atom: switch from white-space: pre to converting newlines to <br>s

snarfed · snarfed · commit 0ac54362ae10 · 2019-09-04T13:09:53.000-07:00
...because some feed readers follow it too strictly and don't even line wrap, eg https://forum.newsblur.com/t/android-cant-read-line-pre-formatted-lines/6116 re: #80
diff --git a/README.md b/README.md
@@ -318,6 +318,8 @@ Changelog
   * Revise whitespace handling; use `white-space: pre` CSS in HTML output.
 * Facebook:
   * Bug fix: don't interpret `photo.php` as username in post URLs.
+* Atom:
+  * Switch from `white-space: pre` CSS back to converting newlines to `<br>`s because some feed readers ([eg NewsBlur](https://forum.newsblur.com/t/android-cant-read-line-pre-formatted-lines/6116)) follow it too strictly and don't even line wrap.
 * RSS:
   * Default title to ellipsized content.
 
diff --git a/granary/atom.py b/granary/atom.py
@@ -357,7 +357,11 @@ def _prepare_activity(a, reader=True):
 
   # Render content as HTML; escape &s
   obj['rendered_content'] = _encode_ampersands(microformats2.render_content(
-    primary, include_location=reader, render_attachments=True))
+    primary, include_location=reader, render_attachments=True,
+    # Readers often obey CSS white-space: pre strictly and don't even line wrap,
+    # so don't use it.
+    # https://forum.newsblur.com/t/android-cant-read-line-pre-formatted-lines/6116
+    white_space_pre=False))
 
   # Make sure every activity has the title field, since Atom <entry> requires
   # the title element.
diff --git a/granary/microformats2.py b/granary/microformats2.py
@@ -769,7 +769,7 @@ def hcard_to_html(hcard, parent_props=None):
 
 
 def render_content(obj, include_location=True, synthesize_content=True,
-                   render_attachments=False):
+                   render_attachments=False, white_space_pre=True):
   """Renders the content of an ActivityStreams object as HTML.
 
   Includes tags, mentions, and non-note/article attachments. (Note/article
@@ -784,6 +784,9 @@ def render_content(obj, include_location=True, synthesize_content=True,
     include_location: whether to render location, if provided
     synthesize_content: whether to generate synthetic content if the object
       doesn't have its own, e.g. 'likes this.' or 'shared this.'
+    white_space_pre: boolean, whether to wrap in CSS white-space: pre. If False,
+      newlines will be converted to <br> tags instead. Background:
+      https://indiewebcamp.com/note#Indieweb_whitespace_thinking
 
   Returns:
     string, rendered HTML
@@ -826,7 +829,10 @@ def render_content(obj, include_location=True, synthesize_content=True,
   # https://indiewebcamp.com/note#Indieweb_whitespace_thinking
   # https://github.com/snarfed/granary/issues/80
   if content and not obj.get('content_is_html') and '\n' in content:
-    content = '<div style="white-space: pre">%s</div>' % content
+    if white_space_pre:
+      content = '<div style="white-space: pre">%s</div>' % content
+    else:
+      content = content.replace('\n', '<br />\n')
 
   # linkify embedded links. ignore the "mention" tags that we added ourselves.
   # TODO: fix the bug in test_linkify_broken() in webutil/tests/test_util.py, then
diff --git a/granary/tests/test_microformats2.py b/granary/tests/test_microformats2.py
@@ -204,7 +204,7 @@ def test_render_content_multiple_image_attachments(self):
 <img class="u-photo" src="http://2" alt="" />
 </p>""", microformats2.render_content(obj, render_attachments=True))
 
-  def test_render_content_converts_newlines_to_brs(self):
+  def test_render_content_newlines_default_white_space_pre(self):
     self.assert_equals("""\
 <div style="white-space: pre">foo
 bar
@@ -214,6 +214,16 @@ def test_render_content_converts_newlines_to_brs(self):
   'tags': [{'url': 'http://baz', 'startIndex': 8, 'length': 3}]
 }))
 
+  def test_render_content_convert_newlines_to_brs(self):
+    self.assert_equals("""\
+foo<br />
+bar<br />
+<a href="http://baz">baz</a>
+""", microformats2.render_content({
+  'content': 'foo\nbar\nbaz',
+  'tags': [{'url': 'http://baz', 'startIndex': 8, 'length': 3}]
+}, white_space_pre=False))
+
   def test_render_content_omits_tags_without_urls(self):
     self.assert_equals("""\
 foo
@@ -633,8 +643,8 @@ def test_json_to_object_with_categories(self):
       },
     ], obj.get('tags'))
 
-  def test_json_to_object_converts_text_newlines_to_brs(self):
-    """Text newlines should be converted to <br>s."""
+  def test_json_to_object_text_newlines(self):
+    """Text newlines should not be converted to <br>s."""
     self.assert_equals({
       'objectType': 'note',
       'content': 'asdf\nqwer',
