From 44c074d27a60f46f378b12b79d2f2f16f30b6b21 Mon Sep 17 00:00:00 2001
From: Richard Terry <git@radiac.net>
Date: Sun, 21 Apr 2024 08:31:50 +0100
Subject: [PATCH] Add support for calling app.run() within the script

---
 docs/management.rst    | 64 ++++++++++++++++++++++++++++++++++++++++++
 examples/scale.py      |  7 +++++
 nanodjango/app.py      | 20 ++++++++++++-
 nanodjango/commands.py |  8 +++---
 4 files changed, 94 insertions(+), 5 deletions(-)

diff --git a/docs/management.rst b/docs/management.rst
index 9896855..2ffc157 100644
--- a/docs/management.rst
+++ b/docs/management.rst
@@ -30,3 +30,67 @@ nanodjango uses the filename as the app name - eg:
 .. code-block:: bash
 
     nanodjango counter.py run makemigrations counter
+
+
+.. _run_script:
+
+Running your script directly
+============================
+
+You don't need to use the ``nanodjango`` command - you can call ``app.run()`` from the
+bottom of your script, eg:
+
+.. code-block:: python
+
+    from nanodjango import Django
+    app = Django()
+    ...
+    if __name__ == "__main__":
+        app.run()
+
+You can then run the script directly to launch the Django development server. This will
+also automatically collect any arguments you may have passed on the command line::
+
+    python hello.py run runserver 0:8004
+
+
+Running it as a standalone script
+---------------------------------
+
+You can take it a step further and add a [PEP 723](https://peps.python.org/pep-0723/)
+comment to the top to specify ``nanodjango`` as a dependency:
+
+.. code-block:: python
+
+    # /// script
+    # dependencies = ["nanodjango"]
+    # ///
+    from nanodjango import Django
+    app = Django()
+    ...
+    if __name__ == "__main__":
+        app.run()
+
+This will allow you to pass it to ``pipx run``, to run your development server without
+installing anything first:
+
+.. code-block:: bash
+
+    # Create a temporary venv with ``nanodjango`` installed, then run the script
+    pipx run ./script.py
+
+    # Pass some arguments
+    pipx run ./script.py -- runserver 0:8000
+
+
+Running in production
+---------------------
+
+The commands above are suitable for running the Django development server locally, but
+are not appropriate for use in production.
+
+Instead, you can pass nanodjango's ``app = Django()`` to a WSGI server:
+
+.. code-block:: bash
+
+    gunicorn -w 4 counter:app
diff --git a/examples/scale.py b/examples/scale.py
index 2bcd347..8ee3481 100644
--- a/examples/scale.py
+++ b/examples/scale.py
@@ -12,6 +12,9 @@
     cd /path/to/site
     ./manage.py runserver 0:8000
 """
+# /// script
+# dependencies = ["nanodjango"]
+# ///
 
 import os
 
@@ -83,3 +86,7 @@ class Counts(ListView):
 
 def something(name):
     return os.getenv(name)
+
+
+if __name__ == "__main__":
+    app.run()
diff --git a/nanodjango/app.py b/nanodjango/app.py
index 7af0d26..b7910b0 100644
--- a/nanodjango/app.py
+++ b/nanodjango/app.py
@@ -166,13 +166,31 @@ def wrap(model: type[Model]):
         # Called without arguments, @admin - call wrapped immediately
         return wrap(model)
 
-    def run(self, args: list[str]):
+    def run(self, args: list[str] | None = None):
         """
         Run a Django management command, passing all arguments
 
         Defaults to:
             runserver 0:8000
         """
+        # Check if this is being called from click commands or directly
+        if self.app_name not in sys.modules:
+            # Hasn't been run through the ``nanodjango`` command
+            if (
+                "__main__" not in sys.modules
+                or getattr(sys.modules["__main__"], "app") != self
+            ):
+                # Doesn't look like it was run directly either
+                raise UsageError("App module not initialised")
+
+            # Run directly, so register app module so Django won't try to load it again
+            sys.modules[self.app_name] = sys.modules["__main__"]
+
+        # Be helpful and check sys.argv for args. This will almost certainly be because
+        # it's running directly.
+        if args is None:
+            args = sys.argv[1:]
+
         self._prepare()
         from django.core.management import execute_from_command_line
 
diff --git a/nanodjango/commands.py b/nanodjango/commands.py
index 32f10e9..1917e97 100644
--- a/nanodjango/commands.py
+++ b/nanodjango/commands.py
@@ -40,11 +40,11 @@ def run(ctx, args: tuple[str]):
 )
 @click.pass_context
 def convert(ctx, path: click.Path, name: str, can_delete: bool = False):
-    path: Path = Path(str(path)).resolve()
-    if can_delete and path.exists():
-        shutil.rmtree(str(path))
+    target_path: Path = Path(str(path)).resolve()
+    if can_delete and target_path.exists():
+        shutil.rmtree(str(target_path))
 
-    ctx.obj["app"].convert(path, name)
+    ctx.obj["app"].convert(target_path, name)
 
 
 def invoke():