[flickr] add 'metadata' option (#4227)

docs/configuration.rst

@@ -1541,6 +1541,27 @@ Description
     from `linking your Flickr account to gallery-dl <OAuth_>`__.
 
 
+extractor.flickr.metadata
+-------------------------
+Type
+    * ``bool``
+    * ``string``
+    * ``list`` of ``strings``
+Default
+    ``false``
+Example
+    * ``license,last_update,machine_tags``
+    * ``["license", "last_update", "machine_tags"]``
+Description
+    Extract additional metadata
+    (license, date_taken, original_format, last_update, geo, machine_tags, o_dims)
+
+    It is possible to specify a custom list of metadata includes.
+    See `the extras parameter <https://www.flickr.com/services/api/flickr.people.getPhotos.html>`__
+    in `Flickr API docs <https://www.flickr.com/services/api/>`__
+    for possible field names.
+
+
 extractor.flickr.videos
 -----------------------
 Type

gallery_dl/extractor/flickr.py

@@ -451,9 +451,19 @@ class FlickrAPI(oauth.OAuth1API):
         return data
 
     def _pagination(self, method, params, key="photos"):
-        params["extras"] = ("description,date_upload,tags,views,media,"
-                            "path_alias,owner_name,")
-        params["extras"] += ",".join("url_" + fmt[0] for fmt in self.formats)
+        extras = ("description,date_upload,tags,views,media,"
+                  "path_alias,owner_name,")
+        includes = self.extractor.config("metadata")
+        if includes:
+            if isinstance(includes, (list, tuple)):
+                includes = ",".join(includes)
+            elif not isinstance(includes, str):
+                includes = ("license,date_taken,original_format,last_update,"
+                            "geo,machine_tags,o_dims")
+            extras = extras + includes + ","
+        extras += ",".join("url_" + fmt[0] for fmt in self.formats)
+
+        params["extras"] = extras
         params["page"] = 1
 
         while True: