private void ExecuteCustomTag(TagNode tag)
{
ITagHandler tagHandler = customTags[tag.TagName];
bool processInnerElements = tagHandler.TagEnter(this);
foreach (TagNodeAttribute attribute in tag.Attributes) {
if (!tagHandler.TagAttribute(attribute.Name, EvaluateExpression(attribute.Value)))
throw new TemplateException(String.Format("{0} missing required attribute: {1}", tag.TagName, attribute.Name), tag.Line, tag.Column);
}
if (processInnerElements) {
TextWriter saveWriter = writer;
writer = new StringWriter();
string innerContent ;
try {
ProcessNodes(tag.ChildNodes);
innerContent = writer.ToString();
} finally {
writer = saveWriter;
}
tagHandler.TagContent(innerContent);
}
tagHandler.TagExit(this);
}
private TagNode CollectForTag(TagNode tag, ref int index)
{
if (tag.Closed) // if self-closing tag, do not collect inner elements
return tag;
if (String.Compare(tag.TagName, "if", true) == 0) {
tag = new IfTag(tag.Line, tag.Column, tag.GetAttributeValue("test"));
}
TagNode collectTag = tag;
for (index++; index < nodes.Count; index++) {
Node node = nodes[index];
if (node is TextNode)
collectTag.ChildNodes.Add(node);
else if (node is Expression)
collectTag.ChildNodes.Add(node);
else if (node is TagNode) {
TagNode innerTag = (TagNode)node;
if (string.Compare(innerTag.TagName, "else", true) == 0) {
if (collectTag is IfTag) {
((IfTag)collectTag).FalseBranch = innerTag;
collectTag = innerTag;
} else
throw new ParseException("else tag has to be positioned inside of if or elseif tag", innerTag.Line, innerTag.Column);
} else if (string.Compare(innerTag.TagName, "elif", true) == 0) {
if (collectTag is IfTag) {
TagNode newTag = new IfTag(innerTag.Line, innerTag.Column, innerTag.GetAttributeValue("test"));
((IfTag)collectTag).FalseBranch = newTag;
collectTag = newTag;
} else
throw new ParseException("elseif tag is not positioned properly", innerTag.Line, innerTag.Column);
} else
collectTag.ChildNodes.Add(CollectForTag(innerTag, ref index));
} else if (node is TagEnd) {
TagEnd tagClose = (TagEnd)node;
if (string.Compare(tag.TagName, tagClose.TagName, true) == 0)
return tag;
throw new ParseException("Close tag for " + tagClose.TagName + " doesn't have matching start tag.", node.Line, node.Column);
} else
throw new ParseException("Invalid node: " + node.GetType(), node.Line, node.Column);
}
throw new ParseException("Start tag: " + tag.TagName + " does not have matching end tag.", tag.Line, tag.Column);
}
private TagNode ReadTag()
{
Consume(TokenKind.TagStart);
Token name = Consume(TokenKind.ID);
TagNode tag = new TagNode(name.Line, name.Column, name.Text);
while (true) {
if (Current.Kind == TokenKind.ID)
tag.Attributes.Add(ReadAttribute());
else if (Current.Kind == TokenKind.TagEnd) {
Consume();
break;
} else if (Current.Kind == TokenKind.TagEndClose) {
Consume();
tag.Closed = true;
break;
} else
throw new ParseException("Invalid token in tag: " + Current.Kind, Current.Line, Current.Column);
}
return tag;
}
private void ProcessTemplate(string name, TagNode tag)
{
if (customTags != null && customTags.ContainsKey(name)) {
ExecuteCustomTag(tag);
return;
}
Template useTemplate = currentTemplate.FindTemplate(name);
if (useTemplate == null)
throw new TemplateException(String.Format("Template '{0}' not found", name), tag.Line, tag.Column);
// process inner elements and save content
TextWriter saveWriter = writer;
writer = new StringWriter();
string content = String.Empty;
try {
ProcessNodes(tag.ChildNodes);
content = writer.ToString();
} finally {
writer = saveWriter;
}
Template saveTemplate = currentTemplate;
variableScope = new VariableScope(variableScope);
variableScope["innerText"] = content;
try {
foreach (TagNodeAttribute attrib in tag.Attributes) {
object val = EvaluateExpression(attrib.Value);
variableScope[attrib.Name] = val;
}
currentTemplate = useTemplate;
ProcessNodes(currentTemplate.Nodes);
} finally {
variableScope = variableScope.Parent;
currentTemplate = saveTemplate;
}
}
private void ProcessTagSet(TagNode tag)
{
Expression expName = tag.GetAttributeValue("name");
if (expName == null)
throw new TemplateException("Set is missing required attribute: name", tag.Line, tag.Column);
Expression expValue = tag.GetAttributeValue("value");
if (expValue == null)
throw new TemplateException("Set is missing required attribute: value", tag.Line, tag.Column);
string name = EvaluateExpression(expName).ToString();
if (!Util.IsValidVariableName(name))
throw new TemplateException("'" + name + "' is not valid variable name.", expName.Line, expName.Column);
object value = EvaluateExpression(expValue);
SetValue(name, value);
}
private void ProcessTag(TagNode tag)
{
string name = tag.TagName.ToLowerInvariant();
try {
switch (name) {
case "template":
// skip those, because those are processed first
break;
case "else":
ProcessNodes(tag.ChildNodes);
break;
case "apply":
object val = EvaluateExpression(tag.GetAttributeValue("template"));
ProcessTemplate(val.ToString(), tag);
break;
case "foreach":
ProcessForEach(tag);
break;
case "for":
ProcessFor(tag);
break;
case "set":
ProcessTagSet(tag);
break;
default:
ProcessTemplate(tag.TagName, tag);
break;
}
} catch (TemplateException ex) {
OnError(ex);
} catch (Exception ex) {
OnError("Error executing tag '" + name + "': " + ex.Message, tag.Line, tag.Column);
}
}
private void ProcessForEach(TagNode tag)
{
Expression expCollection = tag.GetAttributeValue("collection");
if (expCollection == null)
throw new TemplateException("Foreach is missing required attribute: collection", tag.Line, tag.Column);
object collection = EvaluateExpression(expCollection);
if (!(collection is IEnumerable))
throw new TemplateException("Collection used in foreach has to be enumerable", tag.Line, tag.Column);
Expression expVar = tag.GetAttributeValue("var");
if (expCollection == null)
throw new TemplateException("Foreach is missing required attribute: var", tag.Line, tag.Column);
object varObject = EvaluateExpression(expVar);
if (varObject == null)
varObject = "foreach";
string varname = varObject.ToString();
Expression expIndex = tag.GetAttributeValue("index");
string indexname = null;
if (expIndex != null) {
object obj = EvaluateExpression(expIndex);
if (obj != null)
indexname = obj.ToString();
}
IEnumerator ienum = ((IEnumerable)collection).GetEnumerator();
int index = 0;
while (ienum.MoveNext()) {
index++;
object value = ienum.Current;
variableScope.SetValue(varname, value);
if (indexname != null)
variableScope.SetValue(indexname, index);
ProcessNodes(tag.ChildNodes);
}
}
private void ProcessFor(TagNode tag)
{
Expression expFrom = tag.GetAttributeValue("from");
if (expFrom == null)
throw new TemplateException("For is missing required attribute: from", tag.Line, tag.Column);
Expression expTo = tag.GetAttributeValue("to");
if (expTo == null)
throw new TemplateException("For is missing required attribute: to", tag.Line, tag.Column);
Expression expIndex = tag.GetAttributeValue("index");
if (expIndex == null)
throw new TemplateException("For is missing required attribute: index", tag.Line, tag.Column);
object obj = EvaluateExpression(expIndex);
string indexName = obj.ToString();
int start = Convert.ToInt32(EvaluateExpression(expFrom));
int end = Convert.ToInt32(EvaluateExpression(expTo));
for (int index = start; index < end; index++) {
SetValue(indexName, index);
//variables[indexName] = index;
ProcessNodes(tag.ChildNodes);
}
}
