/// <summary>Initializes a new instance of the <see cref="HtmlFormatter" /> class.</summary>
/// <param name="target">The target text writer.</param>
/// <param name="settings">The settings used when formatting the data.</param>
/// <exception cref="ArgumentNullException">when <paramref name="target"/> is <see langword="null"/></exception>
public HtmlFormatter(TextWriter target, CommonMarkSettings settings)
{
if (target == null)
throw new ArgumentNullException(nameof(target));
if (settings == null)
settings = CommonMarkSettings.Default;
_target = new HtmlTextWriter(target);
_settings = settings;
}
/// <summary>
/// Escapes special URL characters.
/// </summary>
/// <remarks>Orig: escape_html(inp, preserve_entities)</remarks>
internal static void EscapeUrl(string input, HtmlTextWriter target) {
if (input == null)
return;
char c;
int lastPos = 0;
int len = input.Length;
char[] buffer;
if (target.Buffer.Length < len)
buffer = target.Buffer = input.ToCharArray();
else {
buffer = target.Buffer;
input.CopyTo(0, buffer, 0, len);
}
// since both \r and \n are not url-safe characters and will be encoded, all calls are
// made to WriteConstant.
for (var pos = 0; pos < len; pos++) {
c = buffer[pos];
if (c == '&') {
target.WriteConstant(buffer, lastPos, pos - lastPos);
lastPos = pos + 1;
target.WriteConstant(EscapeHtmlAmpersand);
} else if (c < 128 && !UrlSafeCharacters[c]) {
target.WriteConstant(buffer, lastPos, pos - lastPos);
lastPos = pos + 1;
target.WriteConstant(new[] { '%', HexCharacters[c / 16], HexCharacters[c % 16] });
} else if (c > 127) {
target.WriteConstant(buffer, lastPos, pos - lastPos);
lastPos = pos + 1;
byte[] bytes;
if (c >= '\ud800' && c <= '\udfff' && len != lastPos) {
// this char is the first of UTF-32 character pair
bytes = Encoding.UTF8.GetBytes(new[] { c, buffer[lastPos] });
lastPos = ++pos + 1;
} else {
bytes = Encoding.UTF8.GetBytes(new[] { c });
}
for (var i = 0; i < bytes.Length; i++)
target.WriteConstant(new[] { '%', HexCharacters[bytes[i] / 16], HexCharacters[bytes[i] % 16] });
}
}
target.WriteConstant(buffer, lastPos, len - lastPos);
}
/// <summary>
/// Writes the inline list to the given writer as HTML code.
/// </summary>
private static void InlinesToHtml(HtmlTextWriter writer, Inline inline, CommonMarkSettings settings, Stack<InlineStackEntry> stack)
{
var uriResolver = settings.UriResolver;
bool withinLink = false;
bool stackWithinLink = false;
bool visitChildren;
bool trackPositions = settings.TrackSourcePosition;
string stackLiteral = null;
while (inline != null)
{
visitChildren = false;
switch (inline.Tag)
{
case InlineTag.String:
if (trackPositions)
{
writer.WriteConstant("<span");
PrintPosition(writer, inline);
writer.Write('>');
EscapeHtml(inline.LiteralContentValue, writer);
writer.WriteConstant("</span>");
}
else
{
EscapeHtml(inline.LiteralContentValue, writer);
}
break;
case InlineTag.LineBreak:
writer.WriteLineConstant("<br />");
break;
case InlineTag.SoftBreak:
if (settings.RenderSoftLineBreaksAsLineBreaks)
writer.WriteLineConstant("<br />");
else
writer.WriteLine();
break;
case InlineTag.Code:
writer.WriteConstant("<code");
if (trackPositions) PrintPosition(writer, inline);
writer.Write('>');
EscapeHtml(inline.LiteralContentValue, writer);
writer.WriteConstant("</code>");
break;
case InlineTag.RawHtml:
// cannot output source position for HTML blocks
writer.Write(inline.LiteralContentValue);
break;
case InlineTag.Link:
if (withinLink)
{
writer.Write('[');
stackLiteral = "]";
stackWithinLink = true;
visitChildren = true;
}
else
{
writer.WriteConstant("<a href=\"");
if (uriResolver != null)
EscapeUrl(uriResolver(inline.TargetUrl), writer);
else
EscapeUrl(inline.TargetUrl, writer);
writer.Write('\"');
if (inline.LiteralContentValue.Length > 0)
{
writer.WriteConstant(" title=\"");
EscapeHtml(inline.LiteralContentValue, writer);
writer.Write('\"');
}
if (trackPositions) PrintPosition(writer, inline);
writer.Write('>');
visitChildren = true;
stackWithinLink = true;
stackLiteral = "</a>";
}
break;
case InlineTag.Image:
writer.WriteConstant("<img src=\"");
if (uriResolver != null)
EscapeUrl(uriResolver(inline.TargetUrl), writer);
else
EscapeUrl(inline.TargetUrl, writer);
writer.WriteConstant("\" alt=\"");
InlinesToPlainText(writer, inline.FirstChild, stack);
writer.Write('\"');
if (inline.LiteralContentValue.Length > 0)
{
writer.WriteConstant(" title=\"");
EscapeHtml(inline.LiteralContentValue, writer);
writer.Write('\"');
}
if (trackPositions) PrintPosition(writer, inline);
writer.WriteConstant(" />");
break;
case InlineTag.Strong:
writer.WriteConstant("<strong");
if (trackPositions) PrintPosition(writer, inline);
writer.Write('>');
stackLiteral = "</strong>";
stackWithinLink = withinLink;
visitChildren = true;
break;
case InlineTag.Emphasis:
writer.WriteConstant("<em");
if (trackPositions) PrintPosition(writer, inline);
writer.Write('>');
stackLiteral = "</em>";
visitChildren = true;
stackWithinLink = withinLink;
break;
case InlineTag.Strikethrough:
writer.WriteConstant("<del");
if (trackPositions) PrintPosition(writer, inline);
writer.Write('>');
stackLiteral = "</del>";
visitChildren = true;
stackWithinLink = withinLink;
break;
default:
throw new CommonMarkException("Inline type " + inline.Tag + " is not supported.", inline);
}
if (visitChildren)
{
stack.Push(new InlineStackEntry(stackLiteral, inline.NextSibling, withinLink));
withinLink = stackWithinLink;
inline = inline.FirstChild;
}
else if (inline.NextSibling != null)
{
inline = inline.NextSibling;
}
else
{
inline = null;
}
while (inline == null && stack.Count > 0)
{
var entry = stack.Pop();
writer.WriteConstant(entry.Literal);
inline = entry.Target;
withinLink = entry.IsWithinLink;
}
}
}
/// <summary>
/// Writes the inline list to the given writer as plain text (without any HTML tags).
/// </summary>
/// <seealso href="https://github.com/jgm/CommonMark/issues/145"/>
private static void InlinesToPlainText(HtmlTextWriter writer, Inline inline, Stack<InlineStackEntry> stack)
{
bool withinLink = false;
bool stackWithinLink = false;
bool visitChildren;
string stackLiteral = null;
var origStackCount = stack.Count;
while (inline != null)
{
visitChildren = false;
switch (inline.Tag)
{
case InlineTag.String:
case InlineTag.Code:
case InlineTag.RawHtml:
EscapeHtml(inline.LiteralContentValue, writer);
break;
case InlineTag.LineBreak:
case InlineTag.SoftBreak:
writer.WriteLine();
break;
case InlineTag.Link:
if (withinLink)
{
writer.Write('[');
stackLiteral = "]";
visitChildren = true;
stackWithinLink = true;
}
else
{
visitChildren = true;
stackWithinLink = true;
stackLiteral = string.Empty;
}
break;
case InlineTag.Image:
visitChildren = true;
stackWithinLink = true;
stackLiteral = string.Empty;
break;
case InlineTag.Strong:
case InlineTag.Emphasis:
case InlineTag.Strikethrough:
stackLiteral = string.Empty;
stackWithinLink = withinLink;
visitChildren = true;
break;
default:
throw new CommonMarkException("Inline type " + inline.Tag + " is not supported.", inline);
}
if (visitChildren)
{
stack.Push(new InlineStackEntry(stackLiteral, inline.NextSibling, withinLink));
withinLink = stackWithinLink;
inline = inline.FirstChild;
}
else if (inline.NextSibling != null)
{
inline = inline.NextSibling;
}
else
{
inline = null;
}
while (inline == null && stack.Count > origStackCount)
{
var entry = stack.Pop();
writer.WriteConstant(entry.Literal);
inline = entry.Target;
withinLink = entry.IsWithinLink;
}
}
}
private static void BlocksToHtmlInner(HtmlTextWriter writer, Block block, CommonMarkSettings settings)
{
var stack = new Stack<BlockStackEntry>();
var inlineStack = new Stack<InlineStackEntry>();
bool visitChildren;
string stackLiteral = null;
bool stackTight = false;
bool tight = false;
bool trackPositions = settings.TrackSourcePosition;
int x;
while (block != null)
{
visitChildren = false;
switch (block.Tag)
{
case BlockTag.Document:
stackLiteral = null;
stackTight = false;
visitChildren = true;
break;
case BlockTag.Paragraph:
if (tight)
{
InlinesToHtml(writer, block.InlineContent, settings, inlineStack);
}
else
{
writer.EnsureLine();
writer.WriteConstant("<p");
if (trackPositions) PrintPosition(writer, block);
writer.Write('>');
InlinesToHtml(writer, block.InlineContent, settings, inlineStack);
writer.WriteLineConstant("</p>");
}
break;
case BlockTag.BlockQuote:
writer.EnsureLine();
writer.WriteConstant("<blockquote");
if (trackPositions) PrintPosition(writer, block);
writer.WriteLine('>');
stackLiteral = "</blockquote>";
stackTight = false;
visitChildren = true;
break;
case BlockTag.ListItem:
writer.EnsureLine();
writer.WriteConstant("<li");
if (trackPositions) PrintPosition(writer, block);
writer.Write('>');
stackLiteral = "</li>";
stackTight = tight;
visitChildren = true;
break;
case BlockTag.List:
// make sure a list starts at the beginning of the line:
writer.EnsureLine();
var data = block.ListData;
writer.WriteConstant(data.ListType == ListType.Bullet ? "<ul" : "<ol");
if (data.Start != 1)
{
writer.WriteConstant(" start=\"");
writer.WriteConstant(data.Start.ToString(CultureInfo.InvariantCulture));
writer.Write('\"');
}
if (trackPositions) PrintPosition(writer, block);
writer.WriteLine('>');
stackLiteral = data.ListType == ListType.Bullet ? "</ul>" : "</ol>";
stackTight = data.IsTight;
visitChildren = true;
break;
case BlockTag.AtxHeader:
case BlockTag.SETextHeader:
writer.EnsureLine();
x = block.HeaderLevel;
if (trackPositions)
{
writer.WriteConstant("<h" + x.ToString(CultureInfo.InvariantCulture));
PrintPosition(writer, block);
writer.Write('>');
InlinesToHtml(writer, block.InlineContent, settings, inlineStack);
writer.WriteLineConstant(x > 0 && x < 7 ? HeaderCloserTags[x - 1] : "</h" + x.ToString(CultureInfo.InvariantCulture) + ">");
}
else
{
writer.WriteConstant(x > 0 && x < 7 ? HeaderOpenerTags[x - 1] : "<h" + x.ToString(CultureInfo.InvariantCulture) + ">");
InlinesToHtml(writer, block.InlineContent, settings, inlineStack);
writer.WriteLineConstant(x > 0 && x < 7 ? HeaderCloserTags[x - 1] : "</h" + x.ToString(CultureInfo.InvariantCulture) + ">");
}
break;
case BlockTag.IndentedCode:
case BlockTag.FencedCode:
writer.EnsureLine();
writer.WriteConstant("<pre><code");
if (trackPositions) PrintPosition(writer, block);
var info = block.FencedCodeData == null ? null : block.FencedCodeData.Info;
if (info != null && info.Length > 0)
{
x = info.IndexOf(' ');
if (x == -1)
x = info.Length;
writer.WriteConstant(" class=\"language-");
EscapeHtml(new StringPart(info, 0, x), writer);
writer.Write('\"');
}
writer.Write('>');
EscapeHtml(block.StringContent, writer);
writer.WriteLineConstant("</code></pre>");
break;
case BlockTag.HtmlBlock:
// cannot output source position for HTML blocks
block.StringContent.WriteTo(writer);
break;
case BlockTag.HorizontalRuler:
if (trackPositions)
{
writer.WriteConstant("<hr");
PrintPosition(writer, block);
writer.WriteLine();
}
else
{
writer.WriteLineConstant("<hr />");
}
break;
case BlockTag.ReferenceDefinition:
break;
default:
throw new CommonMarkException("Block type " + block.Tag + " is not supported.", block);
}
if (visitChildren)
{
stack.Push(new BlockStackEntry(stackLiteral, block.NextSibling, tight));
tight = stackTight;
block = block.FirstChild;
}
else if (block.NextSibling != null)
{
block = block.NextSibling;
}
else
{
block = null;
}
while (block == null && stack.Count > 0)
{
var entry = stack.Pop();
writer.WriteLineConstant(entry.Literal);
tight = entry.IsTight;
block = entry.Target;
}
}
}
internal static void PrintPosition(HtmlTextWriter writer, Inline inline)
{
writer.WriteConstant(" data-sourcepos=\"");
writer.WriteConstant(inline.SourcePosition.ToString(CultureInfo.InvariantCulture));
writer.Write('-');
writer.WriteConstant(inline.SourceLastPosition.ToString(CultureInfo.InvariantCulture));
writer.WriteConstant("\"");
}
public static void BlocksToHtml(TextWriter writer, Block block, CommonMarkSettings settings)
{
var wrapper = new HtmlTextWriter(writer);
BlocksToHtmlInner(wrapper, block, settings);
}
/// <summary>
/// Escapes special HTML characters.
/// </summary>
/// <remarks>Orig: escape_html(inp, preserve_entities)</remarks>
internal static void EscapeHtml(StringContent inp, HtmlTextWriter target)
{
int pos;
int lastPos;
char[] buffer = target.Buffer;
var parts = inp.RetrieveParts();
for (var i = parts.Offset; i < parts.Offset + parts.Count; i++)
{
var part = parts.Array[i];
if (buffer.Length < part.Length)
buffer = target.Buffer = new char[part.Length];
part.Source.CopyTo(part.StartIndex, buffer, 0, part.Length);
lastPos = part.StartIndex;
while ((pos = part.Source.IndexOfAny(EscapeHtmlCharacters, lastPos, part.Length - lastPos + part.StartIndex)) != -1)
{
target.Write(buffer, lastPos - part.StartIndex, pos - lastPos);
lastPos = pos + 1;
switch (part.Source[pos])
{
case '<':
target.WriteConstant(EscapeHtmlLessThan);
break;
case '>':
target.WriteConstant(EscapeHtmlGreaterThan);
break;
case '&':
target.WriteConstant(EscapeHtmlAmpersand);
break;
case '"':
target.WriteConstant(EscapeHtmlQuote);
break;
}
}
target.Write(buffer, lastPos - part.StartIndex, part.Length - lastPos + part.StartIndex);
}
}
/// <summary>
/// Escapes special HTML characters.
/// </summary>
/// <remarks>Orig: escape_html(inp, preserve_entities)</remarks>
internal static void EscapeHtml(StringPart input, HtmlTextWriter target)
{
if (input.Length == 0)
return;
int pos;
int lastPos = input.StartIndex;
char[] buffer;
if (target.Buffer.Length < input.Length)
buffer = target.Buffer = new char[input.Length];
else
buffer = target.Buffer;
input.Source.CopyTo(input.StartIndex, buffer, 0, input.Length);
while ((pos = input.Source.IndexOfAny(EscapeHtmlCharacters, lastPos, input.Length - lastPos + input.StartIndex)) != -1)
{
target.Write(buffer, lastPos - input.StartIndex, pos - lastPos);
lastPos = pos + 1;
switch (input.Source[pos])
{
case '<':
target.WriteConstant(EscapeHtmlLessThan);
break;
case '>':
target.WriteConstant(EscapeHtmlGreaterThan);
break;
case '&':
target.WriteConstant(EscapeHtmlAmpersand);
break;
case '"':
target.WriteConstant(EscapeHtmlQuote);
break;
}
}
target.Write(buffer, lastPos - input.StartIndex, input.Length - lastPos + input.StartIndex);
}
internal static void PrintPosition(HtmlTextWriter writer, Inline inline) {
writer.WriteConstant(" lmo=\"");
writer.WriteConstant((inline.SourcePosition).ToString(CultureInfo.InvariantCulture));
writer.WriteConstant("\" lmc=\"");
writer.WriteConstant((inline.SourceLastPosition).ToString(CultureInfo.InvariantCulture));
writer.WriteConstant("\"");
}
internal static void PrintPosition(HtmlTextWriter writer, Block block) {
//LM
writer.WriteConstant(" lmo=\"");
writer.WriteConstant((block.SourcePosition).ToString(CultureInfo.InvariantCulture));
writer.WriteConstant("\" lmc=\"");
writer.WriteConstant((block.SourceLastPosition).ToString(CultureInfo.InvariantCulture));
writer.WriteConstant("\"");
}
private void WriteGitHubHeadingIds(HtmlTextWriter writer, Inline inline, CommonMarkSettings settings, Stack<InlineStackEntry> stack) {
using (var tempWriter = new System.IO.StringWriter()) {
var tempWrapper = new HtmlTextWriter(tempWriter);
var tempStringBuilder = new StringBuilder();
InlinesToPlainText(tempWrapper, inline, stack);
string plaintextContent = tempWriter.ToString();
// Normalize plaintext content according to GitHub ID rules
plaintextContent = new Regex(@"[^\w\-\ ]").Replace(plaintextContent, "").Replace(" ", "-");
for (int c = 0; c < plaintextContent.Length; c++) {
if (plaintextContent[c] >= 'A' && plaintextContent[c] <= 'Z')
tempStringBuilder.Append((char)(plaintextContent[c] + 32));
else
tempStringBuilder.Append(plaintextContent[c]);
}
plaintextContent = tempStringBuilder.ToString();
string unique = "";
if (GitHubHeaderIdCounts.ContainsKey(plaintextContent))
unique = "-" + ++GitHubHeaderIdCounts[plaintextContent];
else
GitHubHeaderIdCounts[plaintextContent] = 0;
writer.WriteConstant(string.Format(@"<a id=""user-content-{0}{1}"" class=""anchor"" href=""#user-content-{0}{1}"" aria-hidden=""true""><svg class=""octicon octicon-link"" aria-hidden=""true"" height=""16"" role=""img"" version=""1.1"" viewBox=""0 0 16 16"" width=""16""><path d=""M4 9h1v1h-1c-1.5 0-3-1.69-3-3.5s1.55-3.5 3-3.5h4c1.45 0 3 1.69 3 3.5 0 1.41-0.91 2.72-2 3.25v-1.16c0.58-0.45 1-1.27 1-2.09 0-1.28-1.02-2.5-2-2.5H4c-0.98 0-2 1.22-2 2.5s1 2.5 2 2.5z m9-3h-1v1h1c1 0 2 1.22 2 2.5s-1.02 2.5-2 2.5H9c-0.98 0-2-1.22-2-2.5 0-0.83 0.42-1.64 1-2.09v-1.16c-1.09 0.53-2 1.84-2 3.25 0 1.81 1.55 3.5 3 3.5h4c1.45 0 3-1.69 3-3.5s-1.5-3.5-3-3.5z""></path></svg></a>",
plaintextContent, unique));
}
}
