Feature metadata changed 621 (#684)

* Added metadata_changed to ExportResults, #621

* Updated docs

README.md

@@ -2981,6 +2981,9 @@ Returns a [ScoreInfo](#scoreinfo) data class object which provides access to the
 
 Returns list of PhotoInfo objects for *possible* duplicates or empty list if no matching duplicates.  Photos are considered possible duplicates if the photo's original file size, date created, height, and width match another those of another photo.  This does not do a byte-for-byte comparison or compute a hash which makes it fast and allows for identification of possible duplicates even if originals are not downloaded from iCloud.  The signature-based approach should be robust enough to match duplicates created either through the "duplicate photo" menu item or imported twice into the library but you should not rely on this 100% for identification of all duplicates.
 
+#### `hexdigest`
+Returns a unique digest of the photo's properties and metadata; useful for detecting changes in any property/metadata of the photo.
+
 #### `json()`
 
 Returns a JSON representation of all photo info.
@@ -4174,6 +4177,7 @@ Attributes:
 * exiftool_error: list of errors generated by exiftool during export
 * xattr_written: list of files with extended attributes written during export
 * xattr_skipped: list of files where extended attributes were skipped when update=True
+* metadata_changed: list of files where metadata changed since last export
 * deleted_files: reserved for use by osxphotos CLI
 * deleted_directories: reserved for use by osxphotos CLI
 * exported_album: reserved for use by osxphotos CLI

examples/post_function.py

@@ -50,6 +50,7 @@ def post_function(
     # exported_album: list of tuples of (filename, album_name) for exported files added to album with --add-exported-to-album
     # skipped_album: list of tuples of (filename, album_name) for skipped files added to album with --add-skipped-to-album
     # missing_album: list of tuples of (filename, album_name) for missing files added to album with --add-missing-to-album
+    # metadata_changed: list of filenames that had metadata changes since last export
 
     for filename in results.exported:
         # do your processing here

osxphotos/photoexporter.py

@@ -2,13 +2,11 @@
 """
 
 import dataclasses
-import hashlib
 import json
 import logging
 import os
 import pathlib
 import re
-import tempfile
 import typing as t
 from collections import namedtuple  # pylint: disable=syntax-error
 from dataclasses import asdict, dataclass
@@ -45,14 +43,13 @@ from .photokit import (
 from .phototemplate import RenderOptions
 from .rich_utils import add_rich_markup_tag
 from .uti import get_preferred_uti_extension
-from .utils import increment_filename, lineno, list_directory
+from .utils import hexdigest, increment_filename, lineno, list_directory
 
 __all__ = [
     "ExportError",
     "ExportOptions",
     "ExportResults",
     "PhotoExporter",
-    "hexdigest",
     "rename_jpeg_files",
 ]
 
@@ -266,6 +263,7 @@ class ExportResults:
         exported_album=None,
         skipped_album=None,
         missing_album=None,
+        metadata_changed=None,
     ):
         self.exported = exported or []
         self.new = new or []
@@ -292,6 +290,7 @@ class ExportResults:
         self.exported_album = exported_album or []
         self.skipped_album = skipped_album or []
         self.missing_album = missing_album or []
+        self.metadata_changed = metadata_changed or []
 
     def all_files(self):
         """return all filenames contained in results"""
@@ -342,6 +341,7 @@ class ExportResults:
         self.exported_album += other.exported_album
         self.skipped_album += other.skipped_album
         self.missing_album += other.missing_album
+        self.metadata_changed += other.metadata_changed
 
         return self
 
@@ -371,12 +371,14 @@ class ExportResults:
             + f",exported_album={self.exported_album}"
             + f",skipped_album={self.skipped_album}"
             + f",missing_album={self.missing_album}"
+            + f",metadata_changed={self.metadata_changed}"
             + ")"
         )
 
 
 class PhotoExporter:
     """Export a photo"""
+
     def __init__(self, photo: "PhotoInfo", tmpdir: t.Optional[str] = None):
         self.photo = photo
         self._render_options = RenderOptions()
@@ -739,7 +741,7 @@ class PhotoExporter:
             return ShouldUpdate.EDITED_SIG_DIFFERENT
 
         if options.force_update:
-            current_digest = hexdigest(self.photo.json())
+            current_digest = self.photo.hexdigest
             if current_digest != file_record.digest:
                 # metadata in Photos changed, force update
                 return ShouldUpdate.DIGEST_DIFFERENT
@@ -1179,8 +1181,9 @@ class PhotoExporter:
                 rec.dest_sig = fileutil.file_sig(dest)
             if options.exiftool:
                 rec.exifdata = self._exiftool_json_sidecar(options)
-            if options.force_update:
+            if self.photo.hexdigest != rec.digest:
-                rec.digest = hexdigest(photoinfo)
+                results.metadata_changed = [dest_str]
+            rec.digest = self.photo.hexdigest
 
         return results
 
@@ -2011,13 +2014,6 @@ class PhotoExporter:
         f.close()
 
 
-def hexdigest(strval):
-    """hexdigest of a string, using blake2b"""
-    h = hashlib.blake2b(digest_size=20)
-    h.update(bytes(strval, "utf-8"))
-    return h.hexdigest()
-
-
 def _check_export_suffix(src, dest, edited):
     """Helper function for exporting photos to check file extensions of destination path.
 

osxphotos/photoinfo.py

@@ -11,6 +11,7 @@ import os
 import os.path
 import pathlib
 from datetime import timedelta, timezone
+from functools import cached_property
 from typing import Optional
 
 import yaml
@@ -54,7 +55,7 @@ from .scoreinfo import ScoreInfo
 from .searchinfo import SearchInfo
 from .text_detection import detect_text
 from .uti import get_preferred_uti_extension, get_uti_for_extension
-from .utils import _get_resource_loc, list_directory
+from .utils import _get_resource_loc, hexdigest, list_directory
 
 __all__ = ["PhotoInfo", "PhotoInfoNone"]
 
@@ -1356,6 +1357,12 @@ class PhotoInfo:
             self._exiftool = exiftool
             return self._exiftool
 
+    @cached_property
+    def hexdigest(self):
+        """Returns a unique digest of the photo's properties and metadata;
+        useful for detecting changes in any property/metadata of the photo"""
+        return hexdigest(self.json())
+
     def detected_text(self, confidence_threshold=TEXT_DETECTION_CONFIDENCE_THRESHOLD):
         """Detects text in photo and returns lists of results as (detected text, confidence)
 

osxphotos/utils.py

@@ -3,6 +3,7 @@
 import datetime
 import fnmatch
 import glob
+import hashlib
 import importlib
 import inspect
 import logging
@@ -29,6 +30,7 @@ __all__ = [
     "expand_and_validate_filepath",
     "get_last_library_path",
     "get_system_library_path",
+    "hexdigest",
     "increment_filename_with_count",
     "increment_filename",
     "lineno",
@@ -517,3 +519,10 @@ def get_latest_version() -> Tuple[Optional[str], str]:
 def pluralize(count, singular, plural):
     """Return singular or plural based on count"""
     return singular if count == 1 else plural
+
+
+def hexdigest(strval: str) -> str:
+    """hexdigest of a string, using blake2b"""
+    h = hashlib.blake2b(digest_size=20)
+    h.update(bytes(strval, "utf-8"))
+    return h.hexdigest()