//common part
public static void Process(StringBuilder builder, ref ToPlainTextState state, params char[] chars)
{
foreach (var ch in chars)
{
if (char.IsWhiteSpace(ch))
{
if (IsHardSpace(ch))
{
if (state == ToPlainTextState.WhiteSpace)
{
builder.Append(' ');
}
builder.Append(' ');
state = ToPlainTextState.NotWhiteSpace;
}
else
{
if (state == ToPlainTextState.NotWhiteSpace)
{
state = ToPlainTextState.WhiteSpace;
}
}
}
else
{
if (state == ToPlainTextState.WhiteSpace)
{
builder.Append(' ');
}
builder.Append(ch);
state = ToPlainTextState.NotWhiteSpace;
}
}
}
public static string HtmlToPlainText(string htmlDoc)
{
HtmlDocument doc = new HtmlDocument();
doc.LoadHtml(htmlDoc);
StringBuilder builder = new StringBuilder();
ToPlainTextState state = ToPlainTextState.StartLine;
Plain(builder, ref state, new[] { doc.DocumentNode });
return(builder.ToString());
}
private static void Plain(StringBuilder builder, ref ToPlainTextState state, IEnumerable <XNode> nodes)
{
foreach (var node in nodes)
{
if (node is XElement)
{
var element = (XElement)node;
var tag = element.Name.LocalName.ToLower();
if (tag == "br")
{
builder.AppendLine();
state = ToPlainTextState.StartLine;
}
else if (NonVisibleTags.Contains(tag))
{
}
else if (InlineTags.Contains(tag))
{
Plain(builder, ref state, element.Nodes());
}
else
{
if (state != ToPlainTextState.StartLine)
{
builder.AppendLine();
state = ToPlainTextState.StartLine;
}
Plain(builder, ref state, element.Nodes());
if (state != ToPlainTextState.StartLine)
{
builder.AppendLine();
state = ToPlainTextState.StartLine;
}
}
}
else if (node is XText)
{
var text = (XText)node;
Process(builder, ref state, text.Value.ToCharArray());
}
}
}
private static void Plain(StringBuilder builder, ref ToPlainTextState state, IEnumerable <HtmlAgilityPack.HtmlNode> nodes)
{
foreach (var node in nodes)
{
if (node is HtmlAgilityPack.HtmlTextNode)
{
var text = (HtmlAgilityPack.HtmlTextNode)node;
Process(builder, ref state, HtmlAgilityPack.HtmlEntity.DeEntitize(text.Text).ToCharArray());
}
else
{
var tag = node.Name.ToLower();
if (tag == "br")
{
builder.AppendLine();
state = ToPlainTextState.StartLine;
}
else if (NonVisibleTags.Contains(tag))
{
}
else if (InlineTags.Contains(tag))
{
Plain(builder, ref state, node.ChildNodes);
}
else
{
if (state != ToPlainTextState.StartLine)
{
builder.AppendLine();
state = ToPlainTextState.StartLine;
}
Plain(builder, ref state, node.ChildNodes);
if (state != ToPlainTextState.StartLine)
{
builder.AppendLine();
state = ToPlainTextState.StartLine;
}
}
}
}
}
private static void Plain(StringBuilder builder, ref ToPlainTextState state, IEnumerable <HtmlNode> nodes)
{
foreach (HtmlNode node in nodes)
{
if (node is HtmlTextNode)
{
HtmlTextNode text = (HtmlTextNode)node;
char[] chars = HtmlEntity.DeEntitize(text.Text).ToCharArray();
foreach (char ch in chars)
{
if (char.IsWhiteSpace(ch))
{
if (ch == 0xA0 || ch == 0x2007 || ch == 0x202F)
{
if (state == ToPlainTextState.WhiteSpace)
{
builder.Append(' ');
}
builder.Append(' ');
state = ToPlainTextState.NotWhiteSpace;
}
else
{
if (state == ToPlainTextState.NotWhiteSpace)
{
state = ToPlainTextState.WhiteSpace;
}
}
}
else
{
if (state == ToPlainTextState.WhiteSpace)
{
builder.Append(' ');
}
builder.Append(ch);
state = ToPlainTextState.NotWhiteSpace;
}
}
}
else
{
string tag = node.Name.ToLower();
if (tag == "br")
{
builder.AppendLine();
state = ToPlainTextState.StartLine;
}
else if (NonVisibleTags.Contains(tag))
{
}
else if (InlineTags.Contains(tag))
{
Plain(builder, ref state, node.ChildNodes);
}
else
{
if (state != ToPlainTextState.StartLine)
{
builder.AppendLine();
state = ToPlainTextState.StartLine;
}
Plain(builder, ref state, node.ChildNodes);
if (state != ToPlainTextState.StartLine)
{
builder.AppendLine();
state = ToPlainTextState.StartLine;
}
}
}
}
}