1 files changed, 151 insertions, 0 deletions
diff --git a/src/mistune/renderers/html.py b/src/mistune/renderers/html.py
new file mode 100644
index 0000000..c458a4a
--- /dev/null
+++ b/src/mistune/renderers/html.py
@@ -0,0 +1,151 @@
+from ..core import BaseRenderer
+from ..util import escape as escape_text, striptags, safe_entity
+
+
+class HTMLRenderer(BaseRenderer):
+    """A renderer for converting Markdown to HTML."""
+    NAME = 'html'
+    HARMFUL_PROTOCOLS = (
+        'javascript:',
+        'vbscript:',
+        'file:',
+        'data:',
+    )
+    GOOD_DATA_PROTOCOLS = (
+        'data:image/gif;',
+        'data:image/png;',
+        'data:image/jpeg;',
+        'data:image/webp;',
+    )
+
+    def __init__(self, escape=True, allow_harmful_protocols=None):
+        super(HTMLRenderer, self).__init__()
+        self._allow_harmful_protocols = allow_harmful_protocols
+        self._escape = escape
+
+    def render_token(self, token, state):
+        # backward compitable with v2
+        func = self._get_method(token['type'])
+        attrs = token.get('attrs')
+
+        if 'raw' in token:
+            text = token['raw']
+        elif 'children' in token:
+            text = self.render_tokens(token['children'], state)
+        else:
+            if attrs:
+                return func(**attrs)
+            else:
+                return func()
+        if attrs:
+            return func(text, **attrs)
+        else:
+            return func(text)
+
+    def safe_url(self, url: str) -> str:
+        """Ensure the given URL is safe. This method is used for rendering
+        links, images, and etc.
+        """
+        if self._allow_harmful_protocols is True:
+            return url
+
+        _url = url.lower()
+        if self._allow_harmful_protocols and \
+            _url.startswith(tuple(self._allow_harmful_protocols)):
+            return url
+
+        if _url.startswith(self.HARMFUL_PROTOCOLS) and \
+            not _url.startswith(self.GOOD_DATA_PROTOCOLS):
+            return '#harmful-link'
+        return url
+
+    def text(self, text: str) -> str:
+        if self._escape:
+            return escape_text(text)
+        return safe_entity(text)
+
+    def emphasis(self, text: str) -> str:
+        return '<em>' + text + '</em>'
+
+    def strong(self, text: str) -> str:
+        return '<strong>' + text + '</strong>'
+
+    def link(self, text: str, url: str, title=None) -> str:
+        s = '<a href="' + self.safe_url(url) + '"'
+        if title:
+            s += ' title="' + safe_entity(title) + '"'
+        return s + '>' + text + '</a>'
+
+    def image(self, text: str, url: str, title=None) -> str:
+        src = self.safe_url(url)
+        alt = escape_text(striptags(text))
+        s = '<img src="' + src + '" alt="' + alt + '"'
+        if title:
+            s += ' title="' + safe_entity(title) + '"'
+        return s + ' />'
+
+    def codespan(self, text: str) -> str:
+        return '<code>' + text + '</code>'
+
+    def linebreak(self) -> str:
+        return '<br />\n'
+
+    def softbreak(self) -> str:
+        return '\n'
+
+    def inline_html(self, html: str) -> str:
+        if self._escape:
+            return escape_text(html)
+        return html
+
+    def paragraph(self, text: str) -> str:
+        return '<p>' + text + '</p>\n'
+
+    def heading(self, text: str, level: int, **attrs) -> str:
+        tag = 'h' + str(level)
+        html = '<' + tag
+        _id = attrs.get('id')
+        if _id:
+            html += ' id="' + _id + '"'
+        return html + '>' + text + '</' + tag + '>\n'
+
+    def blank_line(self) -> str:
+        return ''
+
+    def thematic_break(self) -> str:
+        return '<hr />\n'
+
+    def block_text(self, text: str) -> str:
+        return text
+
+    def block_code(self, code: str, info=None) -> str:
+        html = '<pre><code'
+        if info is not None:
+            info = safe_entity(info.strip())
+        if info:
+            lang = info.split(None, 1)[0]
+            html += ' class="language-' + lang + '"'
+        return html + '>' + escape_text(code) + '</code></pre>\n'
+
+    def block_quote(self, text: str) -> str:
+        return '<blockquote>\n' + text + '</blockquote>\n'
+
+    def block_html(self, html: str) -> str:
+        if self._escape:
+            return '<p>' + escape_text(html) + '</p>\n'
+        return html + '\n'
+
+    def block_error(self, text: str) -> str:
+        return '<div class="error"><pre>' + text + '</pre></div>\n'
+
+    def list(self, text: str, ordered: bool, **attrs) -> str:
+        if ordered:
+            html = '<ol'
+            start = attrs.get('start')
+            if start is not None:
+                html += ' start="' + str(start) + '"'
+            return html + '>\n' + text + '</ol>\n'
+        return '<ul>\n' + text + '</ul>\n'
+
+    def list_item(self, text: str) -> str:
+        return '<li>' + text + '</li>\n'