play plugin: $playlist marker for precise control where the playlist … (#4728)

…file is placed in the command

## Description

see included doc; placing the playlist filename at the end of command
just isn't working for all players

I have this in use with `mpv`

Co-authored-by: cvx35isl <cvx35isl@users.noreply.github.com>
Co-authored-by: J0J0 Todos <2733783+JOJ0@users.noreply.github.com>

beetsplug/play.py

@@ -28,6 +28,11 @@ from beets.util import get_temp_filename
 # If this is missing, they're placed at the end.
 ARGS_MARKER = "$args"
 
+# Indicate where the playlist file (with absolute path) should be inserted into
+# the command string. If this is missing, its placed at the end, but before
+# arguments.
+PLS_MARKER = "$playlist"
+
 
 def play(
     command_str,
@@ -132,8 +137,23 @@ class PlayPlugin(BeetsPlugin):
             return
 
         open_args = self._playlist_or_paths(paths)
+        open_args_str = [
+            p.decode("utf-8") for p in self._playlist_or_paths(paths)
+        ]
         command_str = self._command_str(opts.args)
 
+        if PLS_MARKER in command_str:
+            if not config["play"]["raw"]:
+                command_str = command_str.replace(
+                    PLS_MARKER, "".join(open_args_str)
+                )
+                self._log.debug(
+                    "command altered by PLS_MARKER to: {}", command_str
+                )
+                open_args = []
+            else:
+                command_str = command_str.replace(PLS_MARKER, " ")
+
         # Check if the selection exceeds configured threshold. If True,
         # cancel, otherwise proceed with play command.
         if opts.yes or not self._exceeds_threshold(
@@ -162,6 +182,7 @@ class PlayPlugin(BeetsPlugin):
             return paths
         else:
             return [self._create_tmp_playlist(paths)]
+            return [shlex.quote(self._create_tmp_playlist(paths))]
 
     def _exceeds_threshold(
         self, selection, command_str, open_args, item_type="track"

docs/changelog.rst

@@ -10,6 +10,8 @@ Unreleased
 New features:
 
 - :doc:`plugins/ftintitle`: Added argument for custom feat. words in ftintitle.
+- :doc: `/plugins/play`: Added `$playlist` marker to precisely edit the playlist
+      filepath into the command calling the player program.
 
 Bug fixes:
 
@@ -71,6 +73,8 @@ New features:
   :bug:`3354`
 - :doc:`plugins/discogs` Support for name variations and config options to
   specify where the variations are written. :bug:`3354`
+- :doc: `/plugins/play`: Added `$playlist` marker to precisely edit the playlist
+      filepath into the command calling the player program.
 
 Bug fixes:
 

docs/plugins/play.rst

@@ -107,6 +107,15 @@ string, use ``$args`` to indicate where to insert them. For example:
 indicates that you need to insert extra arguments before specifying the
 playlist.
 
+Some players require a different syntax. For example, with ``mpv`` the optional
+``$playlist`` variable can be used to match the syntax of the ``--playlist``
+option:
+
+::
+
+    play:
+        command: mpv $args --playlist=$playlist
+
 The ``--yes`` (or ``-y``) flag to the ``play`` command will skip the warning
 message if you choose to play more items than the **warning_threshold** value
 usually allows.

test/plugins/test_play.py

@@ -105,6 +105,19 @@ class PlayPluginTest(CleanupModulesMixin, PluginTestCase):
 
         open_mock.assert_called_once_with([self.item.path], "echo")
 
+    def test_pls_marker(self, open_mock):
+        self.config["play"]["command"] = (
+            "echo --some params --playlist=$playlist --some-more params"
+        )
+
+        self.run_command("play", "nice")
+
+        open_mock.assert_called_once
+
+        commandstr = open_mock.call_args_list[0][0][1]
+        assert commandstr.startswith("echo --some params --playlist=")
+        assert commandstr.endswith(" --some-more params")
+
     def test_not_found(self, open_mock):
         self.run_command("play", "not found")