initial support for child extractor options

Using "parent-category>child-category" as extractor category in a config
file allows to set options for a child extractor when it was spawned by
that parent.

For example "reddit>gfycat" to set gfycat options for when it was found
in a reddit post.

{
    "extractor": {
        "gfycat": {
            "filename": "regular filename"
        },
        "reddit>gfycat": {
            "filename": "reddit-specific filename"
        }
    }
}

Note: This does currently not work for most imgur links due to how its
extractor hierarchy is structured.

gallery_dl/extractor/common.py

@@ -45,10 +45,6 @@ class Extractor():
  def __init__(self, match):
  self.log = logging.getLogger(self.category)
  self.url = match.string
-
- if self.basecategory:
- self.config = self._config_shared
- self.config_accumulate = self._config_shared_accumulate
  self._cfgpath = ("extractor", self.category, self.subcategory)
  self._parentdir = ""
 
@@ -98,16 +94,22 @@ def config_accumulate(self, key):
  return config.accumulate(self._cfgpath, key)
 
  def _config_shared(self, key, default=None):
- return config.interpolate_common(("extractor",), (
- (self.category, self.subcategory),
- (self.basecategory, self.subcategory),
- ), key, default)
+ return config.interpolate_common(
+ ("extractor",), self._cfgpath, key, default)
 
  def _config_shared_accumulate(self, key):
- values = config.accumulate(self._cfgpath, key)
- conf = config.get(("extractor",), self.basecategory)
- if conf:
- values[:0] = config.accumulate((self.subcategory,), key, conf=conf)
+ first = True
+ extr = ("extractor",)
+
+ for path in self._cfgpath:
+ if first:
+ first = False
+ values = config.accumulate(extr + path, key)
+ else:
+ conf = config.get(extr, path[0])
+ if conf:
+ values[:0] = config.accumulate(
+ (self.subcategory,), key, conf=conf)
  return values
 
  def request(self, url, method="GET", session=None,

gallery_dl/job.py

@@ -32,6 +32,21 @@ def __init__(self, extr, parent=None):
  self.kwdict = {}
  self.status = 0
 
+ cfgpath = []
+ if parent and parent.extractor.category != extr.category:
+ cat = "{}>{}".format(
+ parent.extractor.category, extr.category)
+ cfgpath.append((cat, extr.subcategory))
+ cfgpath.append((extr.category, extr.subcategory))
+ if extr.basecategory:
+ if not cfgpath:
+ cfgpath.append((extr.category, extr.subcategory))
+ cfgpath.append((extr.basecategory, extr.subcategory))
+ if cfgpath:
+ extr._cfgpath = cfgpath
+ extr.config = extr._config_shared
+ extr.config_accumulate = extr._config_shared_accumulate
+
  actions = extr.config("actions")
  if actions:
  from .actions import parse