[pp:metadata] add 'metadata-path' option (#6582)

https://github.com/mikf/gallery-dl/issues/6582#issuecomment-2781643835

docs/configuration.rst

@@ -6611,6 +6611,17 @@ Description
     Note: `metadata.extension`_ is ignored if this option is set.
 
 
+metadata.metadata-path
+----------------------
+Type
+    ``string``
+Example
+    ``"_meta_path"``
+Description
+    Insert the path of generated files
+    into metadata dictionaries as the given name.
+
+
 metadata.event
 --------------
 Type

gallery_dl/postprocessor/metadata.py

@@ -108,6 +108,7 @@ class MetadataPP(PostProcessor):
         self.omode = options.get("open", omode)
         self.encoding = options.get("encoding", "utf-8")
         self.skip = options.get("skip", False)
+        self.meta_path = options.get("metadata-path")
 
     def run(self, pathfmt):
         archive = self.archive
@@ -120,6 +121,9 @@ class MetadataPP(PostProcessor):
             directory = self._directory(pathfmt)
         path = directory + self._filename(pathfmt)
 
+        if self.meta_path is not None:
+            pathfmt.kwdict[self.meta_path] = path
+
         if self.skip and os.path.exists(path):
             return
 

test/test_postprocessor.py

@@ -555,6 +555,16 @@ class MetadataTest(BasePostprocessorTest):
         path = self.pathfmt.realdirectory + "test_file__meta_.data"
         m.assert_called_once_with(path, "w", encoding="utf-8")
 
+    def test_metadata_meta_path(self):
+        self._create({
+            "metadata-path": "_meta_path",
+        })
+
+        self._trigger()
+
+        self.assertEqual(self.pathfmt.kwdict["_meta_path"],
+                         self.pathfmt.realpath + ".json")
+
     def test_metadata_stdout(self):
         self._create({"filename": "-", "indent": None, "sort": True})