Added capability to override the argument parser class used by cmd2 built-in commands

1 files changed, 24 insertions, 0 deletions

diff --git a/examples/override_parser.py b/examples/override_parser.py
new file mode 100755
index 00000000..ddfa8323
--- /dev/null
+++ b/examples/override_parser.py
@@ -0,0 +1,24 @@
+#!/usr/bin/env python
+# coding=utf-8
+# flake8: noqa F402
+"""
+The standard parser used by cmd2 built-in commands is Cmd2ArgumentParser.
+The following code shows how to override it with your own parser class.
+"""
+
+# First set a value called argparse.cmd2_parser_module with the module that defines the custom parser
+# See the code for custom_parser.py. It simply defines a parser and calls cmd2.set_default_argument_parser()
+# with the custom parser's type.
+import argparse
+argparse.cmd2_parser_module = 'examples.custom_parser'
+
+# Next import stuff from cmd2. It will import your module just before the cmd2.Cmd class file is imported
+# and therefore override the parser class it uses on its commands.
+from cmd2 import cmd2
+
+if __name__ == '__main__':
+    import sys
+    app = cmd2.Cmd(use_ipython=True, persistent_history_file='cmd2_history.dat')
+    app.locals_in_py = True     # Enable access to "self" within the py command
+    app.debug = True            # Show traceback if/when an exception occurs
+    sys.exit(app.cmdloop())