/**
* Builds a certificate reference expression that is an {@link ExtensionField}.
* @param token The token used to build the field.
* @return An {@link ExtensionField} object that represents the token. Returns null if the token does not represent an {@link ExtensionField}.
* @throws PolicyParseException
*/
public IPolicyExpression BuildExtensionField(String token) //throws PolicyParseException
{
IPolicyExpression retVal = null;
ExtensionIdentifier fieldType = ExtensionIdentifier.FromToken(token);
bool required = token.EndsWith("+");
if (fieldType != null)
{
try
{
Type retType = fieldType.GetReferenceClass(token, required);
if (retType == null)
{
throw new PolicyParseException("ExtensionField with token name " + token + " has not been implemented yet.");
}
var ctor = retType.Ctor <bool, IPolicyExpression>();
retVal = ctor(required);
}
catch (PolicyParseException ex)
{
throw ex;
}
catch (Exception e)
{
throw new PolicyParseException("Error building ExtensionField", e);
}
}
return(retVal);
}
