bmk: add Bookmarks.__len__()

scanny · scanny · commit 3e0923429c39 · 2019-07-13T16:34:35.000-07:00
diff --git a/docx/bookmark.py b/docx/bookmark.py
@@ -6,9 +6,40 @@
     absolute_import, division, print_function, unicode_literals
 )
 
+from docx.shared import lazyproperty
+
 
 class Bookmarks(object):
     """Sequence of |Bookmark| objects."""
 
     def __init__(self, document_part):
         self._document_part = document_part
+
+    def __len__(self):
+        return len(self._finder.bookmark_pairs)
+
+    @lazyproperty
+    def _finder(self):
+        """_DocumentBookmarkFinder instance for this document."""
+        raise NotImplementedError
+
+
+class _DocumentBookmarkFinder(object):
+    """Provides access to bookmark oxml elements in an overall document."""
+
+    @property
+    def bookmark_pairs(self):
+        """List of (bookmarkStart, bookmarkEnd) element pairs for document.
+
+        The return value is a list of two-tuples (pairs) each containing
+        a start and its matching end element.
+
+        All story parts of the document are searched, including the main
+        document story, headers, footers, footnotes, and endnotes. The order
+        of part searching is not guaranteed, but bookmarks appear in document
+        order within a particular part. Only well-formed bookmarks appear.
+        Any open bookmarks (start but no end), reversed bookmarks (end before
+        start), or duplicate (name same as prior bookmark) bookmarks are
+        ignored.
+        """
+        raise NotImplementedError
diff --git a/tests/test_bookmark.py b/tests/test_bookmark.py
@@ -0,0 +1,36 @@
+# encoding: utf-8
+
+"""Test suite for the docx.bookmark module."""
+
+from __future__ import (
+    absolute_import, division, print_function, unicode_literals
+)
+
+import pytest
+
+from docx.bookmark import Bookmarks, _DocumentBookmarkFinder
+
+from .unitutil.mock import instance_mock, property_mock
+
+
+class DescribeBookmarks(object):
+
+    def it_knows_how_many_bookmarks_the_document_contains(
+            self, _finder_prop_, finder_):
+        _finder_prop_.return_value = finder_
+        finder_.bookmark_pairs = tuple((1, 2) for _ in range(42))
+        bookmarks = Bookmarks(None)
+
+        count = len(bookmarks)
+
+        assert count == 42
+
+    # fixture components ---------------------------------------------
+
+    @pytest.fixture
+    def finder_(self, request):
+        return instance_mock(request, _DocumentBookmarkFinder)
+
+    @pytest.fixture
+    def _finder_prop_(self, request):
+        return property_mock(request, Bookmarks, '_finder')
