private void ParseSegments(AstContext context)
{
var exprParser = new Parser(context.Language, _templateSettings.ExpressionRoot);
// As we go along the "value text" (that has all escapes done), we track the position in raw token text in the variable exprPosInTokenText.
// This position is position in original text in source code, including original escaping sequences and open/close quotes.
// It will be passed to segment constructor, and maybe used later to compute the exact position of runtime error when it occurs.
int currentPos = 0, exprPosInTokenText = 0;
while (true)
{
var startTagPos = _template.IndexOf(_templateSettings.StartTag, currentPos);
if (startTagPos < 0)
{
startTagPos = _template.Length;
}
var text = _template.Substring(currentPos, startTagPos - currentPos);
if (!string.IsNullOrEmpty(text))
{
_segments.Add(new TemplateSegment(text, null, 0)); //for text segments position is not used
}
if (startTagPos >= _template.Length)
{
break; //from while
}
//We have a real start tag, grab the expression
currentPos = startTagPos + _templateSettings.StartTag.Length;
var endTagPos = _template.IndexOf(_templateSettings.EndTag, currentPos);
if (endTagPos < 0)
{
//"No ending tag '{0}' found in embedded expression."
context.AddMessage(ErrorLevel.Error, this.Location, Resources.ErrNoEndTagInEmbExpr, _templateSettings.EndTag);
return;
}
var exprText = _template.Substring(currentPos, endTagPos - currentPos);
if (!string.IsNullOrEmpty(exprText))
{
//parse the expression
//_expressionParser.context.Reset();
var exprTree = exprParser.Parse(exprText);
if (exprTree.HasErrors())
{
//we use original search in token text instead of currentPos in template to avoid distortions caused by opening quote and escaped sequences
var baseLocation = this.Location + _tokenText.IndexOf(exprText);
CopyMessages(exprTree.ParserMessages, context.Messages, baseLocation, Resources.ErrInvalidEmbeddedPrefix);
return;
}
//add the expression segment
exprPosInTokenText = _tokenText.IndexOf(_templateSettings.StartTag, exprPosInTokenText) + _templateSettings.StartTag.Length;
var segmNode = exprTree.Root.AstNode as AstNode;
segmNode.Parent = this; //important to attach the segm node to current Module
_segments.Add(new TemplateSegment(null, segmNode, exprPosInTokenText));
//advance position beyond the expression
exprPosInTokenText += exprText.Length + _templateSettings.EndTag.Length;
} //if
currentPos = endTagPos + _templateSettings.EndTag.Length;
} //while
}
public override void Init(AstContext context, ParseTreeNode treeNode)
{
base.Init(context, treeNode);
if (!Exist1)
{
context.AddMessage(Irony.ErrorLevel.Error, Location, @"""Enter"" missing character list");
return;
}
}
