EvMenu

Introduction

The EvMenu utility class is located in
It allows for easily adding interactive menus to the game; for example to implement Character
creation, building commands or similar. Below is an example of offering NPC conversation choices:
The guard looks at you suspiciously.
"No one is supposed to be in here ..."
he says, a hand on his weapon.
_______________________________________________
 1. Try to bribe him [Cha + 10 gold]
 2. Convince him you work here [Int]
 3. Appeal to his vanity [Cha]
 4. Try to knock him out [Luck + Dex]
 5. Try to run away [Dex]
This is an example of a menu node. Think of a node as a point where the menu stops printing text
and waits for user to give some input. By jumping to different nodes depending on the input, a menu
is constructed.
To create the menu, EvMenu uses normal Python functions, one per node. It will load all those
functions/nodes either from a module or by being passed a dictionary mapping the node’s names to
said functions, like {"nodename": <function>, ...}

Launching the menu

Initializing the menu is done using a call to the evennia.utils.evmenu.EvMenu class. This is the
most common way to do so - from inside a Command:
# in, for example gamedir/commands/command.py

from evennia.utils.evmenu import EvMenu

class CmdTestMenu(Command):

    key = "testcommand"

    def func(self):

    EvMenu(caller, "world.mymenu")
When running this command, the menu will start using the menu nodes loaded from
mygame/world/mymenu.py. See next section on how to define menu nodes.

The EvMenu has the following optional callsign:

EvMenu(caller, menu_data,
       startnode="start",
       cmdset_mergetype="Replace", cmdset_priority=1,
       auto_quit=True, auto_look=True, auto_help=True,
       cmd_on_exit="look",
       persistent=False,
       startnode_input="",
       session=None,
       debug=False,
       **kwargs)
  • caller (Object or Account): is a reference to the object using the menu. This object will get a new CmdSet assigned to it, for handling the menu.
  • menu_data (str, module or dict): is a module or python path to a module where the global-level functions will each be considered to be a menu node. Their names in the module will be the names by which they are referred to in the module. Importantly, function names starting with an underscore _ will be ignored by the loader. Alternatively, this can be a direct mapping {"nodename":function, ...}.
  • startnode (str): is the name of the menu-node to start the menu at. Changing this means that you can jump into a menu tree at different positions depending on circumstance and thus possibly re-use menu entries.
  • cmdset_mergetype (str): This is usually one of “Replace” or “Union” (see CmdSets. The first means that the menu is exclusive - the user has no access to any other commands while in the menu. The Union mergetype means the menu co-exists with previous commands (and may overload them, so be careful as to what to name your menu entries in this case).
  • cmdset_priority (int): The priority with which to merge in the menu cmdset. This allows for advanced usage.
  • auto_quit, auto_look, auto_help (bool): If either of these are True, the menu automatically makes a quit, look or help command available to the user. The main reason why you’d want to turn this off is if you want to use the aliases “q”, “l” or “h” for something in your menu. Nevertheless, at least quit is highly recommend - if False, the menu must itself supply an “exit node” (a node without any options), or the user will be stuck in the menu until the server reloads (or eternally if the menu is persistent)!
  • cmd_on_exit (str): This command string will be executed right after the menu has closed down. From experience, it’s useful to trigger a “look” command to make sure the user is aware of the change of state; but any command can be used. If set to None, no command will be triggered after exiting the menu.
  • persistent (bool) - if True, the menu will survive a reload (so the user will not be kicked out by the reload - make sure they can exit on their own!)
  • startnode_input (str or (str, dict) tuple): Pass an input text or a input text + kwargs to the start node as if it was entered on a fictional previous node. This can be very useful in order to start a menu differently depending on the Command’s arguments in which it was initialized.
  • session (Session): Useful when calling the menu from an Account in MULTISESSION_MODDE higher than 2, to make sure only the right Session sees the menu output.
  • debug (bool): If set, the menudebug command will be made available in the menu. Use it to list the current state of the menu and use menudebug <variable> to inspect a specific state variable from the list.
  • All other keyword arguments will be available as initial data for the nodes. They will be available in all nodes as properties on caller.ndb._menutree (see below). These will also survive a @reload if the menu is persistent.
You don’t need to store the EvMenu instance anywhere - the very act of initializing it will store it
as caller.ndb._menutree on the caller. This object will be deleted automatically when the menu
is exited and you can also use it to store your own temporary variables for access throughout the
menu. Temporary variables you store on a persistent _menutree as it runs will
not survive a @reload, only those you set as part of the original EvMenu call.

The Menu nodes

The EvMenu nodes consist of functions on one of these forms.

def menunodename1(caller):
    # code
    return text, options

def menunodename2(caller, raw_string):
    # code
    return text, options

def menunodename3(caller, raw_string, **kwargs):
    # code
    return text, options

| While all of the above forms are okay, it’s recommended to stick
  to the third and last form since it
| gives the most flexibility. The previous forms are mainly there
  for backwards compatibility with
| existing menus from a time when EvMenu was less able.

Input arguments to the node

  • caller (Object or Account): The object using the menu - usually a Character but could also be a Session or Account depending on where the menu is used.
  • raw_string (str): If this is given, it will be set to the exact text the user entered on the previous node (that is, the command entered to get to this node). On the starting-node of the menu, this will be an empty string, unless startnode_input was set.
  • kwargs (dict): These extra keyword arguments are extra optional arguments passed to the node when the user makes a choice on the previous node. This may include things like status flags and details about which exact option was chosen (which can be impossible to determine from raw_string alone). Just what is passed in kwargs is up to you when you create the previous node.

Return values from the node

Each function must return two variables, text and options.

text

The text variable is a string or tuple. This text is what will be displayed when the user reaches
this node. If this is a tuple, then the first element of the tuple will be considered the displayed
text and the second the help-text to display when the user enters the help command on this node.
text = ("This is the text to display", "This is the help text for this node")
Returning a None text is allowed and simply leads to a node with no text and only options. If the
help text is not given, the menu will give a generic error message when using help.

options

The options list describe all the choices available to the user when viewing this node. If options is
returned as None, it means that this node is an Exit node - any text is displayed and then the
menu immediately exits, running the exit_cmd if given.
Otherwise, options should be a list (or tuple) of dictionaries, one for each option. If only one option is
available, a single dictionary can also be returned. This is how it could look:
def node_test(caller, raw_string, **kwargs):

    text = "A goblin attacks you!"

    options = (
    {"key": ("Attack", "a", "att"),
         "desc": "Strike the enemy with all your might",
         "goto": "node_attack"},
    {"key": ("Defend", "d", "def"),
         "desc": "Hold back and defend yourself",
         "goto": (_defend, {"str": 10, "enemyname": "Goblin"})})

    return text, options

This will produce a menu node looking like this:

A goblin attacks you!
________________________________

Attack: Strike the enemy with all your might
Defend: Hold back and defend yourself
option-key ‘key’
The option’s key is what the user should enter in order to choose that option. If given as a tuple, the
first string of that tuple will be what is shown on-screen while the rest are aliases for picking
that option. In the above example, the user could enter “Attack” (or “attack”, it’s not
case-sensitive), “a” or “att” in order to attack the goblin. Aliasing is useful for adding custom
coloring to the choice. The first element of the aliasing tuple should then be the colored version,
followed by a version without color - since otherwise the user would have to enter the color codes
to select that choice.
Note that the key is optional. If no key is given, it will instead automatically be replaced
with a running number starting from 1. If removing the key part of each option, the resulting
menu node would look like this instead:
A goblin attacks you!
________________________________

1: Strike the enemy with all your might
2: Hold back and defend yourself
Whether you want to use a key or rely on numbers is mostly
a matter of style and the type of menu.
EvMenu accepts one important special key given only as "_default". This key is used when a user
enters something that does not match any other fixed keys. It is particularly useful for getting
user input:
def node_readuser(caller, raw_string, **kwargs):
    text = "Please enter your name"

    options = {"key": "_default",
               "goto": "node_parse_input"}

    return text, options
A "_default" option does not show up in the menu, so the above will just be a node saying
"Please enter your name". The name they entered will appear as raw_string in the next node.

option-key ‘desc’

This simply contains the description as to what happens when selecting the menu option. For
"_default" options or if the key is already long or descriptive, it is not strictly needed. But
usually it’s better to keep the key short and put more detail in desc.

option-key ‘goto’

This is the operational part of the option and fires only when the user chooses said option. Here
are three ways to write it
def _action_two(caller, raw_string, **kwargs):
    # do things ...
    return calculated_node_to_go_to

def _action_three(caller, raw_string, **kwargs):
    # do things ...
    return "node_four", {"mode": 4}


def node_select(caller, raw_string, **kwargs):

    text = ("select one",
            "help: they all do different things ...")

    options = ({"desc": "Option one",
        "goto": "node_one"},
           {"desc": "Option two",
        "goto": _action_two}
           {"desc": "Option three",
        "goto": (_action_three, {"key": 1, "key2": 2})

    return text, options
As seen above, goto could just be pointing to a single nodename string - the name of the node to
go to. When given like this, EvMenu will look for a node named like this and call its associated
function as
nodename(caller, raw_string, **kwargs)`
Here, raw_string is always the input the user entered to make that choice and kwargs are the
same as those kwargs that already entered the current node (they are passed on).
Alternatively the goto could point to a “goto-callable”. Such callables are usually defined in the same
module as the menu nodes and given names starting with _ (to avoid being parsed as nodes
themselves). These callables will be called the same as a node function - callable(caller, raw_string, **kwargs), where raw_string is what the user entered on this node and **kwargs is
forwarded from the node’s own input.
The goto option key could also point to a tuple (callable, kwargs) - this allows for customizing
the kwargs passed into the goto-callable, for example you could use the same callable but change the
kwargs passed into it depending on which option was actually chosen.
The “goto callable” must either return a string "nodename" or a tuple ("nodename", mykwargs).
This will lead to the next node being called as either nodename(caller, raw_string, **kwargs) or
nodename(caller, raw_string, **mykwargs) - so this allows changing (or replacing) the options going
into the next node depending on what option was chosen.
There is one important case - if the goto-callable returns None for a nodename, the current node will run again, possibly with different kwargs. This makes it very easy to re-use a node over
and over, for example allowing different options to update some text form being passed and
manipulated for every iteration.
The EvMenu also supports the exec option key. This allows for running a callable before the
goto-callable. This functionality comes from a time before goto could be a callable and is
deprecated as of Evennia 0.8. Use goto for all functionality where you’d before use exec.

Temporary storage

When the menu starts, the EvMenu instance is stored on the caller as caller.ndb._menutree. Through
this object you can in principle reach the menu’s internal state if you know what you are doing.
This is also a good place to store temporary, more global variables that may be cumbersome to keep
passing from node to node via the **kwargs. The _menutree will be deleted automatically when the
menu closes, meaning you don’t need to worry about cleaning anything up.
If you want permanent state storage, it’s instead better to use an Attribute on caller. Remember
that this will remain after the menu closes though, so you need to handle any needed cleanup
yourself.

Customizing Menu formatting

The EvMenu display of nodes, options etc are controlled by a series of formatting methods on the
EvMenu class. To customize these, simply create a new child class of EvMenu and override as
needed. Here is an example:
from evennia.utils.evmenu import EvMenu

class MyEvMenu(EvMenu):

    def nodetext_formatter(self, nodetext):
        """
        Format the node text itself.

        Args:
            nodetext (str): The full node text (the text describing the node).

        Returns:
            nodetext (str): The formatted node text.

        """

    def helptext_formatter(self, helptext):
        """
        Format the node's help text

        Args:
            helptext (str): The unformatted help text for the node.

        Returns:
            helptext (str): The formatted help text.

        """

    def options_formatter(self, optionlist):
        """
        Formats the option block.

        Args:
            optionlist (list): List of (key, description) tuples for every
                option related to this node.
            caller (Object, Account or None, optional): The caller of the node.

        Returns:
            options (str): The formatted option display.

        """

    def node_formatter(self, nodetext, optionstext):
        """
        Formats the entirety of the node.

        Args:
            nodetext (str): The node text as returned by `self.nodetext_formatter`.
            optionstext (str): The options display as returned by `self.options_formatter`.
            caller (Object, Account or None, optional): The caller of the node.

        Returns:
            node (str): The formatted node to display.

        """

See evennia/utils/evmenu.py for the details of their default implementations.

Examples:

  • `Simple branching menu`_ - choose from options
  • `Dynamic goto`_ - jumping to different nodes based on response
  • `Set caller properties`_ - a menu that changes things
  • `Getting arbitrary input`_ - entering text
  • `Storing data between nodes`_ - keeping states and information while in the menu
  • `Repeating the same node`_ - validating within the node before moving to the next
  • `Full Menu`_: a complete example
  • `Yes/No prompt`_ - entering text with limited possible responses (this is not using EvMenu but the conceptually similar yet technically unrelated get_input helper function accessed as evennia.utils.evmenu.get_input).

Example: Simple branching menu

Below is an example of a simple branching menu node leading to different other nodes depending on choice:

# in mygame/world/mychargen.py

def define_character(caller):
    text = \
    """
    What aspect of your character do you want
    to change next?
    """
    options = ({"desc": "Change the name",
                "goto": "set_name"},
               {"desc": "Change the description",
                "goto": "set_description"})
    return text, options

EvMenu(caller, "world.mychargen", startnode="define_character")

This will result in the following node display:

What aspect of your character do you want
to change next?
_________________________
1: Change the name
2: Change the description
Note that since we didn’t specify the “name” key, EvMenu will let the user enter numbers instead. In
the following examples we will not include the EvMenu call but just show nodes running inside the
menu. Also, since EvMenu also takes a dictionary to describe the menu, we could have called it
like this instead in the example:
EvMenu(caller, {"define_character": define_character}, startnode="define_character")

Example: Dynamic goto

def _is_in_mage_guild(caller, raw_string, **kwargs):
    if caller.tags.get('mage', category="guild_member"):
        return "mage_guild_welcome"
    else:
        return "mage_guild_blocked"

def enter_guild:
    text = 'You say to the mage guard:'
    options ({'desc': 'I need to get in there.',
              'goto': _is_in_mage_guild},
             {'desc': 'Never mind',
              'goto': 'end_conversation'})
    return text, options
This simple callable goto will analyse what happens depending on who the caller is. The
enter_guild node will give you a choice of what to say to the guard. If you try to enter, you will
end up in different nodes depending on (in this example) if you have the right Tag set on
yourself or not. Note that since we don’t include any ’key’s in the option dictionary, you will just
get to pick between numbers.

Example: Set caller properties

Here is an example of passing arguments into the goto callable and use that to influence
which node it should go to next:
def _set_attribute(caller, raw_string, **kwargs):
    "Get which attribute to modify and set it"

    attrname, value = kwargs.get("attr", (None, None))
    next_node = kwargs.get("next_node")

    caller.attributes.add(attrname, attrvalue)

    return next_node


def node_background(caller):
    text = \
    """
    {} experienced a traumatic event
    in their childhood. What was it?
    """.format(caller.key}

    options = ({"key": "death",
                "desc": "A violent death in the family",
                "goto": (_set_attribute, {"attr": ("experienced_violence", True),
                      "next_node": "node_violent_background"})},
               {"key": "betrayal",
                "desc": "The betrayal of a trusted grown-up",
                "goto": (_set_attribute, {"attr": ("experienced_betrayal", True),
                      "next_node": "node_betrayal_background"})})
    return text, options

This will give the following output:

Kovash the magnificent experienced a traumatic event
in their childhood. What was it?
____________________________________________________
death: A violent death in the family
betrayal: The betrayal of a trusted grown-up
Note above how we use the _set_attribute helper function to set the attribute depending on the
User’s choice. In thie case the helper function doesn’t know anything about what node called it - we
even tell it which nodename it should return, so the choices leads to different paths in the menu.
We could also imagine the helper function analyzing what other choices

Example: Get arbitrary input

An example of the menu asking the user for input - any input.

def _set_name(caller, raw_string, **kwargs):

    inp = raw_string.strip()

    prev_entry = kwargs.get("prev_entry")

    if not inp:
        # a blank input either means OK or Abort
        if prev_entry:
            caller.key = prev_entry
            caller.msg("Set name to {}.".format(prev_entry))
            return "node_background"
        else:
        caller.msg("Aborted.")
        return "node_exit"
    else:
        # re-run old node, but pass in the name given
        return None, {"prev_entry": inp}


def enter_name(caller, raw_string, **kwargs):

    # check if we already entered a name before
    prev_entry = kwargs.get("prev_entry")

    if prev_entry:
    text = "Current name: {}.\nEnter another name or <return> to accept."
    else:
    text = "Enter your character's name or <return> to abort."

    options = {"key": "_default",
               "goto": (_set_name, {"prev_entry": prev_entry})}

    return text, options

This will display as

Enter your character's name or <return> to abort.

> Gandalf

Current name: Gandalf
Enter another name or <return> to accept.

>

Set name to Gandalf.
Here we re-use the same node twice for reading the input data from the user. Whatever we enter will
be caught by the _default option and passed into the helper function. We also pass along whatever
name we have entered before. This allows us to react correctly on an “empty” input - continue to the
node named "node_background" if we accept the input or go to an exit node if we presses Return
without entering anything. By returning None from the helper function we automatically re-run the
previous node, but updating its ingoing kwargs to tell it to display a different text.

Example: Storing data between nodes

A convenient way to store data is to store it on the caller.ndb._menutree which you can reach from
every node. The advantage of doing this is that the _menutree NAttribute will be deleted
automatically when you exit the menu.
def _set_name(caller, raw_string, **kwargs):

    caller.ndb._menutree.charactersheet = {}
    caller.ndb._menutree.charactersheet['name'] = raw_string
    caller.msg("You set your name to {}".format(raw_string)
    return "background"

def node_set_name(caller):
    text = 'Enter your name:'
    options = {'key': '_default',
               'goto': _set_name}

    return text, options

...


def node_view_sheet(caller):
    text = "Character sheet:\n {}".format(self.ndb._menutree.charactersheet)

    options = ({"key": "Accept",
                "goto": "finish_chargen"},
           {"key": "Decline",
                "goto": "start_over"})

    return text, options
Instead of passing the character sheet along from node to node through the kwargs we instead
set it up temporarily on caller.ndb._menutree.charactersheet. This makes it easy to reach from
all nodes. At the end we look at it and, if we accept the character the menu will likely save the
result to permanent storage and exit.
One point to remember though is that storage on caller.ndb._menutree is not persistent across
@reloads. If you are using a persistent menu (using EvMenu(..., persistent=True) you should use
caller.db to store in-menu data like this as well. You must then yourself make sure to clean it
when the user exits the menu.

Example: Repeating the same node

Sometimes you want to make a chain of menu nodes one after another, but you don’t want the user to
be able to continue to the next node until you have verified that what they input in the previous
node is ok. A common example is a login menu:
def _check_username(caller, raw_string, **kwargs):
    # we assume lookup_username() exists
    if not lookup_username(raw_string):
    # re-run current node by returning `None`
    caller.msg("|rUsername not found. Try again.")
    return None
    else:
    # username ok - continue to next node
    return "node_password"


def node_username(caller):
    text = "Please enter your user name."
    options = {"key": "_default",
               "goto": _check_username}
    return text, options


def _check_password(caller, raw_string, **kwargs):

    nattempts = kwargs.get("nattempts", 0)
    if nattempts > 3:
    caller.msg("Too many failed attempts. Logging out")
    return "node_abort"
    elif not validate_password(raw_string):
        caller.msg("Password error. Try again.")
    return None, {"nattempts", nattempts + 1}
    else:
    # password accepted
    return "node_login"

def node_password(caller, raw_string, **kwargs):
    text = "Enter your password."
    options = {"key": "_default",
           "goto": _check_password}
    return text, options

This will display something like

---------------------------
Please enter your username.
---------------------------

> Fo

------------------------------
Username not found. Try again.
______________________________
abort: (back to start)
------------------------------

> Foo

---------------------------
Please enter your password.
---------------------------

> Bar

--------------------------
Password error. Try again.
--------------------------

And so on.

Here the goto-callables will return to the previous node if there is an error. In the case of
password attempts, this will tick up the nattempts argument that will get passed on from iteration
to iteration until too many attempts have been made.

Defining nodes in a dictionary

You can also define your nodes directly in a dictionary to feed into the EvMenu creator.

def mynode(caller):
   # a normal menu node function
   return text, options

menu_data = {"node1": mynode,
             "node2": lambda caller: (
                      "This is the node text",
                     ({"key": "lambda node 1",
                       "desc": "go to node 1 (mynode)",
                       "goto": "node1"},
                      {"key": "lambda node 2",
                       "desc": "go to thirdnode",
                       "goto": "node3"})),
             "node3": lambda caller, raw_string: (
                       # ... etc ) }

# start menu, assuming 'caller' is available from earlier
EvMenu(caller, menu_data, startnode="node1")
The keys of the dictionary become the node identifiers. You can use any callable on the right form
to describe each node. If you use Python lambda expressions you can make nodes really on the fly.
If you do, the lambda expression must accept one or two arguments and always return a tuple with two
elements (the text of the node and its options), same as any menu node function.
Creating menus like this is one way to present a menu that changes with the circumstances - you
could for example remove or add nodes before launching the menu depending on some criteria. The
drawback is that a lambda expression `is much more limited`_ than a full
function - for example you can’t use other Python keywords like if inside the body of the
lambda.
Unless you are dealing with a relatively simple dynamic menu, defining menus with lambda’s is
probably more work than it’s worth: You can create dynamic menus by instead making each node
function more clever. See the `NPC shop tutorial`_ for an example of this.

Ask for simple input

This describes two ways for asking for simple questions from the user. Using Python’s raw_string
will not work in Evennia. raw_string will block the entire server for everyone until that one
player has entered their text, which is not what you want.

The yield way

In the func method of your Commands (only) you can use Python’s built-in yield command to
request input in a similar way to raw_string. It looks like this:
result = yield("Please enter your answer:")
This will send “Please enter your answer” to the Command’s self.caller and then pause at that
point. All other players at the server will be unaffected. Once caller enteres a reply, the code
execution will continue and you can do stuff with the result. Here is an example:
from evennia import Command
class CmdTestInput(Command):
    key = "test"
    def func(self):
        result = yield("Please enter something:")
        self.caller.msg(f"You entered {result}.")
        result2 = yield("Now enter something else:")
        self.caller.msg(f"You now entered {result2}.")
Using yield is simple and intuitive, but it will only access input from self.caller and you
cannot abort or time out the pause until the player has responded. Under the hood, it is actually
just a wrapper calling get_input described in the following section.
Important Note: In Python you cannot mix ``yield`` and ``return <value>`` in the same method. It has
to do with yield turning the method into a
`generator`_. A return without an argument works, you
can just not do return <value>. This is usually not something you need to do in func() anyway,
but worth keeping in mind.

The get_input way

The evmenu module offers a helper function named get_input. This is wrapped by the yield
statement which is often easier and more intuitive to use. But get_input offers more flexibility
and power if you need it. While in the same module as EvMenu, get_input is technically unrelated
to it. The get_input allows you to ask and receive simple one-line input from the user without
launching the full power of a menu to do so. To use, call get_input like this:
get_input(caller, prompt, callback)
Here caller is the entity that should receive the prompt for input given as prompt. The
callback is a callable function(caller, prompt, user_input) that you define to handle the answer
from the user. When run, the caller will see prompt appear on their screens and any text they
enter will be sent into the callback for whatever processing you want.

Below is a fully explained callback and example call:

from evennia import Command
from evennia.utils.evmenu import get_input

def callback(caller, prompt, user_input):
    """
    This is a callback you define yourself.

    Args:
        caller (Account or Object): The one being asked
          for input
        prompt (str): A copy of the current prompt
        user_input (str): The input from the account.

    Returns:
        repeat (bool): If not set or False, exit the
          input prompt and clean up. If returning anything
          True, stay in the prompt, which means this callback
          will be called again with the next user input.
    """
    caller.msg(f"When asked '{prompt}', you answered '{user_input}'.")

get_input(caller, "Write something! ", callback)

This will show as

Write something!
> Hello
When asked 'Write something!', you answered 'Hello'.
Normally, the get_input function quits after any input, but as seen in the example docs, you could
return True from the callback to repeat the prompt until you pass whatever check you want.
Note: You cannot link consecutive questions by putting a new get_input call inside the
callback If you want that you should use an EvMenu instead (see the Repeating the same node example above). Otherwise you can either peek at the
implementation of get_input and implement your own mechanism (it’s just using cmdset nesting) or

Example: Yes/No prompt

Below is an example of a Yes/No prompt using the get_input function:

def yesno(caller, prompt, result):
    if result.lower() in ("y", "yes", "n", "no"):
        # do stuff to handle the yes/no answer
        # ...
        # if we return None/False the prompt state
        # will quit after this
    else:
        # the answer is not on the right yes/no form
        caller.msg("Please answer Yes or No. \n{prompt}")
@        # returning True will make sure the prompt state is not exited
        return True

# ask the question
get_input(caller, "Is Evennia great (Yes/No)?", yesno)

The @list_node decorator

The evennia.utils.evmenu.list_node is an advanced decorator for use with EvMenu node functions.
It is used to quickly create menus for manipulating large numbers of items.
text here
______________________________________________

1. option1     7. option7      13. option13
2. option2     8. option8      14. option14
3. option3     9. option9      [p]revius page
4. option4    10. option10      page 2
5. option5    11. option11     [n]ext page
6. option6    12. option12
The menu will automatically create an multi-page option listing that one can flip through. One can
inpect each entry and then select them with prev/next. This is how it is used:
from evennia.utils.evmenu import list_node


...

_options(caller):
    return ['option1', 'option2', ... 'option100']

_select(caller, menuchoice, available_choices):
    # analyze choice
    return "next_node"

@list_node(options, select=_select, pagesize=10)
def node_mylist(caller, raw_string, **kwargs):
    ...

    return text, options
The options argument to list_node is either a list, a generator or a callable returning a list
of strings for each option that should be displayed in the node.
The select is a callable in the example above but could also be the name of a menu node. If a
callable, the menuchoice argument holds the selection done and available_choices holds all the
options available. The callable should return the menu to go to depending on the selection (or
None to rerun the same node). If the name of a menu node, the selection will be passed as
selection kwarg to that node.
The decorated node itself should return text to display in the node. It must return at least an
empty dictionary for its options. It returning options, those will supplement the options
auto-created by the list_node decorator.

Assorted notes

The EvMenu is implemented using `Commands`_. When you start a new EvMenu, the user of the
menu will be assigned a CmdSet with the commands they need to navigate the menu.
This means that if you were to, from inside the menu, assign a new command set to the caller, you may override the Menu Cmdset and kill the menu. If you want to assign cmdsets to the caller as part
of the menu, you should store the cmdset on caller.ndb._menutree and wait to actually assign it
until the exit node.

limited: https://docs.python.org/2/tutorial/controlflow.html#lambda-expressions .. _NPC shop tutorial: NPC-shop-Tutorial.html .. _generator: https://www.learnpython.org/en/Generators .. _Repeating the same node: EvMenu#example-repeating-the-same-node .. _this extension suggested on the mailing list: https://groups.google.com/forum/#!category-topic/evennia/evennia-questions/16pi0SfMO5U .. _Commands: Commands.html