protected void ProcessIf(TagIf tagIf)
{
bool condition = false;
try
{
object value = EvalExpression(tagIf.Test);
condition = Util.ToBool(value);
}
catch (Exception ex)
{
DisplayError("Error evaluating condition for if statement: " + ex.Message,
tagIf.Line, tagIf.Col);
return;
}
if (condition)
ProcessElements(tagIf.InnerElements);
else
ProcessElement(tagIf.FalseBranch);
}
private Tag CollectForTag(Tag tag, ref int index)
{
if (tag.IsClosed) // if self-closing tag, do not collect inner elements
{
return tag;
}
if (string.Compare(tag.Name, "if", true) == 0)
{
tag = new TagIf(tag.Line, tag.Col, tag.AttributeValue("test"));
}
Tag collectTag = tag;
for (index++; index < elements.Count; index++)
{
Element elem = elements[index];
if (elem is Text)
collectTag.InnerElements.Add(elem);
else if (elem is Expression)
collectTag.InnerElements.Add(elem);
else if (elem is Tag)
{
Tag innerTag = (Tag)elem;
if (string.Compare(innerTag.Name, "else", true) == 0)
{
if (collectTag is TagIf)
{
((TagIf)collectTag).FalseBranch = innerTag;
collectTag = innerTag;
}
else
throw new ParseException("else tag has to be positioned inside of if or elseif tag", innerTag.Line, innerTag.Col);
}
else if (string.Compare(innerTag.Name, "elseif", true) == 0)
{
if (collectTag is TagIf)
{
Tag newTag = new TagIf(innerTag.Line, innerTag.Col, innerTag.AttributeValue("test"));
((TagIf)collectTag).FalseBranch = newTag;
collectTag = newTag;
}
else
throw new ParseException("elseif tag is not positioned properly", innerTag.Line, innerTag.Col);
}
else
collectTag.InnerElements.Add(CollectForTag(innerTag, ref index));
}
else if (elem is TagClose)
{
TagClose tagClose = (TagClose)elem;
if (string.Compare(tag.Name, tagClose.Name, true) == 0)
return tag;
throw new ParseException("Close tag for " + tagClose.Name + " doesn't have matching start tag.", elem.Line, elem.Col);
}
else
throw new ParseException("Invalid element: " + elem.GetType().ToString(), elem.Line, elem.Col);
}
throw new ParseException("Start tag: " + tag.Name + " does not have matching end tag.", tag.Line, tag.Col);
}
