projects.mk / jw-projects.py: Support tmpl_dir && tmpls-dir

For a project to supply templates, it needs to advertise their
location. For this, the tmpl_dir make variable is added to
projects.mk. If other-project wants to get hold of some-project's
templates, it can do, e.g.:

  TEMPLATES = $(wilcard $(call tmpl_dir,some-project)/*.tmpl)

To achieve this, support for the tmpls-dir command is added to
jw-projects.py.

Signed-off-by: Jan Lindemann <jan@janware.com>

src/python/jw/pkg/build/cmds/CmdTmplDir.py

@@ -0,0 +1,20 @@
+# -*- coding: utf-8 -*-
+
+from argparse import Namespace, ArgumentParser
+
+from ..Cmd import Cmd
+
+class CmdTmplDir(Cmd): # export
+
+    def __init__(self) -> None:
+        super().__init__('tmpl-dir', help='Print directory containing templates of a given module')
+
+    def add_arguments(self, parser: ArgumentParser) -> None:
+        super().add_arguments(parser)
+        parser.add_argument('module', nargs='*', help='Modules')
+
+    def _run(self, args: Namespace) -> None:
+        r = []
+        for m in args.module:
+            r.append(self.app.tmpl_dir(m))
+        print(' '.join(r))