[pp] add 'child' & 'child-after' events

gallery_dl/job.py

@@ -431,6 +431,12 @@ class DownloadJob(Job):
             return
         self.visited.add(url)
 
+        if "child" in self.hooks:
+            pathfmt = self.pathfmt
+            pathfmt.kwdict = kwdict
+            for callback in self.hooks["child"]:
+                callback(pathfmt)
+
         if cls := kwdict.get("_extractor"):
             extr = cls.from_url(url)
         else:
@@ -502,6 +508,12 @@ class DownloadJob(Job):
         else:
             self._write_unsupported(url)
 
+        if "child-after" in self.hooks:
+            pathfmt = self.pathfmt
+            pathfmt.kwdict = kwdict
+            for callback in self.hooks["child-after"]:
+                callback(pathfmt)
+
     def handle_finalize(self):
         if self.archive:
             if not self.status:

gallery_dl/option.py

@@ -179,7 +179,8 @@ class PrintAction(argparse.Action):
             event = event.strip().lower()
             if event not in {"init", "file", "after", "skip", "error",
                              "prepare", "prepare-after", "post", "post-after",
-                             "finalize", "finalize-success", "finalize-error"}:
+                             "finalize", "finalize-success", "finalize-error",
+                             "child", "child-after"}:
                 format_string = value
                 event = ("prepare",)