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