/// <summary>
/// Sanitizes the stream of nodes into exclusively valid AOML.
/// This process involves changing and removing nodes.
/// </summary>
public void Sanitize(NodeCollection nodes)
{
if (nodes == null)
{
throw new ArgumentNullException();
}
// Loop through all nodes
nodes.Reset();
Node node = null;
while ((node = nodes.Next()) != null)
{
// Skip content nodes
if (node.Type == NodeType.Content)
{
continue;
}
// Gather info
OpenNode openNode = null;
CloseNode closeNode = null;
string name = null;
if (node.Type == NodeType.Open)
{
openNode = (OpenNode)node;
name = openNode.Name;
// Check attributes
for (int i = 0; i < openNode.Count; i++)
{
string attr = openNode.GetAttributeName(i);
if (!validAttributes.Contains(attr))
{
openNode.RemoveAttribute(attr);
i--;
}
}
}
else if (node.Type == NodeType.Close)
{
closeNode = (CloseNode)node;
name = closeNode.Name;
}
// Singular elements
if (singularElements.Contains(name))
{
// Singular elements don't have closing nodes
if (closeNode != null)
{
nodes.Remove(closeNode);
}
// Singular elements are always self-closing
if (openNode != null)
{
openNode.Closed = true;
}
continue;
}
else if (inlineElements.Contains(name) || blockElements.Contains(name))
{
if (openNode == null)
{
continue;
}
// Let's not use self-closing elements here
if (openNode.Closed)
{
openNode.Closed = false;
nodes.InsertAfter(openNode, new CloseNode(name, ""));
}
continue;
}
// Replace node as content node
if (this.InvalidElementsToContent)
{
// Replace node as content
this.ReplaceContent(nodes, node, node.Raw, node.Raw);
}
else
{
// Remove node
this.ReplaceContent(nodes, node, "", "");
}
}
// And we're done!
nodes.Reset();
}
/// <summary>
/// Balances out the stream of nodes to form a valid tree.
/// This process will always try to resolve conflicts by introducing extra inline elements over block elements.
/// </summary>
public void Balance(NodeCollection nodes)
{
if (nodes == null)
{
throw new ArgumentNullException();
}
// Fill in missing elements
List <string> nameStack = new List <string>();
nodes.Reset();
Node node = null;
while ((node = nodes.Next()) != null)
{
switch (node.Type)
{
case NodeType.Open:
OpenNode openNode = (OpenNode)node;
if (openNode.Closed)
{
continue;
}
nameStack.Insert(0, openNode.Name);
break;
case NodeType.Close:
CloseNode closeNode = (CloseNode)node;
if (!nameStack.Contains(closeNode.Name))
{
// Found CloseNode without OpenNode
// Fix by insert an OpenNode before it
nodes.InsertBefore(
closeNode,
new OpenNode(closeNode.Name, "", false));
}
nameStack.Remove(closeNode.Name);
break;
}
}
while (nameStack.Count > 0)
{
// Found OpenNode without CloseNode
// Fix by adding a CloseNode at the end of the stream
string name = nameStack[0];
nameStack.RemoveAt(0);
nodes.Add(new CloseNode(name, ""));
}
// Resolve tree structure
List <OpenNode> nodeStack = new List <OpenNode>();
nodes.Reset();
while ((node = nodes.Next()) != null)
{
switch (node.Type)
{
case NodeType.Open:
OpenNode on = (OpenNode)node;
if (on.Closed)
{
continue;
}
nodeStack.Insert(0, on);
break;
case NodeType.Close:
// A bit of setup
CloseNode closeNode = (CloseNode)node;
bool block = blockElements.Contains(closeNode.Name);
// Find matching OpenNode
OpenNode openNode = null;
foreach (OpenNode o in nodeStack)
{
if (o.Name == closeNode.Name)
{
openNode = o;
break;
}
}
if (openNode == null)
{
throw new InvalidOperationException("Unable to find matching OpenNode to CloseNode");
}
// Handle incorrect balance
int offset = 0;
while (nodeStack[offset].Name != closeNode.Name)
{
OpenNode n = nodeStack[offset];
if (block)
{
nodes.InsertBefore(node, new CloseNode(n.Name, ""));
nodes.InsertAfter(node, n.Clone());
nodeStack.RemoveAt(offset);
offset--;
}
else
{
nodes.InsertBefore(n, closeNode.Clone());
nodes.InsertAfter(n, openNode.Clone());
}
offset++;
}
// All fixed
nodeStack.RemoveAt(offset);
break;
}
}
// And we're done!
nodes.Reset();
}
public Element Parse(string aoml)
{
ContainerElement container = new ContainerElement();
// Parse AOML
NodeCollection nodes = this.Parser.Parse(aoml);
this.Parser.Sanitize(nodes);
this.Parser.Balance(nodes);
// Transform AOML into a DOM tree
Stack <Element> elements = new Stack <Element>();
elements.Push(container);
foreach (Node node in nodes)
{
Element element = null;
switch (node.Type)
{
case NodeType.Content:
// Content doesn't introduce a new level
// We'll simply add it as child at the current depth
ContentNode content = (ContentNode)node;
element = new TextElement(Web.UnescapeHtml(content.Value));
elements.Peek().Children.Add(element);
break;
case NodeType.Open:
OpenNode open = (OpenNode)node;
switch (open.Name)
{
case "br":
// Singular linebreak element
element = new BreakElement();
elements.Peek().Children.Add(element);
break;
case "img":
// Singular image element
element = this.CreateImageElement(open);
if (element != null)
{
elements.Peek().Children.Add(element);
}
break;
case "font":
element = this.CreateFontElement(open);
elements.Peek().Children.Add(element);
if (!open.Closed)
{
elements.Push(element);
}
break;
case "a":
element = this.CreateLinkElement(open);
elements.Peek().Children.Add(element);
if (!open.Closed)
{
elements.Push(element);
}
break;
case "u":
element = new UnderlineElement();
elements.Peek().Children.Add(element);
if (!open.Closed)
{
elements.Push(element);
}
break;
case "i":
element = new ItalicElement();
elements.Peek().Children.Add(element);
if (!open.Closed)
{
elements.Push(element);
}
break;
case "center":
case "left":
case "right":
case "div":
Alignment alignment = Alignment.Inherit;
if (open.Name == "center" || open.GetAttribute("align") == "center")
{
alignment = Alignment.Center;
}
else if (open.Name == "left" || open.GetAttribute("align") == "left")
{
alignment = Alignment.Left;
}
else if (open.Name == "right" || open.GetAttribute("align") == "right")
{
alignment = Alignment.Right;
}
element = new AlignElement(alignment);
elements.Peek().Children.Add(element);
if (!open.Closed)
{
elements.Push(element);
}
break;
default:
throw new ArgumentException("Unexpected tag: " + open.Name);
}
break;
case NodeType.Close:
// Closing a node means consuming an element from the stack
// But first check whether the node matches the element on the stack
CloseNode close = (CloseNode)node;
switch (close.Name)
{
case "br":
throw new ArgumentException("Unexpected 'br' closing tag");
case "img":
throw new ArgumentException("Unexpected 'img' closing tag");
case "font":
if (elements.Peek().Type == ElementType.Color)
{
break;
}
if (elements.Peek().Type == ElementType.Container)
{
break;
}
throw new ArgumentException("Unexpected 'font' closing tag");
case "a":
if (elements.Peek().Type == ElementType.Link)
{
break;
}
if (elements.Peek().Type == ElementType.Container)
{
break;
}
throw new ArgumentException("Unexpected 'a' closing tag");
case "u":
if (elements.Peek().Type == ElementType.Underline)
{
break;
}
throw new ArgumentException("Unexpected 'u' closing tag");
case "i":
if (elements.Peek().Type == ElementType.Italic)
{
break;
}
throw new ArgumentException("Unexpected 'i' closing tag");
case "div":
case "center":
case "left":
case "right":
if (elements.Peek().Type == ElementType.Align)
{
break;
}
throw new ArgumentException("Unexpected '" + close.Name + "' closing tag");
default:
throw new ArgumentException("Unexpected tag: " + close.Name);
}
if (elements.Count <= 1)
{
throw new ArgumentException("Unexpected closing tag");
}
// Go 1 step back down in the tree
elements.Pop();
break;
default:
throw new InvalidOperationException("Unexpected node type");
}
}
// Let's report our progress
if (container.Children.Count == 0)
{
return(null);
}
if (container.Children.Count == 1)
{
return(container.Children.ToArray()[0]);
}
return(container);
}