implement ability to load external extractor classes

- -X/--extractors
- extractor.module-sources

docs/options.md

@@ -8,10 +8,11 @@
     --version                   Print program version and exit
     -i, --input-file FILE       Download URLs found in FILE ('-' for stdin).
                                 More than one --input-file can be specified
-    -d, --destination PATH      Target location for file downloads
-    -D, --directory PATH        Exact location for file downloads
     -f, --filename FORMAT       Filename format string for downloaded files
                                 ('/O' for "original" filenames)
+    -d, --destination PATH      Target location for file downloads
+    -D, --directory PATH        Exact location for file downloads
+    -X, --extractors PATH       Load external extractors from PATH
     --proxy URL                 Use the specified proxy
     --source-address IP         Client-side IP address to bind to
     --user-agent UA             User-Agent request header

gallery_dl/__init__.py

@@ -11,7 +11,7 @@ import logging
 from . import version, config, option, output, extractor, job, util, exception
 
 __author__ = "Mike Fährmann"
-__copyright__ = "Copyright 2014-2022 Mike Fährmann"
+__copyright__ = "Copyright 2014-2023 Mike Fährmann"
 __license__ = "GPLv2"
 __maintainer__ = "Mike Fährmann"
 __email__ = "mike_faehrmann@web.de"
@@ -105,14 +105,6 @@ def main():
 
             output.ANSI = True
 
-        # extractor modules
-        modules = config.get(("extractor",), "modules")
-        if modules is not None:
-            if isinstance(modules, str):
-                modules = modules.split(",")
-            extractor.modules = modules
-            extractor._module_iter = iter(modules)
-
         # format string separator
         separator = config.get((), "format-separator")
         if separator:
@@ -147,6 +139,44 @@ def main():
 
             log.debug("Configuration Files %s", config._files)
 
+        # extractor modules
+        modules = config.get(("extractor",), "modules")
+        if modules is not None:
+            if isinstance(modules, str):
+                modules = modules.split(",")
+            extractor.modules = modules
+
+        # external modules
+        if args.extractor_sources:
+            sources = args.extractor_sources
+            sources.append(None)
+        else:
+            sources = config.get(("extractor",), "module-sources")
+
+        if sources:
+            import os
+            modules = []
+
+            for source in sources:
+                if source:
+                    path = util.expand_path(source)
+                    try:
+                        files = os.listdir(path)
+                        modules.append(extractor._modules_path(path, files))
+                    except Exception as exc:
+                        log.warning("Unable to load modules from %s (%s: %s)",
+                                    path, exc.__class__.__name__, exc)
+                else:
+                    modules.append(extractor._modules_internal())
+
+            if len(modules) > 1:
+                import itertools
+                extractor._module_iter = itertools.chain(*modules)
+            elif not modules:
+                extractor._module_iter = ()
+            else:
+                extractor._module_iter = iter(modules[0])
+
         if args.list_modules:
             extractor.modules.append("")
             sys.stdout.write("\n".join(extractor.modules))

gallery_dl/extractor/__init__.py

@@ -1,11 +1,12 @@
 # -*- coding: utf-8 -*-
 
-# Copyright 2015-2022 Mike Fährmann
+# Copyright 2015-2023 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.
 
+import sys
 import re
 
 modules = [
@@ -217,20 +218,33 @@ def extractors():
 # --------------------------------------------------------------------
 # internals
 
-_cache = []
-_module_iter = iter(modules)
-
 
 def _list_classes():
-    """Yield all available extractor classes"""
+    """Yield available extractor classes"""
     yield from _cache
 
-    globals_ = globals()
-    for module_name in _module_iter:
-        module = __import__(module_name, globals_, None, (), 1)
+    for module in _module_iter:
         yield from add_module(module)
 
-    globals_["_list_classes"] = lambda : _cache
+    globals()["_list_classes"] = lambda : _cache
+
+
+def _modules_internal():
+    globals_ = globals()
+    for module_name in modules:
+        yield __import__(module_name, globals_, None, (), 1)
+
+
+def _modules_path(path, files):
+    sys.path.insert(0, path)
+    try:
+        return [
+            __import__(name[:-3])
+            for name in files
+            if name.endswith(".py")
+        ]
+    finally:
+        del sys.path[0]
 
 
 def _get_classes(module):
@@ -240,3 +254,7 @@ def _get_classes(module):
             hasattr(cls, "pattern") and cls.__module__ == module.__name__
         )
     ]
+
+
+_cache = []
+_module_iter = _modules_internal()

gallery_dl/option.py

@@ -110,6 +110,12 @@ def build_parser():
         help=("Download URLs found in FILE ('-' for stdin). "
               "More than one --input-file can be specified"),
     )
+    general.add_argument(
+        "-f", "--filename",
+        dest="filename", metavar="FORMAT",
+        help=("Filename format string for downloaded files "
+              "('/O' for \"original\" filenames)"),
+    )
     general.add_argument(
         "-d", "--destination",
         dest="base-directory", metavar="PATH", action=ConfigAction,
@@ -121,10 +127,9 @@ def build_parser():
         help="Exact location for file downloads",
     )
     general.add_argument(
-        "-f", "--filename",
-        dest="filename", metavar="FORMAT",
-        help=("Filename format string for downloaded files "
-              "('/O' for \"original\" filenames)"),
+        "-X", "--extractors",
+        dest="extractor_sources", metavar="PATH", action="append",
+        help="Load external extractors from PATH",
     )
     general.add_argument(
         "--proxy",

gallery_dl/version.py

@@ -6,4 +6,4 @@
 # it under the terms of the GNU General Public License version 2 as
 # published by the Free Software Foundation.
 
-__version__ = "1.24.5"
+__version__ = "1.25.0-dev"

test/test_extractor.py

@@ -46,7 +46,7 @@ class TestExtractorModule(unittest.TestCase):
 
     def setUp(self):
         extractor._cache.clear()
-        extractor._module_iter = iter(extractor.modules)
+        extractor._module_iter = extractor._modules_internal()
         extractor._list_classes = _list_classes
 
     def test_find(self):