/// <summary>Attempts to parse key values from the specified text.</summary>
/// <param name='text'>Text to parse (not null).</param>
/// <param name="allowNamedValues">Set to true if the parser should accept named values
/// so syntax like Name='value'. If this is false, the parsing will fail on such constructs.</param>
/// <param name="allowNull">Set to true if the parser should accept null values.
/// If set to false, the parser will fail on null values.</param>
/// <param name='instance'>After invocation, the parsed key instance.</param>
/// <param name="enableUriTemplateParsing">Whether Uri template parsing is enabled.</param>
/// <returns>
/// true if the key instance was parsed; false if there was a
/// syntactic error.
/// </returns>
/// <remarks>
/// The returned instance contains only string values. To get typed values, a call to
/// TryConvertValues is necessary.
/// </remarks>
private static bool TryParseFromUri(string text, bool allowNamedValues, bool allowNull, out SegmentArgumentParser instance, bool enableUriTemplateParsing)
{
Debug.Assert(text != null, "text != null");
Dictionary <string, string> namedValues = null;
List <string> positionalValues = null;
// parse keys just like function parameters
ExpressionLexer lexer = new ExpressionLexer("(" + text + ")", true, false);
UriQueryExpressionParser exprParser = new UriQueryExpressionParser(ODataUriParserSettings.DefaultFilterLimit /* default limit for parsing key value */, lexer);
var tmp = (new FunctionCallParser(lexer, exprParser)).ParseArgumentListOrEntityKeyList();
if (lexer.CurrentToken.Kind != ExpressionTokenKind.End)
{
instance = null;
return(false);
}
if (tmp.Length == 0)
{
instance = Empty;
return(true);
}
string valueText = null;
foreach (FunctionParameterToken t in tmp)
{
valueText = null;
LiteralToken literalToken = t.ValueToken as LiteralToken;
if (literalToken != null)
{
valueText = literalToken.OriginalText;
// disallow "{...}" if enableUriTemplateParsing is false (which could have been seen as valid function parameter, e.g. array notation)
if (!enableUriTemplateParsing && UriTemplateParser.IsValidTemplateLiteral(valueText))
{
instance = null;
return(false);
}
}
else
{
DottedIdentifierToken dottedIdentifierToken = t.ValueToken as DottedIdentifierToken; // for enum
if (dottedIdentifierToken != null)
{
valueText = dottedIdentifierToken.Identifier;
}
}
if (valueText != null)
{
if (t.ParameterName == null)
{
if (namedValues != null)
{
instance = null; // We cannot mix named and non-named values.
return(false);
}
CreateIfNull(ref positionalValues);
positionalValues.Add(valueText);
}
else
{
if (positionalValues != null)
{
instance = null; // We cannot mix named and non-named values.
return(false);
}
CreateIfNull(ref namedValues);
namedValues.Add(t.ParameterName, valueText);
}
}
else
{
instance = null;
return(false);
}
}
instance = new SegmentArgumentParser(namedValues, positionalValues, false, enableUriTemplateParsing);
return(true);
}
/// <summary>
/// Whether given token is valid for keyPropertyValue, allow Uri template {key} if template parsing is enabled
/// </summary>
/// <param name="token">The literal token to be evaluated.</param>
/// <param name="enableUriTemplateParsing">Whether Uri template parsing is enabled.</param>
/// <returns>Whether token is valid for keyPropertyValue.</returns>
private static bool IsKeyValueToken(ExpressionToken token, bool enableUriTemplateParsing)
{
return(token.IsKeyValueToken || (enableUriTemplateParsing && UriTemplateParser.IsValidTemplateLiteral(token.Text)));
}