protected void ProcessForEach(Tag tag)
{
Expression expCollection = tag.AttributeValue("collection");
if (expCollection == null)
{
WriteError("Foreach is missing required attribute: collection", tag.Line, tag.Col);
return;
}
object collection = EvalExpression(expCollection);
if (!(collection is IEnumerable))
{
WriteError("Collection used in foreach has to be enumerable", tag.Line, tag.Col);
return;
}
Expression expVar = tag.AttributeValue("var");
if (expCollection == null)
{
WriteError("Foreach is missing required attribute: var", tag.Line, tag.Col);
return;
}
object varObject = EvalExpression(expVar);
if (varObject == null)
varObject = "foreach";
string varname = varObject.ToString();
Expression expIndex = tag.AttributeValue("index");
string indexname = null;
if (expIndex != null)
{
object obj = EvalExpression(expIndex);
if (obj != null)
indexname = obj.ToString();
}
IEnumerator ienum = ((IEnumerable)collection).GetEnumerator();
int index = 0;
while (ienum.MoveNext())
{
index++;
object value = ienum.Current;
variables[varname] = value;
if (indexname != null)
variables[indexname] = index;
ProcessElements(tag.InnerElements);
}
}
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);
}
protected void ProcessTag(Tag tag)
{
string name = tag.Name.ToLowerInvariant();
switch (name)
{
case "template":
// skip those, because those are processed first
break;
case "else":
ProcessElements(tag.InnerElements);
break;
case "apply":
object val = EvalExpression(tag.AttributeValue("template"));
ProcessTemplate(val.ToString(), tag);
break;
case "foreach":
ProcessForEach(tag);
break;
default:
ProcessTemplate(tag.Name, tag);
break;
}
}