From 68371e6294bd0d0e0382d0a90bc2ae4ed85f6f1b Mon Sep 17 00:00:00 2001
From: Kovid Goyal <kovid@kovidgoyal.net>
Date: Sun, 27 Mar 2016 11:32:20 +0530
Subject: [PATCH] Compactify the JSON repr of HTML a bit

---
 src/calibre/srv/render_book.py | 21 ++++++++++++++-------
 1 file changed, 14 insertions(+), 7 deletions(-)

diff --git a/src/calibre/srv/render_book.py b/src/calibre/srv/render_book.py
index 6db12fc588..29178e2e05 100644
--- a/src/calibre/srv/render_book.py
+++ b/src/calibre/srv/render_book.py
@@ -177,26 +177,33 @@ def split_name(name):
         return l[1:], r
     return None, l
 
+boolean_attributes = frozenset('allowfullscreen,async,autofocus,autoplay,checked,compact,controls,declare,default,defaultchecked,defaultmuted,defaultselected,defer,disabled,enabled,formnovalidate,hidden,indeterminate,inert,ismap,itemscope,loop,multiple,muted,nohref,noresize,noshade,novalidate,nowrap,open,pauseonexit,readonly,required,reversed,scoped,seamless,selected,sortable,truespeed,typemustmatch,visible'.split(','))  # noqa
+
 def serialize_elem(elem, nsmap):
     ns, name = split_name(elem.tag)
-    attribs = []
     ans = {'n':name}
     if elem.text:
-        ans['te'] = elem.text
+        ans['x'] = elem.text
     if elem.tail:
-        ans['ta'] = elem.tail
+        ans['l'] = elem.tail
     if ns:
         ns = nsmap[ns]
         if ns:
-            ans['ns'] = ns
+            ans['s'] = ns
+    attribs = []
     for attr, val in elem.items():
         attr_ns, aname = split_name(attr)
-        s = {'n':aname, 'v':val}
+        al = attr.lower()
+        if not attr_ns and al in boolean_attributes:
+            if val and val.lower() in (al, ''):
+                attribs.append([al, al])
+            continue
+        attrib = [attr, val]
         if attr_ns:
             attr_ns = nsmap[attr_ns]
             if attr_ns:
-                s['ns'] = attr_ns
-        attribs.append(s)
+                attrib.append(attr_ns)
+        attribs.append(attrib)
     if attribs:
         ans['a'] = attribs
     return ans