# Inputfuncs

```
          Internet│
            ┌─────┐ │                                   ┌────────┐
┌──────┐    │Text │ │  ┌────────────┐    ┌─────────┐    │Command │
│Client├────┤JSON ├─┼──►commandtuple├────►Inputfunc├────►DB query│
└──────┘    │etc  │ │  └────────────┘    └─────────┘    │etc     │
            └─────┘ │                                   └────────┘
                    │Evennia

```

The Inputfunc is the last fixed step on the [Ingoing message path](../Concepts/Messagepath.md#ingoing-message-path). The available Inputfuncs are looked up and called using `commandtuple` structures sent from the client. The job of the Inputfunc is to perform whatever action is requested, by firing a Command, performing a database query or whatever is needed.

Given a `commandtuple` on the form 

    (commandname, (args), {kwargs})

Evennia will try to find and call an Inputfunc on the form 

```python
def commandname(session, *args, **kwargs):
    # ...

```
Or, if no match was found, it will call an inputfunc named "default" on this form

```python
def default(session, cmdname, *args, **kwargs):
    # cmdname is the name of the mismatched inputcommand

```

The default inputfuncs are found in [evennia/server/inputfuncs.py](evennia.server.inputfuncs). 

## Adding your own inputfuncs

1. Add a function on the above form to `mygame/server/conf/inputfuncs.py`. Your function must be in the global, outermost scope of that module and not start with an underscore (`_`) to be recognized as an inputfunc.  i
2. `reload` the server. 

To overload a default inputfunc (see below), just add a function with the same name. You can also extend the settings-list `INPUT_FUNC_MODULES`.

    INPUT_FUNC_MODULES += ["path.to.my.inputfunc.module"]

All global-level functions with a name not starting with `_` in these module(s) will be used by Evennia as an inputfunc. The list is imported from left to right, so latter imported functions will replace earlier ones.

## Default inputfuncs

Evennia defines a few default inputfuncs to handle the common cases. These are defined in
`evennia/server/inputfuncs.py`.

### text

 - Input: `("text", (textstring,), {})`
 - Output: Depends on Command triggered

This is the most common of inputs, and the only one supported by every traditional mud. The argument is usually what the user sent from their command line. Since all text input from the user
like this is considered a [Command](./Commands.md), this inputfunc will do things like nick-replacement and then pass on the input to the central Commandhandler.

### echo

 - Input: `("echo", (args), {})`
 - Output: `("text", ("Echo returns: %s" % args), {})`

This is a test input, which just echoes the argument back to the session as text. Can be used for testing custom client input.

### default

The default function, as mentioned above, absorbs all non-recognized inputcommands. The default one will just log an error.

### client_options

 - Input: `("client_options, (), {key:value, ...})`
 - Output:
  - normal: None
  - get: `("client_options", (), {key:value, ...})`

This is a direct command for setting protocol options. These are settable with the `@option`
command, but this offers a client-side way to set them. Not all connection protocols makes use of
all flags, but here are the possible keywords:

 - get (bool): If this is true, ignore all other kwargs and immediately return the current settings
as an outputcommand `("client_options", (), {key=value, ...})`-
 - client (str): A client identifier, like "mushclient".
 - version (str): A client version
 - ansi (bool): Supports ansi colors
 - xterm256 (bool): Supports xterm256 colors or not
 - mxp (bool): Supports MXP or not
 - utf-8 (bool): Supports UTF-8 or not
 - screenreader (bool): Screen-reader mode on/off
 - mccp (bool): MCCP compression on/off
 - screenheight (int): Screen height in lines
 - screenwidth (int): Screen width in characters
 - inputdebug (bool): Debug input functions
 - nomarkup (bool): Strip all text tags
 - raw (bool): Leave text tags unparsed 

> Note that there are two GMCP aliases to this inputfunc - `hello` and `supports_set`, which means it will be accessed via the GMCP `Hello` and `Supports.Set` instructions assumed by some clients.

### get_client_options

 - Input: `("get_client_options, (), {key:value, ...})`
 - Output: `("client_options, (), {key:value, ...})`

This is a convenience wrapper that retrieves the current options by sending "get" to `client_options` above.

### get_inputfuncs

- Input: `("get_inputfuncs", (), {})`
- Output: `("get_inputfuncs", (), {funcname:docstring, ...})`
 
Returns an outputcommand on the form `("get_inputfuncs", (), {funcname:docstring, ...})` - a list of all the available inputfunctions along with their docstrings. 

### login

> Note: this is currently experimental and not very well tested.

 - Input: `("login", (username, password), {})`
 - Output: Depends on login hooks

This performs the inputfunc version of a login operation on the current Session. It's meant to be used by custom client setups.

### get_value

Input: `("get_value", (name, ), {})`
Output: `("get_value", (value, ), {})`

Retrieves a value from the Character or Account currently controlled by this Session. Takes one argument, This will only accept particular white-listed names, you'll need to overload the function to expand. By default the following values can be retrieved:  

 - "name" or "key": The key of the Account or puppeted Character.
 - "location": Name of the current location, or "None".
 - "servername": Name of the Evennia server connected to.

### repeat 

 - Input: `("repeat", (), {"callback":funcname,  "interval": secs, "stop": False})` 
 - Output: Depends on the repeated function. Will return `("text", (repeatlist),{}` with a list of
accepted names if given an unfamiliar callback name.

This will tell evennia to repeatedly call a named function at a given interval. Behind the scenes this will set up a [Ticker](./TickerHandler.md). Only previously acceptable functions are possible to repeat-call in this way, you'll need to overload this inputfunc to add the ones you want to offer. By default only two example functions are allowed, "test1" and "test2", which will just echo a text back at the given interval. Stop the repeat by sending `"stop": True` (note that you must include both the callback name and interval for Evennia to know what to stop).

### unrepeat

 - Input: `("unrepeat", (), ("callback":funcname, 
                             "interval": secs)`
 - Output: None

This is a convenience wrapper for sending "stop" to the `repeat` inputfunc. 

### monitor

 - Input: `("monitor", (), ("name":field_or_argname, stop=False)`
 - Output (on change): `("monitor", (), {"name":name, "value":value})`

This sets up on-object monitoring of Attributes or database fields. Whenever the field or Attribute changes in any way, the outputcommand will be sent. This is using the [MonitorHandler](./MonitorHandler.md) behind the scenes. Pass the "stop" key to stop monitoring. Note that you must supply the name also when stopping to let the system know which monitor should be cancelled.

Only fields/attributes in a whitelist are allowed to be used, you have to overload this function to add more. By default the following fields/attributes can be monitored:

 - "name": The current character name 
 - "location": The current location
 - "desc": The description Argument

### unmonitor

 - Input: `("unmonitor", (), {"name":name})`
 - Output: None

A convenience wrapper that sends "stop" to the `monitor` function. 