1 files changed, 105 insertions, 0 deletions
diff --git a/src/mistune/directives/toc.py b/src/mistune/directives/toc.py
new file mode 100644
index 0000000..4084f43
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+++ b/src/mistune/directives/toc.py
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+"""
+    TOC directive
+    ~~~~~~~~~~~~~
+
+    The TOC directive syntax looks like::
+
+        .. toc:: Title
+           :min-level: 1
+           :max-level: 3
+
+    "Title", "min-level", and "max-level" option can be empty. "min-level"
+    and "max-level" are integers >= 1 and <= 6, which define the allowed
+    heading levels writers want to include in the table of contents.
+"""
+
+from ._base import DirectivePlugin
+from ..toc import normalize_toc_item, render_toc_ul
+
+
+class TableOfContents(DirectivePlugin):
+    def __init__(self, min_level=1, max_level=3):
+        self.min_level = min_level
+        self.max_level = max_level
+
+    def generate_heading_id(self, token, index):
+        return 'toc_' + str(index + 1)
+
+    def parse(self, block, m, state):
+        title = self.parse_title(m)
+        options = self.parse_options(m)
+        if options:
+            d_options = dict(options)
+            collapse = 'collapse' in d_options
+            min_level = _normalize_level(d_options, 'min-level', self.min_level)
+            max_level = _normalize_level(d_options, 'max-level', self.max_level)
+            if min_level < self.min_level:
+                raise ValueError(f'"min-level" option MUST be >= {self.min_level}')
+            if max_level > self.max_level:
+                raise ValueError(f'"max-level" option MUST be <= {self.max_level}')
+            if min_level > max_level:
+                raise ValueError('"min-level" option MUST be less than "max-level" option')
+        else:
+            collapse = False
+            min_level = self.min_level
+            max_level = self.max_level
+
+        attrs = {
+            'min_level': min_level,
+            'max_level': max_level,
+            'collapse': collapse,
+        }
+        return {'type': 'toc', 'text': title or '', 'attrs': attrs}
+
+    def toc_hook(self, md, state):
+        sections = []
+        headings = []
+
+        for tok in state.tokens:
+            if tok['type'] == 'toc':
+                sections.append(tok)
+            elif tok['type'] == 'heading':
+                headings.append(tok)
+
+        if sections:
+            toc_items = []
+            # adding ID for each heading
+            for i, tok in enumerate(headings):
+                tok['attrs']['id'] = self.generate_heading_id(tok, i)
+                toc_items.append(normalize_toc_item(md, tok))
+
+            for sec in sections:
+                _min = sec['attrs']['min_level']
+                _max = sec['attrs']['max_level']
+                toc = [item for item in toc_items if _min <= item[0] <= _max]
+                sec['attrs']['toc'] = toc
+
+    def __call__(self, directive, md):
+        if md.renderer and md.renderer.NAME == 'html':
+            # only works with HTML renderer
+            directive.register('toc', self.parse)
+            md.before_render_hooks.append(self.toc_hook)
+            md.renderer.register('toc', render_html_toc)
+
+
+def render_html_toc(renderer, title, collapse=False, **attrs):
+    if not title:
+        title = 'Table of Contents'
+    toc = attrs['toc']
+    content = render_toc_ul(attrs['toc'])
+
+    html = '<details class="toc"'
+    if not collapse:
+        html += ' open'
+    html += '>\n<summary>' + title + '</summary>\n'
+    return html + content + '</details>\n'
+
+
+def _normalize_level(options, name, default):
+    level = options.get(name)
+    if not level:
+        return default
+    try:
+        return int(level)
+    except (ValueError, TypeError):
+        raise ValueError(f'"{name}" option MUST be integer')