public virtual SequenceNode ParseSyntaxTree(string bbCode)
{
if (bbCode == null)
{
throw new ArgumentNullException("bbCode");
}
Stack <SyntaxTreeNode> stack = new Stack <SyntaxTreeNode>();
var rootNode = new SequenceNode();
stack.Push(rootNode);
int end = 0;
while (end < bbCode.Length)
{
if (MatchTagEnd(bbCode, ref end, stack))
{
continue;
}
if (MatchStartTag(bbCode, ref end, stack))
{
continue;
}
if (MatchTextNode(bbCode, ref end, stack))
{
continue;
}
if (ErrorMode != ErrorMode.ErrorFree)
{
throw new BBCodeParsingException(""); //there is no possible match at the current position
}
AppendText(bbCode[end].ToString(), stack); //if the error free mode is enabled force interpretation as text if no other match could be made
end++;
}
Debug.Assert(end == bbCode.Length); //assert bbCode was matched entirely
while (stack.Count > 1) //close all tags that are still open and can be closed implicitly
{
var node = (TagNode)stack.Pop();
if (node.Tag.RequiresClosingTag && ErrorMode == ErrorMode.Strict)
{
throw new BBCodeParsingException(MessagesHelper.GetString("TagNotClosed", node.Tag.Name));
}
}
if (stack.Count != 1)
{
Debug.Assert(ErrorMode != ErrorMode.ErrorFree);
throw new BBCodeParsingException(""); //only the root node may be left
}
return(rootNode);
}
bool ErrorOrReturn(string msgKey, params string[] parameters)
{
if (ErrorMode == ErrorMode.ErrorFree)
{
return(true);
}
else
{
throw new BBCodeParsingException(string.IsNullOrEmpty(msgKey) ? "" : MessagesHelper.GetString(msgKey, parameters));
}
}
string ParseText(string input, ref int pos)
{
int end = pos;
bool escapeFound = false;
bool anyEscapeFound = false;
while (end < input.Length)
{
if (input[end] == '[' && !escapeFound)
{
break;
}
if (input[end] == ']' && !escapeFound)
{
if (ErrorMode == ErrorMode.Strict)
{
throw new BBCodeParsingException(MessagesHelper.GetString("NonescapedChar"));
}
}
if (input[end] == '\\' && !escapeFound)
{
escapeFound = true;
anyEscapeFound = true;
}
else if (escapeFound)
{
if (!(input[end] == '[' || input[end] == ']' || input[end] == '\\'))
{
if (ErrorMode == ErrorMode.Strict)
{
throw new BBCodeParsingException(MessagesHelper.GetString("EscapeChar"));
}
}
escapeFound = false;
}
end++;
}
if (escapeFound)
{
if (ErrorMode == ErrorMode.Strict)
{
throw new BBCodeParsingException("");
}
}
var result = input.Substring(pos, end - pos);
if (anyEscapeFound)
{
var result2 = new char[result.Length];
int writePos = 0;
bool lastWasEscapeChar = false;
for (int i = 0; i < result.Length; i++)
{
if (!lastWasEscapeChar && result[i] == '\\')
{
if (i < result.Length - 1)
{
if (!(result[i + 1] == '[' || result[i + 1] == ']' || result[i + 1] == '\\'))
{
result2[writePos++] = result[i]; //the next char was not escapable. write the slash into the output array
}
else
{
lastWasEscapeChar = true; //the next char is meant to be escaped so the backslash is skipped
}
}
else
{
result2[writePos++] = '\\'; //the backslash was the last char in the string. just write it into the output array
}
}
else
{
result2[writePos++] = result[i];
lastWasEscapeChar = false;
}
}
result = new string(result2, 0, writePos);
}
pos = end;
return(result == "" ? null : result);
}
