private MarkdownNode Parse(string rawMarkdown)
{
MarkdownNode root = new MarkdownNode()
{
Type = MarkdownType.Root
};
_current = root;
string[] lines = rawMarkdown.Split(new[] { "\r\n", "\r", "\n" },
StringSplitOptions.None);
foreach (var line in lines)
{
foreach (var handler in _handlers)
{
if (handler.HandleLine(_current, line))
{
break;
}
}
}
return(root);
}
public bool HandleLine(MarkdownNode context, string line)
{
line = line.Trim();
bool isBullet;
int skip;
if (line.StartsWith("-"))
{
isBullet = true;
skip = 1;
}
else if (line.StartsWith("#."))
{
isBullet = false;
skip = 2;
}
else
{
return(false);
}
var bulletNode = new MarkdownNode()
{
Type = isBullet ? MarkdownType.Bulleted : MarkdownType.Numbered,
};
context.AddChild(bulletNode);
AppendParsedTextTo(bulletNode, line.Substring(skip).Trim());
return(true);
}
public bool HandleLine(MarkdownNode context, string line)
{
line = line.Trim();
var headingTag = GetHeadingTag(line);
if (headingTag == null)
{
return(false);
}
MarkdownType type;
switch (headingTag)
{
case "#": type = MarkdownType.Heading1; break;
case "##": type = MarkdownType.Heading2; break;
case "###": type = MarkdownType.Heading3; break;
default: return(false);
}
string headingText = line.Substring(headingTag.Length).Trim();
var node = new MarkdownNode()
{
Type = type,
Text = headingText
};
context.AddChild(node);
return(true);
}
private bool nextSatisfies(int i, MarkdownNode parent, Func <MarkdownNode, bool> predicate)
{
i += 1;
if (i < 0 || i >= parent.Children.Count)
{
return(false);
}
var node = parent.Children[i];
return(predicate(node));
}
public void RemoveChild(MarkdownNode child)
{
if (child.Parent == this)
{
_children.Remove(child);
child.Parent = null;
if (_children.Count == 0)
{
_children = null;
}
}
}
public void AddChild(MarkdownNode child)
{
if (child.Parent != null)
{
child.Parent.RemoveChild(child);
}
child.Parent = this;
if (_children == null)
{
_children = new List <MarkdownNode>();
}
_children.Add(child);
}
public bool HandleLine(MarkdownNode context, string line)
{
line = line.Trim();
var para = new MarkdownNode()
{
Type = MarkdownType.Paragraph
};
context.AddChild(para);
AppendParsedTextTo(para, line);
return(true);
}
protected void AppendParsedTextTo(MarkdownNode parent, string line)
{
var ranges = Parse(line);
Stack <MarkdownNode> stack = new Stack <MarkdownNode>();
foreach (var range in ranges)
{
if (range.IsEmpty)
{
throw new Exception("Unexpected empty markdown paragraph range.");
}
stack.Clear();
stack.Push(new MarkdownNode()
{
Type = MarkdownType.Text, Text = range.ExtractText(line)
});
if (range.Underline)
{
stack.Push(new MarkdownNode()
{
Type = MarkdownType.Underline
});
}
if (range.Italic)
{
stack.Push(new MarkdownNode()
{
Type = MarkdownType.Italic
});
}
if (range.Bold)
{
stack.Push(new MarkdownNode()
{
Type = MarkdownType.Bold
});
}
var node = parent;
while (stack.Count > 0)
{
var child = stack.Pop();
node.AddChild(child);
node = child;
}
}
}
private void RenderNode(MarkdownNode node, StringBuilder builder)
{
string openTag = null;
string closeTag = null;
switch (node.Type)
{
case MarkdownType.Heading1: openTag = "<span style=\"font-size: 140%; font-weight: bold\">"; closeTag = "</span>"; break;
case MarkdownType.Heading2: openTag = "<span style=\"font-size: 120%; font-weight: bold; font-style=italic;\">"; closeTag = "</span>"; break;
case MarkdownType.Heading3: openTag = "<span style=\"font-size: 105%; font-weight: bold\">"; closeTag = "</span>"; break;
// case MarkdownType.Bulleted: openTag = "<ul>"; closeTag = "</ul>"; break;
// case MarkdownType.Numbered: openTag = "<ol>"; closeTag = "</ol>"; break;
case MarkdownType.Bold: openTag = "<b>"; closeTag = "</b>"; break;
case MarkdownType.Italic: openTag = "<i>"; closeTag = "</i>"; break;
case MarkdownType.Underline: openTag = "<u>"; closeTag = "</u>"; break;
//case MarkdownType.BlankLine: openTag = null; closeTag = "<br>"; break;
default: break;
}
if (openTag != null)
{
builder.Append(openTag);
}
if (node.Text != null)
{
builder.Append(WebUtility.HtmlEncode(node.Text));
}
for (int i = 0; i < node.Children.Count; ++i)
{
var child = node.Children[i];
if (child.Type == MarkdownType.Bulleted)
{
if (!previousSatisfies(i, node, n => n.Type == MarkdownType.Bulleted))
{
builder.AppendLine();
builder.AppendLine("<ul>");
}
builder.Append("<li>");
RenderNode(child, builder);
builder.AppendLine("</li>");
if (!nextSatisfies(i, node, n => n.Type == MarkdownType.Bulleted))
{
builder.AppendLine();
builder.AppendLine("</ul>");
}
}
else if (child.Type == MarkdownType.Numbered)
{
if (!previousSatisfies(i, node, n => n.Type == MarkdownType.Numbered))
{
builder.AppendLine();
builder.AppendLine("<ol>");
}
builder.Append("<li>");
RenderNode(child, builder);
builder.AppendLine("</li>");
if (!nextSatisfies(i, node, n => n.Type == MarkdownType.Numbered))
{
builder.AppendLine();
builder.AppendLine("</ol>");
}
}
else if (child.Type == MarkdownType.Paragraph)
{
if (!previousSatisfies(i, node, n => n.Type == MarkdownType.Paragraph))
{
builder.AppendLine();
builder.AppendLine("<p>");
}
else
{
builder.AppendLine("<br>");
}
RenderNode(child, builder);
if (!nextSatisfies(i, node, n => n.Type == MarkdownType.Paragraph))
{
builder.AppendLine();
builder.AppendLine("</p>");
}
}
else
{
RenderNode(child, builder);
}
}
if (closeTag != null)
{
if (node.IsInlineModifier)
{
builder.Append(closeTag);
}
else
{
builder.AppendLine(closeTag);
}
}
}
public Markdown(string rawMarkdown)
{
_root = Parse(rawMarkdown);
}