Custom column metadata for PDF

src/calibre/ebooks/metadata/xmp.py

@@ -6,14 +6,14 @@ from __future__ import (unicode_literals, division, absolute_import,
 __license__ = 'GPL v3'
 __copyright__ = '2014, Kovid Goyal <kovid at kovidgoyal.net>'
 
-import re, sys
+import re, sys, copy, json
 from itertools import repeat
 from collections import defaultdict
 
 from lxml import etree
 from lxml.builder import ElementMaker
 
-from calibre import replace_entities
+from calibre import prints
 from calibre.ebooks.metadata import check_isbn, check_doi
 from calibre.ebooks.metadata.book.base import Metadata
 from calibre.utils.date import parse_date, isoformat, now
@@ -39,6 +39,7 @@ NS_MAP = {
     'x': 'adobe:ns:meta/',
     'calibre': 'http://calibre-ebook.com/xmp-namespace',
     'calibreSI': 'http://calibre-ebook.com/xmp-namespace-series-index',
+    'calibreCC': 'http://calibre-ebook.com/xmp-namespace-custom-columns',
 }
 KNOWN_ID_SCHEMES = {'isbn', 'url', 'doi'}
 
@@ -80,8 +81,8 @@ def serialize_xmp_packet(root, encoding='utf-8'):
 def read_simple_property(elem):
     # A simple property
     if elem.text:
-        return replace_entities(elem.text)
+        return elem.text
-    return replace_entities(elem.get(expand('rdf:resource'), ''))
+    return elem.get(expand('rdf:resource'), '')
 
 def read_lang_alt(parent):
     # A text value with possible alternate values in different languages
@@ -153,6 +154,28 @@ def read_series(root):
                 return series, series_index
     return None, None
 
+def read_user_metadata(mi, root):
+    from calibre.utils.config import from_json
+    from calibre.ebooks.metadata.book.json_codec import decode_is_multiple
+    fields = set()
+    for item in XPath('//calibre:custom_metadata')(root):
+        for li in XPath('./rdf:Bag/rdf:li')(item):
+            name = XPath('descendant::calibreCC:name')(li)
+            if name:
+                name = name[0].text
+                if name.startswith('#') and name not in fields:
+                    val = XPath('descendant::rdf:value')(li)
+                    if val:
+                        fm = val[0].text
+                        try:
+                            fm = json.loads(fm, object_hook=from_json)
+                            decode_is_multiple(fm)
+                            mi.set_user_metadata(name, fm)
+                            fields.add(name)
+                        except:
+                            prints('Failed to read user metadata:', name)
+                            import traceback
+                            traceback.print_exc()
 
 def read_xmp_identifers(parent):
     ''' For example:
@@ -254,6 +277,8 @@ def metadata_from_xmp_packet(raw_bytes):
     if identifiers:
         mi.set_identifiers(identifiers)
 
+    read_user_metadata(mi, root)
+
     return mi
 
 def consolidate_metadata(info_mi, xmp_packet):
@@ -326,6 +351,35 @@ def create_series(calibre, series, series_index):
     si.text = '%.2f' % series_index
     s.append(si)
 
+def create_user_metadata(calibre, all_user_metadata):
+    from calibre.utils.config import to_json
+    from calibre.ebooks.metadata.book.json_codec import object_to_unicode, encode_is_multiple
+
+    s = calibre.makeelement(expand('calibre:custom_metadata'))
+    calibre.append(s)
+    bag = s.makeelement(expand('rdf:Bag'))
+    s.append(bag)
+    for name, fm in all_user_metadata.iteritems():
+        try:
+            fm = copy.copy(fm)
+            encode_is_multiple(fm)
+            fm = object_to_unicode(fm)
+            fm = json.dumps(fm, default=to_json, ensure_ascii=False)
+        except:
+            prints('Failed to write user metadata:', name)
+            import traceback
+            traceback.print_exc()
+            continue
+        li = bag.makeelement(expand('rdf:li'))
+        li.set(expand('rdf:parseType'), 'Resource')
+        bag.append(li)
+        n = li.makeelement(expand('calibreCC:name'))
+        li.append(n)
+        n.text = name
+        val = li.makeelement(expand('rdf:value'))
+        val.text = fm
+        li.append(val)
+
 def metadata_to_xmp_packet(mi):
     A = ElementMaker(namespace=NS_MAP['x'], nsmap=nsmap('x'))
     R = ElementMaker(namespace=NS_MAP['rdf'], nsmap=nsmap('rdf'))
@@ -374,7 +428,7 @@ def metadata_to_xmp_packet(mi):
     d.text = isoformat(now(), as_utc=False)
     xmp.append(d)
 
-    calibre = rdf.makeelement(expand('rdf:Description'), nsmap=nsmap('calibre', 'calibreSI'))
+    calibre = rdf.makeelement(expand('rdf:Description'), nsmap=nsmap('calibre', 'calibreSI', 'calibreCC'))
     calibre.set(expand('rdf:about'), '')
     rdf.append(calibre)
     if not mi.is_null('rating'):
@@ -389,6 +443,10 @@ def metadata_to_xmp_packet(mi):
     for x in ('title_sort', 'author_sort'):
         if not mi.is_null(x):
             create_simple_property(calibre, 'calibre:'+x, getattr(mi, x))
+
+    all_user_metadata = mi.get_all_user_metadata(True)
+    if all_user_metadata:
+        create_user_metadata(calibre, all_user_metadata)
     return serialize_xmp_packet(root)
 
 def find_used_namespaces(elem):