private async ValueTask <bool> FoldClosingTagsAsync(List <Node> nodes)
{
for (var j = nodes.Count - 1; j >= 0; j--)
{
if (nodes[j] is Shortcode end && end.Style == ShortcodeStyle.Close)
{
// Found an end tag
for (var i = 0; i < j; i++)
{
if (nodes[i] is Shortcode start && start.Style == ShortcodeStyle.Open && String.Equals(start.Identifier, end.Identifier, StringComparison.OrdinalIgnoreCase))
{
var text = "";
// Don't instantiate a builder if there is no inner node
if (i < j - 1)
{
using (var sb = StringBuilderPool.GetInstance())
{
for (var k = i + 1; k < j; k++)
{
sb.Builder.Append(await RenderAsync(nodes[k]));
}
text = sb.ToString();
}
}
nodes.RemoveRange(i + 1, j - i);
start.Content = text;
return(true);
}
}
}
}
return(false);
}
private async ValueTask <string> FoldClosingTagsAsync(string input, List <Node> nodes, int index, int length, Context context)
{
// This method should not be called when nodes has a single RawText element.
// It's implementation assumes at least two nodes are provided.
using var sb = StringBuilderPool.GetInstance();
// The index of the next shortcode opening node
var cursor = index;
// Process the list
while (cursor <= index + length - 1)
{
Shortcode start = null;
var head = 0;
var tail = 0;
// Find the next opening tag
while (cursor <= index + length - 1 && start == null)
{
var node = nodes[cursor];
if (node is Shortcode shortCode)
{
if (shortCode.Style == ShortcodeStyle.Open)
{
head = cursor;
start = shortCode;
}
else
{
// These closing tags need to be rendered
sb.Builder.Append(input, shortCode.SourceIndex, shortCode.SourceLength + 1);
}
}
else
{
var text = node as RawText;
sb.Builder.Append(text.Buffer, text.Offset, text.Count);
}
cursor += 1;
}
// if start is null, then there is nothing to fold
if (start == null)
{
return(sb.Builder.ToString());
}
Shortcode end = null;
var depth = 1;
// Find a matching closing tag
while (cursor <= index + length - 1 && end == null)
{
if (nodes[cursor] is Shortcode shortCode)
{
if (String.Equals(start.Identifier, shortCode.Identifier, StringComparison.OrdinalIgnoreCase))
{
if (shortCode.Style == ShortcodeStyle.Open)
{
// We need to count all opening shortcodes matching the start to account for:
// [a] [a] [/a] [/a]
depth += 1;
}
else
{
depth -= 1;
if (depth == 0)
{
tail = cursor;
end = shortCode;
}
}
}
}
cursor += 1;
}
// Is it a single tag?
if (end == null)
{
cursor = head + 1;
// If there are more than one open/close brace we don't evaluate the shortcode
if (start.OpenBraces > 1 || start.CloseBraces > 1)
{
// We need to escape the braces if counts match
var bracesToSkip = start.OpenBraces == start.CloseBraces ? 1 : 0;
sb.Builder.Append('[', start.OpenBraces - bracesToSkip);
sb.Builder.Append(input, start.SourceIndex + start.OpenBraces, start.SourceLength - start.CloseBraces - start.OpenBraces + 1);
sb.Builder.Append(']', start.CloseBraces - bracesToSkip);
}
else
{
await AppendAsync(sb.Builder, input, start, null, context);
}
}
else
{
// Standard braces are made of 1 brace on each edge
var standardBraces = start.OpenBraces == 1 && start.CloseBraces == 1 && end.OpenBraces == 1 && end.CloseBraces == 1;
var balancedBraces = start.OpenBraces == end.CloseBraces && start.CloseBraces == end.OpenBraces;
if (standardBraces)
{
// Are the tags adjacent?
if (tail - head == 1)
{
start.Content = "";
await AppendAsync(sb.Builder, input, start, end, context);
}
// Is there a single node between the tags?
else if (tail - head == 2)
{
// Render the inner node (raw or shortcode)
var content = nodes[head + 1];
// Set it to the start shortcode
using (var sbContent = StringBuilderPool.GetInstance())
{
await AppendAsync(sbContent.Builder, input, content, null, context);
start.Content = sbContent.ToString();
}
// Render the start shortcode
await AppendAsync(sb.Builder, input, start, end, context);
}
// Fold the inner nodes
else
{
start.Content = await FoldClosingTagsAsync(input, nodes, head + 1, tail - head - 1, context);
await AppendAsync(sb.Builder, input, start, end, context);
}
}
else
{
// Balanced braces represent an escape sequence, e.g. [[upper]foo[/upper]] -> [upper]foo[/upper]
if (balancedBraces)
{
var bracesToSkip = start.OpenBraces == end.CloseBraces ? 1 : 0;
sb.Builder.Append('[', start.OpenBraces - bracesToSkip);
sb.Builder.Append(input, start.SourceIndex + start.OpenBraces, end.SourceIndex + end.SourceLength - end.CloseBraces - start.SourceIndex - start.OpenBraces + 1);
sb.Builder.Append(']', end.CloseBraces - bracesToSkip);
}
// Unbalanced braces only evaluate inner content, e.g. [upper]foo[/upper]]
else
{
// Are the tags adjacent?
if (tail - head == 1)
{
AppendRawNode(sb.Builder, input, start);
AppendRawNode(sb.Builder, input, end);
}
// Is there a single node between the tags?
else if (tail - head == 2)
{
// Render the inner node (raw or shortcode)
var content = nodes[head + 1];
AppendRawNode(sb.Builder, input, start);
await AppendAsync(sb.Builder, input, content, null, context);
AppendRawNode(sb.Builder, input, end);
}
// Fold the inner nodes
else
{
var content = await FoldClosingTagsAsync(input, nodes, head + 1, tail - head - 1, context);
AppendRawNode(sb.Builder, input, start);
sb.Builder.Append(content);
AppendRawNode(sb.Builder, input, end);
}
}
}
}
}
return(sb.Builder.ToString());
}
private async ValueTask <string> FoldClosingTagsAsync(string input, List <Node> nodes, int index, int length, Context context)
{
// This method should not be called when nodes has a single RawText element.
// It's implementation assumes at least two nodes are provided.
using var sb = StringBuilderPool.GetInstance();
// The index of the next shortcode opening node
var cursor = index;
// Process the list
while (cursor <= index + length - 1)
{
Shortcode start = null;
var head = 0;
var tail = 0;
// Find the next opening tag
while (cursor < nodes.Count && start == null)
{
var node = nodes[cursor];
if (node is Shortcode shortCode)
{
if (shortCode.Style == ShortcodeStyle.Open)
{
head = cursor;
start = shortCode;
}
}
else
{
var text = node as RawText;
sb.Builder.Append(text.Text);
}
cursor += 1;
}
// if start is null, then there is nothing to fold
if (start == null)
{
return(sb.Builder.ToString());
}
Shortcode end = null;
var depth = 1;
// Find a matching closing tag
while (cursor <= index + length - 1 && end == null)
{
if (nodes[cursor] is Shortcode shortCode)
{
if (String.Equals(start.Identifier, shortCode.Identifier, StringComparison.OrdinalIgnoreCase))
{
if (shortCode.Style == ShortcodeStyle.Open)
{
// We need to count all opening shortcodes matching the start to account for:
// [a] [a] [/a] [/a]
depth += 1;
}
else
{
depth -= 1;
if (depth == 0)
{
tail = cursor;
end = shortCode;
}
}
}
}
cursor += 1;
}
// Is is a single tag?
if (end == null)
{
cursor = head + 1;
// If there are more than one open/close brace we don't evaluate the shortcode
if (start.OpenBraces > 1 || start.CloseBraces > 1)
{
// We need to escape the braces if counts match
var bracesToSkip = start.OpenBraces == start.CloseBraces ? 1 : 0;
sb.Builder.Append('[', start.OpenBraces - bracesToSkip);
sb.Builder.Append(input.Substring(start.SourceIndex + start.OpenBraces, start.SourceLength - start.CloseBraces - start.OpenBraces + 1));
sb.Builder.Append(']', start.CloseBraces - bracesToSkip);
}
else
{
sb.Builder.Append(await RenderAsync(start, context));
}
}
else
{
// If the braces are unbalanced we can't render the shortcode
var canRenderShortcode = start.OpenBraces == 1 && start.CloseBraces == 1 && end.OpenBraces == 1 && end.CloseBraces == 1;
if (canRenderShortcode)
{
// Are the tags adjacent?
if (tail - head == 1)
{
start.Content = "";
sb.Builder.Append(await RenderAsync(start, context));
}
// Is there a single Raw text between the tags?
else if (tail - head == 2)
{
var content = nodes[head + 1] as RawText;
start.Content = content.Text;
sb.Builder.Append(await RenderAsync(start, context));
}
// Fold the inner nodes
else
{
var content = await FoldClosingTagsAsync(input, nodes, head + 1, tail - head - 1, context);
start.Content = content;
sb.Builder.Append(await RenderAsync(start, context));
}
}
else
{
var bracesToSkip = start.OpenBraces == end.CloseBraces ? 1 : 0;
sb.Builder.Append('[', start.OpenBraces - bracesToSkip);
sb.Builder.Append(input.Substring(start.SourceIndex + start.OpenBraces, end.SourceIndex + end.SourceLength - end.CloseBraces - start.SourceIndex - start.OpenBraces + 1));
sb.Builder.Append(']', end.CloseBraces - bracesToSkip);
}
}
}
return(sb.Builder.ToString());
}
