/// <summary>
/// This is used to apply the context rules successively to the code string that needs colorizing.
/// </summary>
/// <param name="languageNode">The language node.</param>
/// <param name="contextNode">The context node.</param>
/// <param name="code">The code block to parse and convert.</param>
/// <param name="parsedCodeNode">Parent node that will contain the parsed code.</param>
/// <remarks>This method uses the pre-computed regular expressions of the context rules, rule matching,
/// etc. The results are added to the XML document in the parsedcodeNode.</remarks>
/// <exception cref="InvalidOperationException">This is thrown if a rule match cannot be found or if a
/// matching context node cannot be found.</exception>
private void ApplyRules(XmlNode languageNode, XmlNode contextNode, string code, XmlNode parsedCodeNode)
{
XmlNode attributeNode;
Regex regExp;
Match m;
// Get the regular expression for the default context
regExp = rxDic.GetKey(languageNode, contextNode);
while(code.Length > 0)
{
// Apply
m = regExp.Match(code);
if(!m.Success)
{
parsedCodeNode.XmlAddChildCDATAElem(contextNode.Attributes["attribute"].Value, code);
// Finished parsing
break;
}
// Add the skipped text if not empty
if(m.Index != 0)
{
attributeNode = contextNode.Attributes["attribute"];
if(attributeNode != null && attributeNode.Value != "hidden")
parsedCodeNode.XmlAddChildCDATAElem(attributeNode.Value, code.Substring(0, m.Index));
}
// Find the rule that caused the match
XmlNode ruleNode = this.FindRule(languageNode, contextNode, m.Value);
if(ruleNode == null)
throw new InvalidOperationException("Didn't find matching rule, regular expression false? " +
"(context: " + contextNode.Attributes["id"].Value + ")");
// Check to see if the match needs to be added to the result
attributeNode = ruleNode.Attributes["attribute"];
if(attributeNode != null && attributeNode.Value != "hidden")
parsedCodeNode.XmlAddChildCDATAElem(attributeNode.Value, m.Value);
// Update the context if necessary
if(contextNode.Attributes["id"].Value != ruleNode.Attributes["context"].Value)
{
// Get the new context
contextNode = languageNode.SelectSingleNode("contexts/context[@id=\"" + ruleNode.Attributes[
"context"].Value + "\"]");
if(contextNode == null)
throw new InvalidOperationException("Didn't find matching context, error in XML " +
"specification?");
// Get the new regular expression
regExp = rxDic.GetKey(languageNode, contextNode);
}
// Removed the parsed code and carry on
code = code.Substring(m.Index + m.Length);
}
}
