Serialization of parsed fonts

src/tinycss/fonts3.py

@@ -64,6 +64,24 @@ LEGACY_FONT_SPEC = frozenset('caption icon menu message-box small-caption status
 GENERIC_FAMILIES = frozenset('serif sans-serif sansserif cursive fantasy monospace'.split())
 SIMPLE_NAME_PAT = re.compile(r'[a-zA-Z][a-zA-Z0-9_-]*$')
 
+def serialize_font(font_dict):
+    ans = []
+    for x in 'style variant weight stretch'.split():
+        val = font_dict.get('font-' + x)
+        if val is not None:
+            ans.append(val)
+    val = font_dict.get('font-size')
+    if val is not None:
+        fs = val
+        val = font_dict.get('line-height')
+        if val is not None:
+            fs += '/' + val
+        ans.append(fs)
+    val = font_dict.get('font-family')
+    if val:
+        ans.append(serialize_font_family(val))
+    return ' '.join(ans)
+
 def parse_font(css_string):
     # See https://www.w3.org/TR/css-fonts-3/#font-prop
     style = variant = weight = stretch = size = height = None

src/tinycss/tests/fonts3.py

@@ -6,7 +6,7 @@ from __future__ import (unicode_literals, division, absolute_import,
 __license__ = 'GPL v3'
 __copyright__ = '2014, Kovid Goyal <kovid at kovidgoyal.net>'
 
-from tinycss.fonts3 import CSSFonts3Parser, parse_font_family, parse_font
+from tinycss.fonts3 import CSSFonts3Parser, parse_font_family, parse_font, serialize_font
 from tinycss.tests import BaseTest
 
 class TestFonts3(BaseTest):
@@ -52,6 +52,7 @@ class TestFonts3(BaseTest):
         def t(raw, **kw):
             q = {('line' if k == 'height' else 'font') + '-' + k:v for k, v in kw.iteritems()}
             self.ae(q, parse_font(raw))
+            self.ae(q, parse_font(serialize_font(q)))
         t('caption', family=['sans-serif'])
         t('serif', family=['serif'])
         t('12pt/14pt sans-serif', size='12pt', height='14pt', family=['sans-serif'])