Coverage for /pythoncovmergedfiles/medio/medio/usr/local/lib/python3.8/site-packages/prompt_toolkit/application/current.py: 39%
70 statements
« prev ^ index » next coverage.py v7.2.2, created at 2023-03-26 06:07 +0000
1from __future__ import annotations
3import sys
4from contextlib import contextmanager
5from contextvars import ContextVar
6from typing import TYPE_CHECKING, Any, Generator, Optional
8if TYPE_CHECKING:
9 from prompt_toolkit.input.base import Input
10 from prompt_toolkit.output.base import Output
12 from .application import Application
14__all__ = [
15 "AppSession",
16 "get_app_session",
17 "get_app",
18 "get_app_or_none",
19 "set_app",
20 "create_app_session",
21 "create_app_session_from_tty",
22]
25class AppSession:
26 """
27 An AppSession is an interactive session, usually connected to one terminal.
28 Within one such session, interaction with many applications can happen, one
29 after the other.
31 The input/output device is not supposed to change during one session.
33 Warning: Always use the `create_app_session` function to create an
34 instance, so that it gets activated correctly.
36 :param input: Use this as a default input for all applications
37 running in this session, unless an input is passed to the `Application`
38 explicitely.
39 :param output: Use this as a default output.
40 """
42 def __init__(
43 self, input: Input | None = None, output: Output | None = None
44 ) -> None:
45 self._input = input
46 self._output = output
48 # The application will be set dynamically by the `set_app` context
49 # manager. This is called in the application itself.
50 self.app: Application[Any] | None = None
52 def __repr__(self) -> str:
53 return f"AppSession(app={self.app!r})"
55 @property
56 def input(self) -> Input:
57 if self._input is None:
58 from prompt_toolkit.input.defaults import create_input
60 self._input = create_input()
61 return self._input
63 @property
64 def output(self) -> Output:
65 if self._output is None:
66 from prompt_toolkit.output.defaults import create_output
68 self._output = create_output()
69 return self._output
72_current_app_session: ContextVar[AppSession] = ContextVar(
73 "_current_app_session", default=AppSession()
74)
77def get_app_session() -> AppSession:
78 return _current_app_session.get()
81def get_app() -> Application[Any]:
82 """
83 Get the current active (running) Application.
84 An :class:`.Application` is active during the
85 :meth:`.Application.run_async` call.
87 We assume that there can only be one :class:`.Application` active at the
88 same time. There is only one terminal window, with only one stdin and
89 stdout. This makes the code significantly easier than passing around the
90 :class:`.Application` everywhere.
92 If no :class:`.Application` is running, then return by default a
93 :class:`.DummyApplication`. For practical reasons, we prefer to not raise
94 an exception. This way, we don't have to check all over the place whether
95 an actual `Application` was returned.
97 (For applications like pymux where we can have more than one `Application`,
98 we'll use a work-around to handle that.)
99 """
100 session = _current_app_session.get()
101 if session.app is not None:
102 return session.app
104 from .dummy import DummyApplication
106 return DummyApplication()
109def get_app_or_none() -> Application[Any] | None:
110 """
111 Get the current active (running) Application, or return `None` if no
112 application is running.
113 """
114 session = _current_app_session.get()
115 return session.app
118@contextmanager
119def set_app(app: Application[Any]) -> Generator[None, None, None]:
120 """
121 Context manager that sets the given :class:`.Application` active in an
122 `AppSession`.
124 This should only be called by the `Application` itself.
125 The application will automatically be active while its running. If you want
126 the application to be active in other threads/coroutines, where that's not
127 the case, use `contextvars.copy_context()`, or use `Application.context` to
128 run it in the appropriate context.
129 """
130 session = _current_app_session.get()
132 previous_app = session.app
133 session.app = app
134 try:
135 yield
136 finally:
137 session.app = previous_app
140@contextmanager
141def create_app_session(
142 input: Input | None = None, output: Output | None = None
143) -> Generator[AppSession, None, None]:
144 """
145 Create a separate AppSession.
147 This is useful if there can be multiple individual `AppSession`s going on.
148 Like in the case of an Telnet/SSH server. This functionality uses
149 contextvars and requires at least Python 3.7.
150 """
151 if sys.version_info <= (3, 6):
152 raise RuntimeError("Application sessions require Python 3.7.")
154 # If no input/output is specified, fall back to the current input/output,
155 # whatever that is.
156 if input is None:
157 input = get_app_session().input
158 if output is None:
159 output = get_app_session().output
161 # Create new `AppSession` and activate.
162 session = AppSession(input=input, output=output)
164 token = _current_app_session.set(session)
165 try:
166 yield session
167 finally:
168 _current_app_session.reset(token)
171@contextmanager
172def create_app_session_from_tty() -> Generator[AppSession, None, None]:
173 """
174 Create `AppSession` that always prefers the TTY input/output.
176 Even if `sys.stdin` and `sys.stdout` are connected to input/output pipes,
177 this will still use the terminal for interaction (because `sys.stderr` is
178 still connected to the terminal).
180 Usage::
182 from prompt_toolkit.shortcuts import prompt
184 with create_app_session_from_tty():
185 prompt('>')
186 """
187 from prompt_toolkit.input.defaults import create_input
188 from prompt_toolkit.output.defaults import create_output
190 input = create_input(always_prefer_tty=True)
191 output = create_output(always_prefer_tty=True)
193 with create_app_session(input=input, output=output) as app_session:
194 yield app_session