support 'metadata-*' names for '*-metadata' options

For example, instead of 'url-metadata' it is now also possible to use
'metadata-url' as option name.

- metadata-url
- metadata-path
- metadata-http
- metadata-version
- metadata-parent

docs/configuration.rst

@@ -166,6 +166,8 @@ Description
 
 extractor.*.parent-metadata
 ---------------------------
+extractor.*.metadata-parent
+---------------------------
 Type
     * ``bool``
     * ``string``
@@ -642,12 +644,12 @@ Description
     `format strings`_.
 
 
+extractor.*.metadata-url
+------------------------
 extractor.*.url-metadata
 ------------------------
 Type
     ``string``
-Default
-    ``null``
 Description
     Insert a file's download URL into its metadata dictionary as the given name.
 
@@ -658,12 +660,12 @@ Description
     with a ``metadata`` post processor, etc.
 
 
+extractor.*.metadata-path
+-------------------------
 extractor.*.path-metadata
 -------------------------
 Type
     ``string``
-Default
-    ``null``
 Description
     Insert a reference to the current
     `PathFormat <https://github.com/mikf/gallery-dl/blob/v1.24.2/gallery_dl/path.py#L27>`__
@@ -673,12 +675,12 @@ Description
     to access the current file's filename as ``"{gdl_path.filename}"``.
 
 
+extractor.*.metadata-http
+-------------------------
 extractor.*.http-metadata
 -------------------------
 Type
     ``string``
-Default
-    ``null``
 Description
     Insert an ``object`` containing a file's HTTP headers and
     ``filename``, ``extension``, and ``date`` parsed from them
@@ -689,12 +691,12 @@ Description
     and its parsed form as ``"{gdl_http[date]}"``.
 
 
+extractor.*.metadata-version
+----------------------------
 extractor.*.version-metadata
 ----------------------------
 Type
     ``string``
-Default
-    ``null``
 Description
     Insert an ``object`` containing gallery-dl's version info into
     metadata dictionaries as the given name.

gallery_dl/extractor/common.py

@@ -78,6 +78,12 @@ class Extractor():
     def config(self, key, default=None):
         return config.interpolate(self._cfgpath, key, default)
 
+    def config2(self, key, key2, default=None, sentinel=util.SENTINEL):
+        value = self.config(key, sentinel)
+        if value is not sentinel:
+            return value
+        return self.config(key2, default)
+
     def config_deprecated(self, key, deprecated, default=None,
                           sentinel=util.SENTINEL, history=set()):
         value = self.config(deprecated, sentinel)

gallery_dl/job.py

@@ -87,11 +87,10 @@ class Job():
                 extr.category = pextr.category
                 extr.subcategory = pextr.subcategory
 
-        self.metadata_url = extr.config("url-metadata")
-        self.metadata_http = extr.config("http-metadata")
-
-        version_info = extr.config("version-metadata")
-        metadata_path = extr.config("path-metadata")
+        self.metadata_url = extr.config2("metadata-url", "url-metadata")
+        self.metadata_http = extr.config2("metadata-http", "http-metadata")
+        metadata_path = extr.config2("metadata-path", "path-metadata")
+        metadata_version = extr.config2("metadata-version", "version-metadata")
 
         # user-supplied metadata
         kwdict = extr.config("keywords")
@@ -99,8 +98,8 @@ class Job():
             self.kwdict.update(kwdict)
         if metadata_path:
             self.kwdict[metadata_path] = path_proxy
-        if version_info:
-            self.kwdict[version_info] = {
+        if metadata_version:
+            self.kwdict[metadata_version] = {
                 "version"         : version.__version__,
                 "is_executable"   : util.EXECUTABLE,
                 "current_git_head": util.git_head()
@@ -375,7 +374,7 @@ class DownloadJob(Job):
             else:
                 extr._parentdir = pextr._parentdir
 
-            pmeta = pextr.config("parent-metadata")
+            pmeta = pextr.config2("parent-metadata", "metadata-parent")
             if pmeta:
                 if isinstance(pmeta, str):
                     data = self.kwdict.copy()