[arena] add 'channel' extractor (#5847 #8509)

* feat: issue 5847 site support for are.na
* flake8 lint error fix
* class name error fix
* update
    - prevent unnecessary request to 'page_url'
    - fix pagination
    - simplify block extraction code
    TODO: - rewrite without GalleryExtractor
          - extractors for Blocks, Users, etc
* supportedsites
* tests
* rename to 'channel' extractor
* update site title to 'Are.na'
* prioritize attachments

---------

Co-authored-by: Mike Fährmann <mike_faehrmann@web.de>

docs/supportedsites.md

@@ -109,6 +109,12 @@ Consider all listed sites to potentially be NSFW.
     <td>Search Results, Series, Subscriptions, Tag Searches, User Profiles, User Bookmarks, User Series, User Works, Works</td>
     <td>Supported</td>
 </tr>
+<tr id="arena" title="arena">
+    <td>Are.na</td>
+    <td>https://are.na/</td>
+    <td>Channels</td>
+    <td></td>
+</tr>
 <tr id="artstation" title="artstation">
     <td>ArtStation</td>
     <td>https://www.artstation.com/</td>

gallery_dl/extractor/__init__.py

@@ -26,6 +26,7 @@ modules = [
     "ao3",
     "arcalive",
     "architizer",
+    "arena",
     "artstation",
     "aryion",
     "batoto",

gallery_dl/extractor/arena.py

@@ -0,0 +1,85 @@
+# -*- coding: utf-8 -*-
+
+# Copyright 2025 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.
+
+"""Extractor for https://are.na/"""
+
+from .common import GalleryExtractor
+
+
+class ArenaChannelExtractor(GalleryExtractor):
+    """Extractor for are.na channels"""
+    category = "arena"
+    subcategory = "channel"
+    root = "https://are.na"
+    pattern = r"(?:https?://)?(?:www\.)?are\.na/[^/?#]+/([^/?#]+)"
+    example = "https://are.na/evan-collins-1522646491/cassette-futurism"
+
+    def metadata(self, page):
+        info = self.request_json(
+            f"https://api.are.na/v2/channels/{self.groups[0]}")
+
+        return {
+            "gallery_id"  : info.get("slug") or str(info.get("id")),
+            "channel_id"  : info.get("id"),
+            "channel_slug": info.get("slug"),
+            "title"       : info.get("title") or "",
+            "count"       : info.get("length") or 0,
+            "user"        : info.get("user"),
+            "date"        : self.parse_datetime_iso(info.get("created_at")),
+            "date_updated": self.parse_datetime_iso(info.get("updated_at")),
+        }
+
+    def images(self, page):
+        api = f"https://api.are.na/v2/channels/{self.groups[0]}/contents"
+        limit = 100
+        params = {"page": 1, "per": limit}
+
+        while True:
+            data = self.request_json(api, params=params)
+
+            contents = data.get("contents")
+            if not contents:
+                return
+
+            for block in contents:
+                url = None
+                meta = {
+                    "id": block.get("id"),
+                    "block_class": block.get("class"),
+                    "block_title": block.get("title") or block.get(
+                        "generated_title") or "",
+                }
+
+                # Attachments (e.g., PDFs, files)
+                if attachment := block.get("attachment"):
+                    url = attachment.get("url")
+
+                # Images
+                elif image := block.get("image"):
+                    # Prefer original image
+                    if original := image.get("original"):
+                        url = original.get("url")
+                    # Fallback to display/large image if present
+                    elif display := image.get("display"):
+                        url = display.get("url")
+                    elif large := image.get("large"):
+                        url = large.get("url")
+
+                # Some Links/Channels may not have downloadable media
+                if not url:
+                    continue
+
+                # Provide source link if it exists
+                if src := block.get("source"):
+                    meta["source_url"] = src.get("url") or ""
+
+                yield url, meta
+
+            if len(contents) < limit:
+                return
+            params["page"] += 1

scripts/supportedsites.py

@@ -30,6 +30,7 @@ CATEGORY_MAP = {
     "ao3"            : "Archive of Our Own",
     "archivedmoe"    : "Archived.Moe",
     "archiveofsins"  : "Archive of Sins",
+    "arena"          : "Are.na",
     "artstation"     : "ArtStation",
     "aryion"         : "Eka's Portal",
     "atfbooru"       : "ATFBooru",

test/results/arena.py

@@ -0,0 +1,166 @@
+# -*- coding: utf-8 -*-
+
+# 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.
+
+from gallery_dl.extractor import arena
+
+
+__tests__ = (
+{
+    "#url"     : "https://are.na/evan-collins-1522646491/cassette-futurism",
+    "#class"   : arena.ArenaChannelExtractor,
+    "#pattern" : r"https://d2w9rnfcy7mm78\.cloudfront\.net/\d+/original_\w+\.\w+\?\d+\?bc=\d",
+    "#count"   : 160,
+
+    "block_class" : "Image",
+    "block_title" : str,
+    "channel_id"  : 1102343,
+    "channel_slug": "cassette-futurism",
+    "count"       : 160,
+    "date"        : "dt:2021-05-31 20:38:28",
+    "date_updated": "dt:2025-10-24 15:25:40",
+    "gallery_id"  : "cassette-futurism",
+    "id"          : int,
+    "num"         : range(1, 160),
+    "title"       : "Cassette Futurism",
+    "user"        : {
+        "avatar"         : "https://static.avatars.are.na/51156/small_8c6098f64217eca6b4bcff44a7abf2d7.jpg?1563035757",
+        "badge"          : "premium",
+        "base_class"     : "User",
+        "can_index"      : True,
+        "channel_count"  : range(250, 300),
+        "class"          : "User",
+        "created_at"     : "2018-04-02T05:21:30.282Z",
+        "first_name"     : "Evan",
+        "follower_count" : range(4900, 6000),
+        "following_count": range(10, 20),
+        "full_name"      : "Evan Collins",
+        "id"             : 51156,
+        "initials"       : "EC",
+        "is_confirmed"   : True,
+        "is_exceeding_connections_limit": False,
+        "is_lifetime_premium": False,
+        "is_pending_confirmation": False,
+        "is_pending_reconfirmation": False,
+        "is_premium"     : True,
+        "is_supporter"   : False,
+        "last_name"      : "Collins",
+        "metadata"       : {"description": None},
+        "profile_id"     : 171860,
+        "slug"           : "evan-collins-1522646491",
+        "username"       : "Evan Collins",
+        "avatar_image"   : {
+            "display": "https://static.avatars.are.na/51156/medium_8c6098f64217eca6b4bcff44a7abf2d7.jpg?1563035757",
+            "thumb"  : "https://static.avatars.are.na/51156/small_8c6098f64217eca6b4bcff44a7abf2d7.jpg?1563035757",
+        },
+    },
+},
+
+{
+    "#url"     : "https://are.na/lachie/transparent-tech-cobxde9pu40",
+    "#class"   : arena.ArenaChannelExtractor,
+    "#pattern" : r"https://d2w9rnfcy7mm78\.cloudfront\.net/\d+/original_\w+(\.\w+)?\?\d+\?bc=\d",
+    "#count"   : 89,
+
+    "block_class" : str,
+    "block_title" : str,
+    "channel_id"  : 2599871,
+    "channel_slug": "transparent-tech-cobxde9pu40",
+    "count"       : 91,
+    "date"        : "dt:2024-01-14 02:37:22",
+    "date_updated": "dt:2025-10-20 20:52:09",
+    "gallery_id"  : "transparent-tech-cobxde9pu40",
+    "id"          : int,
+    "num"         : int,
+    "?source_url" : str,
+    "title"       : "🫙 Transparent Tech",
+    "user"        : {
+        "avatar"         : "https://static.avatars.are.na/55241/small_fdcab74d56d0d9b93930333bdea50f4a.jpg?1738898629",
+        "badge"          : "premium",
+        "base_class"     : "User",
+        "can_index"      : True,
+        "channel_count"  : 219,
+        "class"          : "User",
+        "created_at"     : "2018-05-03T07:13:39.847Z",
+        "first_name"     : "lachie",
+        "follower_count" : range(80, 120),
+        "following_count": range(40, 80),
+        "full_name"      : "lachie 🔐",
+        "id"             : 55241,
+        "initials"       : "l🔐",
+        "is_confirmed"   : True,
+        "is_exceeding_connections_limit": False,
+        "is_lifetime_premium": False,
+        "is_pending_confirmation": False,
+        "is_pending_reconfirmation": False,
+        "is_premium"     : True,
+        "is_supporter"   : False,
+        "last_name"      : "🔐",
+        "metadata"       : {"description": None},
+        "profile_id"     : 188402,
+        "slug"           : "lachie",
+        "username"       : "lachie 🔐",
+        "avatar_image"   : {
+            "display": "https://static.avatars.are.na/55241/medium_fdcab74d56d0d9b93930333bdea50f4a.jpg?1738898629",
+            "thumb"  : "https://static.avatars.are.na/55241/small_fdcab74d56d0d9b93930333bdea50f4a.jpg?1738898629",
+        },
+    },
+},
+
+{
+    "#url"     : "https://www.are.na/mikf/touhou-zr5p8idnkag",
+    "#class"   : arena.ArenaChannelExtractor,
+    "#results" : (
+        "https://d2w9rnfcy7mm78.cloudfront.net/40871580/original_3fb729c818f92de4539d4ff263eb6056.png?1762357121?bc=0",
+        "https://d2w9rnfcy7mm78.cloudfront.net/40871591/original_91d7c8144a5ba9776118f0af6d923f94.png?1762357155?bc=0",
+        "https://d2w9rnfcy7mm78.cloudfront.net/40871607/original_766f89eb3b06cc84372bea9d58132c93.png?1762357207?bc=0",
+        "https://attachments.are.na/40873309/ebf4eae61a70773f7494e10a98b18fe3.mp4?1762359389",
+        "https://d2w9rnfcy7mm78.cloudfront.net/40873379/original_289824f61eade100785db100652abd9a.jpg?1762359483?bc=0",
+    ),
+
+    "block_class" : str,
+    "block_title" : str,
+    "channel_id"  : 4422732,
+    "channel_slug": "touhou-zr5p8idnkag",
+    "count"       : 6,
+    "date"        : "dt:2025-11-05 15:37:40",
+    "date_updated": "dt:2025-11-10 19:52:52",
+    "gallery_id"  : "touhou-zr5p8idnkag",
+    "id"          : int,
+    "title"       : '''Touhou "東方"''',
+    "user"        : {
+        "avatar"         : "",
+        "badge"          : None,
+        "base_class"     : "User",
+        "can_index"      : False,
+        "channel_count"  : 3,
+        "class"          : "User",
+        "created_at"     : "2025-11-05T15:35:15.242Z",
+        "first_name"     : "mikf",
+        "follower_count" : 0,
+        "following_count": 0,
+        "full_name"      : "mikf .",
+        "id"             : 1127493,
+        "initials"       : "m.",
+        "is_confirmed"   : True,
+        "is_exceeding_connections_limit": False,
+        "is_lifetime_premium": False,
+        "is_pending_confirmation": False,
+        "is_pending_reconfirmation": False,
+        "is_premium"     : False,
+        "is_supporter"   : False,
+        "last_name"      : ".",
+        "metadata"       : {"description": None},
+        "profile_id"     : 4422723,
+        "slug"           : "mikf",
+        "username"       : "mikf .",
+        "avatar_image"   : {
+            "display": "",
+            "thumb"  : "",
+        },
+    },
+},
+
+)