public static RuleExpressionInfo Validate(RuleValidation validation, CodeExpression expression, bool isWritten)
{
if (validation == null)
{
throw new ArgumentNullException("validation");
}
// See if we've visited this node before.
// Always check if written = true
RuleExpressionInfo resultExprInfo = null;
if (!isWritten)
{
resultExprInfo = validation.ExpressionInfo(expression);
}
if (resultExprInfo == null)
{
// First time we've seen this node.
RuleExpressionInternal ruleExpr = GetExpression(expression);
if (ruleExpr == null)
{
string message = string.Format(CultureInfo.CurrentCulture, Messages.CodeExpressionNotHandled, expression.GetType().FullName);
ValidationError error = new ValidationError(message, ErrorNumbers.Error_CodeExpressionNotHandled);
error.UserData[RuleUserDataKeys.ErrorObject] = expression;
if (validation.Errors == null)
{
string typeName = string.Empty;
if ((validation.ThisType != null) && (validation.ThisType.Name != null))
{
typeName = validation.ThisType.Name;
}
string exceptionMessage = string.Format(
CultureInfo.CurrentCulture, Messages.ErrorsCollectionMissing, typeName);
throw new InvalidOperationException(exceptionMessage);
}
else
{
validation.Errors.Add(error);
}
return(null);
}
resultExprInfo = validation.ValidateSubexpression(expression, ruleExpr, isWritten);
}
return(resultExprInfo);
}
internal override bool Validate(RuleValidation validation)
{
bool success = false;
string message;
RuleExpressionInfo lhsExprInfo = null;
if (assignStatement.Left == null)
{
ValidationError error = new ValidationError(Messages.NullAssignLeft, ErrorNumbers.Error_LeftOperandMissing);
error.UserData[RuleUserDataKeys.ErrorObject] = assignStatement;
validation.Errors.Add(error);
}
else
{
lhsExprInfo = validation.ExpressionInfo(assignStatement.Left);
if (lhsExprInfo == null)
{
lhsExprInfo = RuleExpressionWalker.Validate(validation, assignStatement.Left, true);
}
}
RuleExpressionInfo rhsExprInfo = null;
if (assignStatement.Right == null)
{
ValidationError error = new ValidationError(Messages.NullAssignRight, ErrorNumbers.Error_RightOperandMissing);
error.UserData[RuleUserDataKeys.ErrorObject] = assignStatement;
validation.Errors.Add(error);
}
else
{
rhsExprInfo = RuleExpressionWalker.Validate(validation, assignStatement.Right, false);
}
if (lhsExprInfo != null && rhsExprInfo != null)
{
Type expressionType = rhsExprInfo.ExpressionType;
Type assignmentType = lhsExprInfo.ExpressionType;
if (assignmentType == typeof(NullLiteral))
{
// Can't assign to a null literal.
ValidationError error = new ValidationError(Messages.NullAssignLeft, ErrorNumbers.Error_LeftOperandInvalidType);
error.UserData[RuleUserDataKeys.ErrorObject] = assignStatement;
validation.Errors.Add(error);
success = false;
}
else if (assignmentType == expressionType)
{
// Easy case, they're both the same type.
success = true;
}
else
{
// The types aren't the same, but it still might be a legal assignment.
if (!RuleValidation.TypesAreAssignable(expressionType, assignmentType, assignStatement.Right, out ValidationError error))
{
if (error == null)
{
message = string.Format(CultureInfo.CurrentCulture, Messages.AssignNotAllowed, RuleDecompiler.DecompileType(expressionType), RuleDecompiler.DecompileType(assignmentType));
error = new ValidationError(message, ErrorNumbers.Error_OperandTypesIncompatible);
}
error.UserData[RuleUserDataKeys.ErrorObject] = assignStatement;
validation.Errors.Add(error);
}
else
{
success = true;
}
}
}
return(success);
}