Add reading and writing of embedded style maps

3 files changed, 57 insertions, 0 deletions

diff --git a/mammoth/docx/style_map.py b/mammoth/docx/style_map.py
new file mode 100644
index 0000000..2841830
--- /dev/null
+++ b/mammoth/docx/style_map.py
@@ -0,0 +1,17 @@
+from ..zips import open_zip
+
+
+_style_map_path = "mammoth/style-map"
+
+
+def write_style_map(fileobj, style_map):
+    with open_zip(fileobj, "a") as zip_file:
+        zip_file.write_str(_style_map_path, style_map)
+
+
+def read_style_map(fileobj):
+    with open_zip(fileobj, "r") as zip_file:
+        if zip_file.exists(_style_map_path):
+            return zip_file.read_str(_style_map_path)
+
+
diff --git a/mammoth/zips.py b/mammoth/zips.py
index c6fe358..24c6b1c 100644
--- a/mammoth/zips.py
+++ b/mammoth/zips.py
@@ -26,3 +26,9 @@ class _Zip(object):
             return True
         except KeyError:
             return False
+
+    def write_str(self, name, value):
+        self._zip_file.writestr(name, value)
+    
+    def read_str(self, name):
+        return self._zip_file.read(name).decode("utf8")
diff --git a/tests/docx/style_map_tests.py b/tests/docx/style_map_tests.py
new file mode 100644
index 0000000..f298e1d
--- /dev/null
+++ b/tests/docx/style_map_tests.py
@@ -0,0 +1,34 @@
+import io
+
+from nose.tools import istest, assert_equal
+
+from mammoth.docx.style_map import write_style_map, read_style_map
+from mammoth.zips import open_zip
+
+
+@istest
+def reading_embedded_style_map_on_document_without_embedded_style_map_returns_none():
+    fileobj = _normal_docx()
+    assert_equal(None, read_style_map(fileobj))
+
+
+@istest
+def embedded_style_map_can_be_read_after_being_written():
+    fileobj = _normal_docx()
+    write_style_map(fileobj, "p => h1")
+    assert_equal("p => h1", read_style_map(fileobj))
+
+
+@istest
+def embedded_style_map_is_written_to_separate_file():
+    fileobj = _normal_docx()
+    write_style_map(fileobj, "p => h1")
+    with open_zip(fileobj, "r") as zip_file:
+        assert_equal("p => h1", zip_file.read_str("mammoth/style-map"))
+
+
+def _normal_docx():
+    fileobj = io.BytesIO()
+    with open_zip(fileobj, "w") as zip_file:
+        zip_file.write_str("placeholder", "placeholder")
+    return fileobj