From cfc70a97ab960b2cd17f6e4ef3e76fb5b438ab0f Mon Sep 17 00:00:00 2001
From: Gio <sethg@ipi.org>
Date: Mon, 9 Dec 2019 00:56:27 -0600
Subject: [PATCH] Added an additional channel for downloading the metadata of
 an entire post or gallery.

---
 gallery_dl/extractor/message.py             |  1 +
 gallery_dl/extractor/patreon.py             |  4 ++++
 gallery_dl/job.py                           | 10 ++++++++
 gallery_dl/postprocessor/__init__.py        |  1 +
 gallery_dl/postprocessor/metadata_bypost.py | 26 +++++++++++++++++++++
 5 files changed, 42 insertions(+)
 create mode 100644 gallery_dl/postprocessor/metadata_bypost.py

diff --git a/gallery_dl/extractor/message.py b/gallery_dl/extractor/message.py
index 1831620a..088fdd67 100644
--- a/gallery_dl/extractor/message.py
+++ b/gallery_dl/extractor/message.py
@@ -52,3 +52,4 @@ class Message():
     #  Cookies = 5
     Queue = 6
     Urllist = 7
+    Metadata = 8
diff --git a/gallery_dl/extractor/patreon.py b/gallery_dl/extractor/patreon.py
index 9b13391f..60549983 100644
--- a/gallery_dl/extractor/patreon.py
+++ b/gallery_dl/extractor/patreon.py
@@ -69,6 +69,10 @@ class PatreonExtractor(Extractor):
                     post["type"] = "content"
                     yield Message.Url, url, text.nameext_from_url(url, post)
 
+            post.update({"metadata_only": True})
+            url = post.get("creator").get("image_url")
+            yield Message.Metadata, url, text.nameext_from_url(url, post)
+
     def posts(self):
         """Return all relevant post objects"""
 
diff --git a/gallery_dl/job.py b/gallery_dl/job.py
index 7a1f1955..3241c7c4 100644
--- a/gallery_dl/job.py
+++ b/gallery_dl/job.py
@@ -97,6 +97,12 @@ class Job():
                 self.update_kwdict(kwds)
                 self.handle_urllist(urls, kwds)
 
+        elif msg[0] == Message.Metadata:
+            _, url, kwds = msg
+            if self.pred_url(url, kwds):
+                self.update_kwdict(kwds)
+                self.handle_url(url, kwds)
+
         elif msg[0] == Message.Version:
             if msg[1] != 1:
                 raise "unsupported message-version ({}, {})".format(
@@ -188,6 +194,10 @@ class DownloadJob(Job):
             for pp in postprocessors:
                 pp.prepare(pathfmt)
 
+        if kwdict.get("metadata_only"):
+            self.handle_skip()
+            return
+
         if pathfmt.exists(archive):
             self.handle_skip()
             return
diff --git a/gallery_dl/postprocessor/__init__.py b/gallery_dl/postprocessor/__init__.py
index e63d4427..dbd87709 100644
--- a/gallery_dl/postprocessor/__init__.py
+++ b/gallery_dl/postprocessor/__init__.py
@@ -18,6 +18,7 @@ modules = [
     "mtime",
     "ugoira",
     "zip",
+    "metadata_bypost",
 ]
 
 log = logging.getLogger("postprocessor")
diff --git a/gallery_dl/postprocessor/metadata_bypost.py b/gallery_dl/postprocessor/metadata_bypost.py
new file mode 100644
index 00000000..35d4ef34
--- /dev/null
+++ b/gallery_dl/postprocessor/metadata_bypost.py
@@ -0,0 +1,26 @@
+# -*- coding: utf-8 -*-
+
+# Copyright 2019 Mike Fährmann
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License version 2 as
+# published by the Free Software Foundation.
+
+"""Write metadata to JSON files"""
+
+from .metadata import __postprocessor__ as MetadataPP
+
+
+class Metadata_BypostPP(MetadataPP):
+
+    def __init__(self, pathfmt, options):
+        MetadataPP.__init__(self, pathfmt, options)
+
+    def prepare(self, pathfmt):
+        if pathfmt.kwdict.get("metadata_only"):
+            MetadataPP.run(self, pathfmt)
+
+    def run(self, pathfmt):
+         return
+
+__postprocessor__ = Metadata_BypostPP