feat: Add crJson function on Reader (#279)

* fix: Binding for crJson

* Update c2pa.py

Author: tmathern

pyproject.toml

@@ -4,7 +4,7 @@ build-backend = "setuptools.build_meta"
 
 [project]
 name = "c2pa-python"
-version = "0.32.13"
+version = "0.32.14"
 requires-python = ">=3.10"
 description = "Python bindings for the C2PA Content Authenticity Initiative (CAI) library"
 readme = { file = "README.md", content-type = "text/markdown" }

src/c2pa/c2pa.py

@@ -48,6 +48,7 @@
     'c2pa_reader_from_manifest_data_and_stream',
     'c2pa_reader_json',
     'c2pa_reader_detailed_json',
+    'c2pa_reader_crjson',
     'c2pa_reader_resource_to_stream',
     'c2pa_reader_from_context',
     'c2pa_reader_with_stream',
@@ -561,6 +562,9 @@ def _setup_function(func, argtypes, restype=None):
 _setup_function(
     _lib.c2pa_reader_detailed_json, [
         ctypes.POINTER(C2paReader)], ctypes.c_void_p)
+_setup_function(
+    _lib.c2pa_reader_crjson, [
+        ctypes.POINTER(C2paReader)], ctypes.c_void_p)
 _setup_function(_lib.c2pa_reader_resource_to_stream, [ctypes.POINTER(
     C2paReader), ctypes.c_char_p, ctypes.POINTER(C2paStream)], ctypes.c_int64)
 _setup_function(
@@ -2631,6 +2635,27 @@ def detailed_json(self) -> str:
 
         return _convert_to_py_string(result)
 
+    def crjson(self) -> str:
+        """Get the manifest store as a crJSON string.
+
+        crJSON is a standardized JSON format for C2PA manifest data. This
+        call yields empty JSON ("{}") when there are no Content Credentials.
+
+        Returns:
+            The manifest store as a crJSON string.
+
+        Raises:
+            C2paError: If the Reader has been closed or the underlying C
+                      call returns null.
+        """
+
+        self._ensure_valid_state()
+
+        result = _lib.c2pa_reader_crjson(self._handle)
+        _check_ffi_operation_result(result, "Error parsing crJSON")
+
+        return _convert_to_py_string(result)
+
     def _get_manifest_field(self, extractor):
         """Extract a field from (cached) manifest data, or None if unavailable.
 

tests/test_unit_tests.py

@@ -271,6 +271,19 @@ def test_stream_read_detailed_and_parse(self):
             title = manifest_store["manifests"][manifest_store["active_manifest"]]["claim"]["dc:title"]
             self.assertEqual(title, DEFAULT_TEST_FILE_NAME)
 
+    def test_stream_read_crjson_and_parse(self):
+        with open(self.testPath, "rb") as file:
+            reader = Reader("image/jpeg", file)
+            crjson = reader.crjson()
+            self.assertTrue(crjson)
+            json.loads(crjson)
+
+    def test_stream_read_crjson_path_only(self):
+        with Reader(self.testPath) as reader:
+            crjson = reader.crjson()
+            self.assertTrue(crjson)
+            json.loads(crjson)
+
     def test_stream_read_string_stream_path_only(self):
         with Reader(self.testPath) as reader:
             json_data = reader.json()