1
#!/usr/bin/env python3
2
"""A simple example cmd2 application demonstrating many common features.
3

4
Features demonstrated include all of the following:
5
 1) Colorizing/stylizing output
6
 2) Using multiline commands
7
 3) Persistent history
8
 4) How to run an initialization script at startup
9
 5) How to group and categorize commands when displaying them in help
10
 6) Opting-in to using the ipy command to run an IPython shell
11
 7) Allowing access to your application in py and ipy
12
 8) Displaying an intro banner upon starting your application
13
 9) Using a custom prompt
14
10) How to make custom attributes settable at runtime.
15
11) Shortcuts for commands
16
12) Persistent bottom toolbar with realtime status updates
17
"""
18

19
import pathlib
20
import threading
21
import time
22

23
from prompt_toolkit.formatted_text import FormattedText
24
from rich.style import Style
25

26
import cmd2
27
from cmd2 import (
28
    Color,
29
    stylize,
30
)
31

32

33
class BasicApp(cmd2.Cmd):
34
    """Cmd2 application to demonstrate many common features."""
35

36
    DEFAULT_CATEGORY = "My Custom Commands"
37

38
    def __init__(self) -> None:
39
        """Initialize the cmd2 application."""
40
        # Startup script that defines a couple aliases for running shell commands
41
        alias_script = pathlib.Path(__file__).absolute().parent / ".cmd2rc"
42

43
        # Create a shortcut for one of our commands
44
        shortcuts = cmd2.DEFAULT_SHORTCUTS
45
        shortcuts.update({"&": "intro"})
46
        super().__init__(
47
            auto_suggest=True,
48
            bottom_toolbar=True,
49
            include_ipy=True,
50
            multiline_commands=["echo"],
51
            persistent_history_file="cmd2_history.dat",
52
            shortcuts=shortcuts,
53
            startup_script=str(alias_script),
54
        )
55

56
        # Spawn a background thread to refresh the bottom toolbar twice a second.
57
        # This is necessary because the toolbar contains a timestamp that we want to keep current.
58
        self._stop_refresh = False
59
        self._refresh_thread = threading.Thread(target=self._refresh_bottom_toolbar, daemon=True)
60
        self._refresh_thread.start()
61

62
        # Prints an intro banner once upon application startup
63
        self.intro = (
64
            stylize(
65
                "Welcome to cmd2!",
66
                style=Style(color=Color.GREEN1, bgcolor=Color.GRAY0, bold=True),
67
            )
68
            + " Note the full Unicode support:  😇 💩"
69
            + " and the persistent bottom bar with realtime status updates!"
70
        )
71

72
        # Show this as the prompt when asking for input
73
        self.prompt = "myapp> "
74

75
        # Used as prompt for multiline commands after the first line
76
        self.continuation_prompt = "... "
77

78
        # Allow access to your application in py and ipy via self
79
        self.self_in_py = True
80

81
        # Color to output text in with echo command
82
        self.foreground_color = Color.CYAN.value
83

84
        # Make echo_fg settable at runtime
85
        fg_colors = [c.value for c in Color]
86
        self.add_settable(
87
            cmd2.Settable(
88
                "foreground_color",
89
                str,
90
                "Foreground color to use with echo command",
91
                self,
92
                choices=fg_colors,
93
            )
94
        )
95

96
    def get_rprompt(self) -> str | FormattedText | None:
97
        current_working_directory = pathlib.Path.cwd()
98
        style = "bg:ansired fg:ansiwhite"
99
        text = f"cwd={current_working_directory}"
100
        return FormattedText([(style, text)])
101

102
    def _refresh_bottom_toolbar(self) -> None:
103
        """Background thread target to refresh the bottom toolbar.
104

105
        This is a toy example to show how the bottom toolbar can be used to display
106
        realtime status updates in an otherwise line-oriented command interpreter.
107
        """
108
        import contextlib
109

110
        from prompt_toolkit.application.current import get_app
111

112
        while not self._stop_refresh:
113
            with contextlib.suppress(Exception):
114
                # get_app() will return the currently running prompt-toolkit application
115
                app = get_app()
116
                if app:
117
                    app.invalidate()
118
            time.sleep(0.5)
119

120
    def do_intro(self, _: cmd2.Statement) -> None:
121
        """Display the intro banner."""
122
        self.poutput(self.intro)
123

124
    def do_echo(self, arg: cmd2.Statement) -> None:
125
        """Multiline command."""
126
        self.poutput(
127
            stylize(
128
                arg,
129
                style=Style(color=self.foreground_color),
130
            )
131
        )
132

133

134
if __name__ == "__main__":
135
    import sys
136

137
    app = BasicApp()
138
    sys.exit(app.cmdloop())