👌 IMPROVE: Make link functions overridable (#135)

`validateLink`,  `normalizeLink` and `normalizeLinkText` are now methods of `MarkdownIt`,
meaning that they can be overriden by subclassing
`MarkdownIt`.

Author: chrisjsewell

markdown_it/common/normalize_url.py

@@ -67,7 +67,7 @@ def unescape_normalize_uri(x: str) -> str:
     return normalize_uri(unescape_string(x))
 
 
-def normalizeLink(url):
+def normalizeLink(url: str) -> str:
     """Normalize destination URLs in links
 
     ::
@@ -117,7 +117,7 @@ def unescape_unquote(x: str) -> str:
     return unquote(unescape_string(x))
 
 
-def normalizeLinkText(link):
+def normalizeLinkText(link: str) -> str:
     """Normalize autolink content
 
     ::
@@ -172,9 +172,6 @@ def validateLink(url: str, validator: Optional[Callable] = None) -> bool:
     This validator can prohibit more than really needed to prevent XSS.
     It's a tradeoff to keep code simple and to be secure by default.
 
-    If you need different setup - override validator method as you wish.
-    Or replace it with dummy function and use external sanitizer.
-
     Note: url should be normalized at this point, and existing entities decoded.
     """
     if validator is not None:

markdown_it/main.py

@@ -12,7 +12,7 @@
 )
 
 from . import helpers, presets  # noqa F401
-from .common import utils  # noqa F401
+from .common import normalize_url, utils  # noqa F401
 from .token import Token
 from .parser_core import ParserCore  # noqa F401
 from .parser_block import ParserBlock  # noqa F401
@@ -288,3 +288,35 @@ def renderInline(self, src: str, env: Optional[AttrDict] = None) -> Any:
         """
         env = AttrDict() if env is None else env
         return self.renderer.render(self.parseInline(src, env), self.options, env)
+
+    # link methods
+
+    def validateLink(self, url: str) -> bool:
+        """Validate if the URL link is allowed in output.
+
+        This validator can prohibit more than really needed to prevent XSS.
+        It's a tradeoff to keep code simple and to be secure by default.
+
+        Note: the url should be normalized at this point, and existing entities decoded.
+        """
+        return normalize_url.validateLink(url)
+
+    def normalizeLink(self, url: str) -> str:
+        """Normalize destination URLs in links
+
+        ::
+
+            [label]:   destination   'title'
+                    ^^^^^^^^^^^
+        """
+        return normalize_url.normalizeLink(url)
+
+    def normalizeLinkText(self, link: str) -> str:
+        """Normalize autolink content
+
+        ::
+
+            <destination>
+            ~~~~~~~~~~~
+        """
+        return normalize_url.normalizeLinkText(link)

markdown_it/port.yaml

@@ -19,16 +19,6 @@
       Use python's built-in `html.escape` and `urlparse.quote` methods, as a replacement for
       the JS dependencies [mdurl](https://www.npmjs.com/package/mdurl)
       and [punycode](https://www.npmjs.com/package/punycode)
-    - |
-      Remove indirect references within `MarkdownIt`;
-
-        self.validateLink = validateLink
-        self.normalizeLink = normalizeLink
-        self.normalizeLinkText = normalizeLinkText
-
-      in favour of using them directly through:
-
-        from markdown_it.common.normalize_url import normalizeLinkText
     - |
       In markdown_it/rules_block/reference.py,
       record line range in state.env["references"] and add state.env["duplicate_refs"]

markdown_it/rules_block/reference.py

@@ -1,7 +1,6 @@
 import logging
 
 from ..common.utils import isSpace, normalizeReference, charCodeAt
-from ..common.normalize_url import normalizeLink, validateLink
 from ..utils import AttrDict
 from .state_block import StateBlock
 
@@ -115,8 +114,8 @@ def reference(state: StateBlock, startLine, _endLine, silent):
     if not res.ok:
         return False
 
-    href = normalizeLink(res.str)
-    if not validateLink(href):
+    href = state.md.normalizeLink(res.str)
+    if not state.md.validateLink(href):
         return False
 
     pos = res.pos

markdown_it/rules_block/state_block.py

@@ -1,15 +1,18 @@
-from typing import List, Optional, Tuple
+from typing import List, Optional, Tuple, TYPE_CHECKING
 
 from ..token import Token
 from ..ruler import StateBase
 from ..common.utils import isSpace
 
+if TYPE_CHECKING:
+    from markdown_it.main import MarkdownIt
+
 
 class StateBlock(StateBase):
     def __init__(
         self,
         src: str,
-        md,
+        md: "MarkdownIt",
         env,
         tokens: List[Token],
         srcCharCode: Optional[Tuple[int, ...]] = None,

markdown_it/rules_core/linkify.py

@@ -1,7 +1,6 @@
 import re
 
 from ..common.utils import arrayReplaceAt
-from ..common.normalize_url import normalizeLinkText, normalizeLink, validateLink
 from .state_core import StateCore
 from ..token import Token
 
@@ -82,8 +81,8 @@ def linkify(state: StateCore) -> None:
 
                 for ln in range(len(links)):
                     url = links[ln].url
-                    fullUrl = normalizeLink(url)
-                    if not validateLink(fullUrl):
+                    fullUrl = state.md.normalizeLink(url)
+                    if not state.md.validateLink(fullUrl):
                         continue
 
                     urlText = links[ln].text
@@ -93,16 +92,16 @@ def linkify(state: StateCore) -> None:
                     # and remove it afterwards.
                     if not links[ln].schema:
                         urlText = HTTP_RE.sub(
-                            "", normalizeLinkText("http://" + urlText)
+                            "", state.md.normalizeLinkText("http://" + urlText)
                         )
                     elif links[ln].schema == "mailto:" and TEST_MAILTO_RE.search(
                         urlText
                     ):
                         urlText = MAILTO_RE.sub(
-                            "", normalizeLinkText("mailto:" + urlText)
+                            "", state.md.normalizeLinkText("mailto:" + urlText)
                         )
                     else:
-                        urlText = normalizeLinkText(urlText)
+                        urlText = state.md.normalizeLinkText(urlText)
 
                     pos = links[ln].index
 

markdown_it/rules_inline/autolink.py

@@ -1,7 +1,6 @@
 # Process autolinks '<protocol:...>'
 import re
 from .state_inline import StateInline
-from ..common.normalize_url import normalizeLinkText, normalizeLink, validateLink
 
 EMAIL_RE = re.compile(
     r"^<([a-zA-Z0-9.!#$%&\'*+\/=?^_`{|}~-]+@[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?(?:\.[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?)*)>"  # noqa: E501
@@ -25,8 +24,8 @@ def autolink(state: StateInline, silent: bool) -> bool:
     if linkMatch is not None:
 
         url = linkMatch.group(0)[1:-1]
-        fullUrl = normalizeLink(url)
-        if not validateLink(fullUrl):
+        fullUrl = state.md.normalizeLink(url)
+        if not state.md.validateLink(fullUrl):
             return False
 
         if not silent:
@@ -36,7 +35,7 @@ def autolink(state: StateInline, silent: bool) -> bool:
             token.info = "auto"
 
             token = state.push("text", "", 0)
-            token.content = normalizeLinkText(url)
+            token.content = state.md.normalizeLinkText(url)
 
             token = state.push("link_close", "a", -1)
             token.markup = "autolink"
@@ -49,8 +48,8 @@ def autolink(state: StateInline, silent: bool) -> bool:
     if emailMatch is not None:
 
         url = emailMatch.group(0)[1:-1]
-        fullUrl = normalizeLink("mailto:" + url)
-        if not validateLink(fullUrl):
+        fullUrl = state.md.normalizeLink("mailto:" + url)
+        if not state.md.validateLink(fullUrl):
             return False
 
         if not silent:
@@ -60,7 +59,7 @@ def autolink(state: StateInline, silent: bool) -> bool:
             token.info = "auto"
 
             token = state.push("text", "", 0)
-            token.content = normalizeLinkText(url)
+            token.content = state.md.normalizeLinkText(url)
 
             token = state.push("link_close", "a", -1)
             token.markup = "autolink"

markdown_it/rules_inline/image.py

@@ -5,7 +5,6 @@
 from .state_inline import StateInline
 from ..token import Token
 from ..common.utils import isSpace, normalizeReference
-from ..common.normalize_url import normalizeLink, validateLink
 
 
 def image(state: StateInline, silent: bool):
@@ -53,8 +52,8 @@ def image(state: StateInline, silent: bool):
         start = pos
         res = state.md.helpers.parseLinkDestination(state.src, pos, state.posMax)
         if res.ok:
-            href = normalizeLink(res.str)
-            if validateLink(href):
+            href = state.md.normalizeLink(res.str)
+            if state.md.validateLink(href):
                 pos = res.pos
             else:
                 href = ""

markdown_it/rules_inline/link.py

@@ -1,7 +1,6 @@
 # Process [link](<to> "stuff")
 
 from ..common.utils import normalizeReference, isSpace
-from ..common.normalize_url import normalizeLink, validateLink
 from .state_inline import StateInline
 
 
@@ -51,8 +50,8 @@ def link(state: StateInline, silent: bool):
         start = pos
         res = state.md.helpers.parseLinkDestination(state.src, pos, state.posMax)
         if res.ok:
-            href = normalizeLink(res.str)
-            if validateLink(href):
+            href = state.md.normalizeLink(res.str)
+            if state.md.validateLink(href):
                 pos = res.pos
             else:
                 href = ""