markdown: add hard breaks with \\

Plus some PEP8 enhancements

app/utils/filters/markdown.py

@@ -8,7 +8,8 @@ from bleach import clean
 from app.utils.bleach_allowlist import markdown_tags, markdown_attrs
 
 from app.utils.markdown_extensions.pclinks import PCLinkExtension
-from app.utils.markdown_extensions.escape_html import EscapeHtml
+from app.utils.markdown_extensions.hardbreaks import HardBreakExtension
+from app.utils.markdown_extensions.escape_html import EscapeHtmlExtension
 
 
 @app.template_filter('md')
@@ -25,8 +26,9 @@ def md(text):
         'sane_lists',
         'tables',
         CodeHiliteExtension(linenums=True, use_pygments=True),
-        EscapeHtml(),
+        EscapeHtmlExtension(),
         FootnoteExtension(UNIQUE_IDS=True),
+        HardBreakExtension(),
         TocExtension(baselevel=2),
         PCLinkExtension(),
     ]

app/utils/markdown_extensions/escape_html.py

@@ -1,7 +1,7 @@
 from markdown.extensions import Extension
 
 
-class EscapeHtml(Extension):
+class EscapeHtmlExtension(Extension):
     def extendMarkdown(self, md):
         md.preprocessors.deregister('html_block')
         md.inlinePatterns.deregister('html')

app/utils/markdown_extensions/hardbreaks.py

@@ -0,0 +1,9 @@
+from markdown.extensions import Extension
+from markdown.inlinepatterns import SubstituteTagPattern
+
+
+class HardBreakExtension(Extension):
+    def extendMarkdown(self, md):
+        BREAK_RE = r' *\\\\\n'
+        breakPattern = SubstituteTagPattern(BREAK_RE, 'br')
+        md.inlinePatterns.register(breakPattern, 'hardbreak', 185)

app/utils/markdown_extensions/pclinks.py

@@ -20,6 +20,7 @@ from app.models.poll import Poll
 from app.models.topic import Topic
 from app.models.user import Member
 
+
 class PCLinkExtension(Extension):
     def __init__(self, **kwargs):
         self.config = {
@@ -36,7 +37,7 @@ class PCLinkExtension(Extension):
         PCLINK_RE = r'\[\[([a-z]+): ?(\w+)\]\]'
         pclinkPattern = PCLinksInlineProcessor(PCLINK_RE, self.getConfigs())
         pclinkPattern.md = md
-        md.inlinePatterns.register(pclinkPattern, 'pclink', 75)
+        md.inlinePatterns.register(pclinkPattern, 'pclink', 135)
 
 
 class PCLinksInlineProcessor(InlineProcessor):