoint;
continue;
}
// Look for metadata in the separator expression
// e.g., @(foo, '%(bar)') contains batchable metadata 'bar'
GetReferencedItemNamesAndMetadata(expression, i, closingQuote, ref pair, ShredderOptions.MetadataOutsideTransforms);
i = closingQuote + 1;
}
SinkWhitespace(expression, ref i);
if (!Sink(expression, ref i, ')'))
{
i = restartPoint;
continue;
}
// If we've got this far, we know the item expression was
// well formed, so make sure the name's in the table
if ((whatToShredFor & ShredderOptions.ItemTypes) != 0)
{
pair.Items = Utilities.CreateTableIfNecessary(pair.Items);
pair.Items[name] = String.Empty;
}
i--;
continue;
}
if (Sink(expression, ref i, end, '%', '('))
{
// Start of a possible metadata expression
// Store the index to backtrack to if this doesn't turn out to be a well
// formed metadata expression. (Subtract one for the increment when we loop around.)
restartPoint = i - 1;
SinkWhitespace(expression, ref i);
int startOfText = i;
if (!SinkValidName(expression, ref i, end))
{
i = restartPoint;
continue;
}
// Grab this, but we don't know if it's an item or metadata name yet
string firstPart = expression.Substring(startOfText, i - startOfText);
string itemName = null;
string metadataName;
string qualifiedMetadataName;
SinkWhitespace(expression, ref i);
bool qualified = Sink(expression, ref i, '.');
if (qualified)
{
SinkWhitespace(expression, ref i);
startOfText = i;
if (!SinkValidName(expression, ref i, end))
{
i = restartPoint;
continue;
}
itemName = firstPart;
metadataName = expression.Substring(startOfText, i - startOfText);
qualifiedMetadataName = itemName + "." + metadataName;
}
else
{
metadataName = firstPart;
qualifiedMetadataName = metadataName;
}
SinkWhitespace(expression, ref i);
if (!Sink(expression, ref i, ')'))
{
i = restartPoint;
continue;
}
if ((whatToShredFor & ShredderOptions.MetadataOutsideTransforms) != 0)
{
pair.Metadata = Utilities.CreateTableIfNecessary(pair.Metadata);
pair.Metadata[qualifiedMetadataName] = new MetadataReference(itemName, metadataName);
}
i--;
}
}
}
/// <summary>
/// Given a list of expressions that may contain item list expressions,
/// returns a pair of tables of all item names found, as K=Name, V=String.Empty;
/// and all metadata not in transforms, as K=Metadata key, V=MetadataReference,
/// where metadata key is like "itemname.metadataname" or "metadataname".
/// PERF: Tables are null if there are no entries, because this is quite a common case.
/// </summary>
internal static ItemsAndMetadataPair GetReferencedItemNamesAndMetadata(List<string> expressions)
{
ItemsAndMetadataPair pair = new ItemsAndMetadataPair(null, null);
foreach (string expression in expressions)
{
GetReferencedItemNamesAndMetadata(expression, 0, expression.Length, ref pair, ShredderOptions.All);
}
return pair;
}
