1 files changed, 80 insertions, 0 deletions
diff --git a/src/mistune/plugins/spoiler.py b/src/mistune/plugins/spoiler.py
new file mode 100644
index 0000000..2931d2b
--- /dev/null
+++ b/src/mistune/plugins/spoiler.py
@@ -0,0 +1,80 @@
+import re
+
+__all__ = ['spoiler']
+
+_BLOCK_SPOILER_START = re.compile(r'^ {0,3}! ?', re.M)
+_BLOCK_SPOILER_MATCH = re.compile(r'^( {0,3}![^\n]*\n)+$')
+
+INLINE_SPOILER_PATTERN = r'>!\s*(?P<spoiler_text>.+?)\s*!<'
+
+
+def parse_block_spoiler(block, m, state):
+    text, end_pos = block.extract_block_quote(m, state)
+    if not text.endswith('\n'):
+        # ensure it endswith \n to make sure
+        # _BLOCK_SPOILER_MATCH.match works
+        text += '\n'
+
+    depth = state.depth()
+    if not depth and _BLOCK_SPOILER_MATCH.match(text):
+        text = _BLOCK_SPOILER_START.sub('', text)
+        tok_type = 'block_spoiler'
+    else:
+        tok_type = 'block_quote'
+
+    # scan children state
+    child = state.child_state(text)
+    if state.depth() >= block.max_nested_level - 1:
+        rules = list(block.block_quote_rules)
+        rules.remove('block_quote')
+    else:
+        rules = block.block_quote_rules
+
+    block.parse(child, rules)
+    token = {'type': tok_type, 'children': child.tokens}
+    if end_pos:
+        state.prepend_token(token)
+        return end_pos
+    state.append_token(token)
+    return state.cursor
+
+
+def parse_inline_spoiler(inline, m, state):
+    text = m.group('spoiler_text')
+    new_state = state.copy()
+    new_state.src = text
+    children = inline.render(new_state)
+    state.append_token({'type': 'inline_spoiler', 'children': children})
+    return m.end()
+
+
+def render_block_spoiler(renderer, text):
+    return '<div class="spoiler">\n' + text + '</div>\n'
+
+
+def render_inline_spoiler(renderer, text):
+    return '<span class="spoiler">' + text + '</span>'
+
+
+def spoiler(md):
+    """A mistune plugin to support block and inline spoiler. The
+    syntax is inspired by stackexchange:
+
+    .. code-block:: text
+
+        Block level spoiler looks like block quote, but with `>!`:
+
+        >! this is spoiler
+        >!
+        >! the content will be hidden
+
+        Inline spoiler is surrounded by `>!` and `!<`, such as >! hide me !<.
+
+    :param md: Markdown instance
+    """
+    # reset block quote parser with block spoiler parser
+    md.block.register('block_quote', None, parse_block_spoiler)
+    md.inline.register('inline_spoiler', INLINE_SPOILER_PATTERN, parse_inline_spoiler)
+    if md.renderer and md.renderer.NAME == 'html':
+        md.renderer.register('block_spoiler', render_block_spoiler)
+        md.renderer.register('inline_spoiler', render_inline_spoiler)