"""
EvMenu
This implements a full menu system for Evennia. It is considerably
more flexible than the older contrib/menusystem.py and also uses
menu plugin modules.
To start the menu, just import the EvMenu class from this module,
```python
from evennia.utils.evmenu import EvMenu
EvMenu(caller, menu_module_path,
startnode="node1",
cmdset_mergetype="Replace", cmdset_priority=1,
allow_quit=True, cmd_on_quit="look")
```
Where `caller` is the Object to use the menu on - it will get a new
cmdset while using the Menu. The menu_module_path is the python path
to a python module containing function defintions. By adjusting the
keyword options of the Menu() initialization call you can start the
menu at different places in the menu definition file, adjust if the
menu command should overload the normal commands or not, etc.
The menu is defined in a module (this can be the same module as the
command definition too) with function defintions:
```python
def node1(caller):
# (this is the start node if called like above)
# code
return text, options
def node_with_other_namen(caller, input_string):
# code
return text, options
```
Where caller is the object using the menu and input_string is the
command entered by the user on the *previous* node (the command
entered to get to this node). The node function code will only be
executed once per node-visit and the system will accept nodes with
both one or two arguments interchangeably.
The menu tree itself is available on the caller as
`caller.ndb._menutree`. This makes it a convenient place to store
temporary state variables between nodes, since this NAttribute is
deleted when the menu is exited.
The return values must be given in the above order, but each can be
returned as None as well. If the options are returned as None, the
menu is immediately exited and the default "look" command is called.
text (str, tuple or None): Text shown at this node. If a tuple, the
second element in the tuple is a help text to display at this
node when the user enters the menu help command there.
options (tuple, dict or None): (
{'key': name, # can also be a list of aliases. A special key is
# "_default", which marks this option as the default
# fallback when no other option matches the user input.
'desc': description, # optional description
'goto': nodekey, # node to go to when chosen
'exec': nodekey}, # node or callback to trigger as callback when chosen.
# If a node key is given, the node will be executed once
# but its return values are ignored. If a callable is
# given, it must accept one or two args, like any node.
{...}, ...)
If key is not given, the option will automatically be identified by
its number 1..N.
Example:
```python
# in menu_module.py
def node1(caller):
text = ("This is a node text",
"This is help text for this node")
options = ({"key": "testing",
"desc": "Select this to go to node 2",
"goto": "node2",
"exec": "callback1"},
{"desc": "Go to node 3.",
"goto": "node3"})
return text, options
def callback1(caller):
# this is called when choosing the "testing" option in node1
# (before going to node2). It needs not have return values.
caller.msg("Callback called!")
def node2(caller):
text = '''
This is node 2. It only allows you to go back
to the original node1. This extra indent will
be stripped. We don't include a help text.
'''
options = {"goto": "node1"}
return text, options
def node3(caller):
text = "This ends the menu since there are no options."
return text, None
```
When starting this menu with `Menu(caller, "path.to.menu_module")`,
the first node will look something like this:
This is a node text
______________________________________
testing: Select this to go to node 2
2: Go to node 3
Where you can both enter "testing" and "1" to select the first option.
If the client supports MXP, they may also mouse-click on "testing" to
do the same. When making this selection, a function "callback1" in the
same Using `help` will show the help text, otherwise a list of
available commands while in menu mode.
The menu tree is exited either by using the in-menu quit command or by
reaching a node without any options.
For a menu demo, import CmdTestMenu from this module and add it to
your default cmdset. Run it with this module, like `testmenu
evennia.utils.evmenu`.
"""
from textwrap import dedent
from inspect import isfunction, getargspec
from django.conf import settings
from evennia import Command, CmdSet
from evennia.utils.evtable import EvTable
from evennia.utils.ansi import ANSIString, strip_ansi
from evennia.utils.utils import mod_import, make_iter, pad, m_len
from evennia.commands import cmdhandler
# read from protocol NAWS later?
_MAX_TEXT_WIDTH = settings.CLIENT_DEFAULT_WIDTH
# we use cmdhandler instead of evennia.syscmdkeys to
# avoid some cases of loading before evennia init'd
_CMD_NOMATCH = cmdhandler.CMD_NOMATCH
_CMD_NOINPUT = cmdhandler.CMD_NOINPUT
# Return messages
# i18n
from django.utils.translation import ugettext as _
_ERR_NOT_IMPLEMENTED = _("Menu node '{nodename}' is not implemented. Make another choice.")
_ERR_GENERAL = _("Error in menu node '{nodename}'.")
_ERR_NO_OPTION_DESC = _("No description.")
_HELP_FULL = _("Commands: