Developer Plugin Documentation

Plugins allow you to customise and extend the behavior of EDMC.

Installing a Plugin

See Plugins on the wiki.

Writing a Plugin

Plugins are loaded when EDMC starts up.

Each plugin has it's own folder in the plugins directory:

Windows: %LOCALAPPDATA%\EDMarketConnector\plugins
Mac: ~/Library/Application Support/EDMarketConnector/plugins
Linux: $XDG_DATA_HOME/EDMarketConnector/plugins, or ~/.local/share/EDMarketConnector/plugins if $XDG_DATA_HOME is unset.

Plugins are python files. The plugin folder must have a file named load.py that must provide one module level function and optionally provide a few others.

If you're running from source (which allows for debugging with e.g. PyCharm) then you'll need to be using an appropriate version of Python. The current version is listed in the Environment section of Releasing.md. If you're developing your plugin simply against an install of EDMarketConnector then you'll be relying on the bundled version of Python (it's baked into the .exe via the py2exe build process).

Examples

We have some example plugins available in the docs/examples directory. See the readme in each folder for more info.

Available imports

importing anything from the core EDMarketConnector code that is not explicitly mentioned here is unsupported and may lead to your plugin breaking with future code changes.

import L10n - for plugin localisation support.

from theme import theme - So plugins can theme their own UI elements to match the main UI.

from config import appname, applongname, appcmdname, appversion , copyright, config - to access config.

from prefs import prefsVersion - to allow for versioned preferences.

from companion import category_map - Or any of the other static date contained therein. NB: There's a plan to move such to a data module.

import plug - Mostly for using plug.show_error(). Also the flags for dashboard_entry() to be useful (see example below). Relying on anything else isn't supported.

from monitor import game_running - in case a plugin needs to know if we think the game is running. NB: This is a function, and should be called as such. Using the bare word game_running will always be True.

import timeout_session - provides a method called new_session that creates a requests.session with a default timeout on all requests. Recommended to reduce noise in HTTP requests

from ttkHyperlinkLabel import HyperlinkLabel
import myNotebook as nb

For creating UI elements.

Logging

In the past the only way to provide any logged output from a plugin was to use print(...) statements. When running the application from the packaged executeable all output is redirected to a log file. See Reporting a problem for the location of this log file.

EDMC now implements proper logging using the Python logging module. Plugin developers should now use the following code instead of simple print(...) statements.

Insert this at the top-level of your load.py file (so not inside plugin_start3() ):

import logging

from config import appname

# This could also be returned from plugin_start3()
plugin_name = os.path.basename(os.path.dirname(__file__))

# A Logger is used per 'found' plugin to make it easy to include the plugin's
# folder name in the logging output format.
# NB: plugin_name here *must* be the plugin's folder name as per the preceding
#     code, else the logger won't be properly set up.
logger = logging.getLogger(f'{appname}.{plugin_name}')

# If the Logger has handlers then it was already set up by the core code, else
# it needs setting up here.
if not logger.hasHandlers():
    level = logging.INFO  # So logger.info(...) is equivalent to print()

    logger.setLevel(level)
    logger_channel = logging.StreamHandler()
    logger_formatter = logging.Formatter(f'%(asctime)s - %(name)s - %(levelname)s - %(module)s:%(lineno)d:%(funcName)s: %(message)s')
    logger_formatter.default_time_format = '%Y-%m-%d %H:%M:%S'
    logger_formatter.default_msec_format = '%s.%03d'
    logger_channel.setFormatter(logger_formatter)
    logger.addHandler(logger_channel)

Note the admonishment about plugin_name being the folder name of your plugin. It can't be anything else (such as a different string returned from plugin_start3()) because the code in plug.py that sets up the logger uses exactly the folder name. Our custom qualname and class formatters won't work with a 'bare' logger, and will cause your code to throw exceptions if you're not using our supplied logger.

If running with 4.1.0-beta1 or later of EDMC the logging setup happens in the core code and will include the extra logfile destinations. If your plugin is run under a pre-4.1.0 version of EDMC then the above will set up basic logging only to the console (and thus redirected to the log file).

If you're certain your plugin will only be run under EDMC 4.1.0 or newer then you can remove the if clause.

Replace all print(...) statements with one of the following:

    logger.info('some info message')  # instead of print(...)

    logger.debug('something only for debug')

    logger.warning('Something needs warning about')

    logger.error('Some error happened')

    logger.critical('Something went wrong in a critical manner')

    try:
        ...
    except Exception:
        # This logs at 'ERROR' level.
        # Also automatically includes exception information.
        logger.exception('An exception occurred')

    try:
        ...
    except Exception as e:
        logger.debug('Exception we only note in debug output', exc_info=e)

Remember you can use fstrings to include variables, and even the returns of functions, in the output.

    logger.debug(f"Couldn't frob the {thing} with the {wotsit()}")

Startup

EDMC will import the load.py file as a module and then call the plugin_start3() function.

def plugin_start3(plugin_dir: str) -> str:
   """
   Load this plugin into EDMC
   """
   print(f"I am loaded! My plugin folder is {plugin_dir}")
   return "Test"

The string you return is used as the internal name of the plugin.

Any errors or print statements from your plugin will appear in %TMP%\EDMarketConnector.log on Windows, $TMPDIR/EDMarketConnector.log on Mac, and $TMP/EDMarketConnector.log on Linux.

Parameter	Type	Description
`plugin_dir`	`str`	The directory that your plugin is located in.
`RETURN`	`str`	The name you want to be used for your plugin internally

Shutdown

This gets called when the user closes the program:

def plugin_stop() -> None:
    """
    EDMC is closing
    """
    print("Farewell cruel world!")

If your plugin uses one or more threads to handle Events then stop() and join() (to wait for their exit -- Recommended, not required) the threads before returning from this function.

Plugin Hooks

Configuration

If you want your plugin to be configurable via the GUI you can define a frame (panel) to be displayed on its own tab in EDMC's settings dialog. The tab title will be the value that you returned from plugin_start3. Use widgets from EDMC's myNotebook.py for the correct look-and-feel. You can be notified when the settings dialog is closed so you can save your settings.

You can use set(), get() and getint() from EDMC's config.config object to retrieve your plugin's settings in a platform-independent way.

Be sure to use a unique prefix for any settings you save so as not to clash with core EDMC or other plugins.

Use numberFromString() from EDMC's l10n.Locale object to parse input numbers in a locale-independent way.

Note that in the following example the function signature defines that it returns Optional[tk.Frame] only because we need to allow for None if something goes wrong with the creation of the frame (the calling code checks this). You absolutely need to return the nb.Frame() instance that you get as in the code below.

import tkinter as tk
from tkinter import ttk
import myNotebook as nb
from config import config
from typing import Optional

my_setting: Optional[tk.IntVar] = None

def plugin_prefs(parent: nb.Notebook, cmdr: str, is_beta: bool) -> Optional[tk.Frame]:
   """
   Return a TK Frame for adding to the EDMC settings dialog.
   """
   global my_setting
   my_setting = tk.IntVar(value=config.getint("MyPluginSetting"))  # Retrieve saved value from config
   frame = nb.Frame(parent)
   nb.Label(frame, text="Hello").grid()
   nb.Label(frame, text="Commander").grid()
   nb.Checkbutton(frame, text="My Setting", variable=my_setting).grid()

   return frame

Parameter	Type	Description
`parent`	`nb.Notebook`	Root Notebook object the preferences window uses
`cmdr`	`str`	The current commander
`is_beta`	`bool`	If the game is currently a beta version

This gets called when the user dismisses the settings dialog:

def prefs_changed(cmdr: str, is_beta: bool) -> None:
   """
   Save settings.
   """
   config.set('MyPluginSetting', my_setting.get())  # Store new value in config

Parameter	Type	Description
`cmdr`	`str`	The current commander
`is_beta`	`bool`	If the game is currently a beta version

Display

You can also have your plugin add an item to the EDMC main window and update from your event hooks. This works in the same way as plugin_prefs(). For a simple one-line item return a tk.Label widget or a 2 tuple of widgets. For a more complicated item create a tk.Frame widget and populate it with other ttk widgets. Return None if you just want to use this as a callback after the main window and all other plugins are initialised.

You can use stringFromNumber() from EDMC's l10n.Locale object to format numbers in your widgets in a locale-independent way.

from typing import Optional, Tuple
import tkinter as tk

status: Optional[tk.Label]


def plugin_app(parent: tk.Frame) -> Tuple[tk.Label, tk.Label]:
    """
    Create a pair of TK widgets for the EDMC main window
    """
    global status
    label = tk.Label(parent, text="Status:")  # By default widgets inherit the current theme's colors
    status = tk.Label(parent, text="", foreground="yellow")  # Override theme's foreground color
    return (label, status)

# later on your event functions can update the contents of these widgets
def some_other_function() -> None:
    global status
    status["text"] = "Happy!"
    status["foreground"] = "green"

Parameter	Type	Description
`parent`	`tk.Frame`	The root EDMC window
`RETURN`	`Union[tk.Widget, Tuple[tk.Widget, tk.Widget]]`	A widget to add to the main window. See below for more info

The return from plugin_app can either be any widget (Frame, Label, Notebook, etc.), or a 2 tuple of widgets. In the case of a 2 tuple, indices 0 and 1 are placed automatically in the outer grid on column indices 0 and 1. Otherwise, the only thing done to your return widget is it is set to use a columnspan of 2, and placed on the grid.

You can dynamically add and remove widgets on the main window by returning a tk.Frame from plugin_app() and later creating and destroying child widgets of that frame.

from typing import Option
import tkinter as tk

from theme import theme

frame: Optional[tk.Frame] = None

def plugin_app(parent: tk.Frame) -> tk.Frame:
    """
    Create a frame for the EDMC main window
    """
    global frame
    frame = tk.Frame(parent)
    return frame

def some_other_function_called_later() -> None:
# later on your event functions can add or remove widgets
    row = frame.grid_size()[1]
    new_widget_1 = tk.Label(frame, text="Status:")
    new_widget_1.grid(row=row, column=0, sticky=tk.W)
    new_widget_2 = tk.Label(frame, text="Unhappy!", foreground="red")  # Override theme's foreground color
    new_widget_2.grid(row=row, column=1, sticky=tk.W)
    theme.update(this.frame)  # Apply theme colours to the frame and its children, including the new widgets

Events

Once you have created your plugin and EDMC has loaded it there are three other functions you can define to be notified by EDMC when something happens: journal_entry(), dashboard_entry() and cmdr_data().

Your events all get called on the main Tkinter loop so be sure not to block for very long or the app will appear to freeze. If you have a long running operation such as sending or receiving data from an external server then you should do this in a separate worker Thread. You can send work items to the worker thread over a Queue. Tkinter is not thread-safe so you should not access any Tkinter resources (including widgets and variables) from worker threads - doing so may cause the app to crash intermittently. You can signal back to the main thread using Tkinter's event_generate() widget method, generating a user-defined event that you have previously registered with the bind_all() widget method. See the EDSM plugin for an example of these techniques.

Journal Entry

def journal_entry(
    cmdr: str, is_beta: bool, system: str, station: str, entry: Dict[str, Any], state: Dict[str, Any]
) -> None:
    if entry['event'] == 'FSDJump':
        # We arrived at a new system!
        if 'StarPos' in entry:
            logger.info(f'Arrived at {entry["StarSystem"]} {entry["StarPos"]}')

        else:
            logger.info(f'Arrived at {entry["StarSystem"]}')

This gets called when EDMC sees a new entry in the game's journal.

Parameter	Type	Description
`cmdr`	`str`	Current commander name
`is_beta`	`bool`	Is the game currently in beta
`system`	`Optional[str]`	Current system, if known
`station`	`Optional[str]`	Current station, if any
`entry`	`Dict[str, Any]`	The journal event
`state`	`Dict[str, Any]`	More info about the commander, their ship, and their cargo (see below)

Content of state (updated to the current journal entry):

Field	Type	Description
`Captain`	`Optional[str]`	Name of the commander who's crew you're on, if any
`Cargo`	`dict`	Current cargo. Note that this will be totals, and any mission specific duplicates will be counted together
`CargoJSON`	`dict`	content of cargo.json as of last read.
`Credits`	`int`	Current credits balance
`FID`	`str`	Frontier commander ID
`Loan`	`Optional[int]`	Current loan amount, if any
`Raw`	`dict`	Current raw engineering materials
`Manufactured`	`dict`	Current manufactured engineering materials
`Encoded`	`dict`	Current encoded engineering materials
`Engineers`	`dict`	Current Raw engineering materials
`Rank`	`Dict[str, Tuple[int, int]`	Current ranks, each entry is a tuple of the current rank, and age
`Statistics`	`dict`	Contents of a Journal Statistics event, ie, data shown in the stats panel. See the Journal manual for more info
`Role`	`Optional[str]`	Current role if in multi-crew, one of `Idle`, `FireCon`, `FighterCon`
`Friends`	`set`	Currently online friend
`ShipID`	`int`	Frontier ID of current ship
`ShipIdent`	`str`	Current user-set ship ID
`ShipName`	`str`	Current user-set ship name
`ShipType`	`str`	Internal name for the current ship type
`HullValue`	`int`	Current ship value, excluding modules
`ModulesValue`	`int`	Value of the current ship's modules
`Rebuy`	`int`	Current ship's rebuy cost
`Modules`	`dict`	Currently fitted modules

A special "StartUp" entry is sent if EDMC is started while the game is already running. In this case you won't receive initial events such as "LoadGame", "Rank", "Location", etc. However the state dictionary will reflect the cumulative effect of these missed events.

Similarly, a special "ShutDown" entry is sent when the game stops writing to the Journal without writing a "Shutdown" event. This might happen, for example, when the game client crashes. Note that this is distinct in (letter) case from the "Shutdown" event that the game itself writes to the Journal when you exit normally. If you want to react to either in your plugin code then either compare in a case insensitive manner or check for both. The difference in case allows you to differentiate between the two scenarios.

This event is not sent when EDMC is running on a different machine so you should not rely on receiving this event.

Player Dashboard

import plug

def dashboard_entry(cmdr: str, is_beta: bool, entry: Dict[str, Any]):
    is_deployed = entry['Flags'] & plug.FlagsHardpointsDeployed
    sys.stderr.write("Hardpoints {}\n".format(is_deployed and "deployed" or "stowed"))

This gets called when something on the player's cockpit display changes - typically about once a second when in orbital flight.

Parameter	Type	Description
`cmdr`	`str`	Current command name
`is_beta`	`bool`	if the game is currently in beta
`entry`	`dict`	Data from status.json (see below)

For more info on status.json, See the "Status File" section in the Frontier Journal documentation for the available entry properties and for the list of available "Flags". Refer to the source code of plug.py for the list of available constants.

New in version 4.1.6:

CargoJSON contains the raw data from the last read of Cargo.json passed through json.load. It contains more information about the cargo contents, such as the mission ID for mission specific cargo

NB: Because this is only the data loaded from the Cargo.json file, and that is not written at Commander login (instead the in-Journal Cargo event contains all the data), this will not be populated at login.

Getting Commander Data

def cmdr_data(data, is_beta):
    """
    We have new data on our commander
    """
    if data.get('commander') is None or data['commander'].get('name') is None:
        raise ValueError("this isn't possible")

    logger.info(data['commander']['name'])

This gets called when EDMC has just fetched fresh Cmdr and station data from Frontier's servers.

Parameter	Type	Description
`data`	`Dict[str, Any]`	`/profile` API response, with `/market` and `/shipyard` added under the keys `marketdata` and `shipdata`
`is_beta`	`bool`	If the game is currently in beta

Plugin-specific events

def edsm_notify_system(reply):
    """
    `reply` holds the response from a call to https://www.edsm.net/en/api-journal-v1
    """
    if not reply:
        logger.info("Error: Can't connect to EDSM")

    elif reply['msgnum'] // 100 not in (1,4):
        logger.info(f'Error: EDSM {reply["msg"]}')

    elif reply.get('systemCreated'):
        logger.info('New EDSM system!')

    else:
        logger.info('Known EDSM system')

If the player has chosen to "Send flight log and Cmdr status to EDSM" this gets called when the player starts the game or enters a new system. It is called some time after the corresponding journal_entry() event.

Parameter	Type	Description
`reply`	`Dict[str, Any]`	Response to an API call to EDSM's journal API target

def inara_notify_location(event_data):
    """
    `event_data` holds the response to one of the "Commander's Flight Log" events https://inara.cz/inara-api-docs/#event-29
    """
    if event_data.get('starsystemInaraID'):
        logging.info(f'Now in Inara system {event_data["starsystemInaraID"]} at {event_data["starsystemInaraURL"]}')
    else:
        logger.info('System not known to Inara')

    if event_data.get('stationInaraID'):
        logger.info(f'Docked at Inara station {event_data["stationInaraID"]} at {event_data["stationInaraURL"]}')

    else:
        logger.info('Undocked or station unknown to Inara')

If the player has chosen to "Send flight log and Cmdr status to Inara" this gets called when the player starts the game, enters a new system, docks or undocks. It is called some time after the corresponding journal_entry() event.

Parameter	Type	Description
`event_data`	`Dict[str, Any]`	Response to an API call to INARA's `Commander Flight Log` event

def inara_notify_ship(event_data):
    """
    `event_data` holds the response to an addCommanderShip or setCommanderShip event https://inara.cz/inara-api-docs/#event-11
    """
    if event_data.get('shipInaraID'):
        logger.info(
            f'Now in Inara ship {event_data['shipInaraID'],} at {event_data['shipInaraURL']}
        )

If the player has chosen to "Send flight log and Cmdr status to Inara" this gets called when the player starts the game or switches ship. It is called some time after the corresponding journal_entry() event.

Parameter	Type	Description
`event_data`	`Dict[str, Any]`	Response to an API call to INARA's `addCommanderShip` or `setCommanderShip` event

Error messages

You can display an error in EDMC's status area by returning a string from your journal_entry(), dashboard_entry() or cmdr_data() function, or asynchronously (e.g. from a "worker" thread that is performing a long running operation) by calling plug.show_error(). Either method will cause the "bad" sound to be played (unless the user has muted sound).

The status area is shared between EDMC itself and all other plugins, so your message won't be displayed for very long. Create a dedicated widget if you need to display routine status information.

Localisation

You can localise your plugin to one of the languages that EDMC itself supports. Add the following boilerplate near the top of each source file that contains strings that needs translating:

import l10n
import functools
_ = functools.partial(l10n.Translations.translate, context=__file__)

Wrap each string that needs translating with the _() function, e.g.:

    status["text"] = _('Happy!')  # Main window status

If you display localized strings in EDMC's main window you should refresh them in your prefs_changed function in case the user has changed their preferred language.

Translation files should reside in folder named L10n inside your plugin's folder. Files must be in macOS/iOS ".strings" format, encoded as UTF-8. You can generate a starting template file for your translations by invoking l10n.py in your plugin's folder. This extracts all the translatable strings from Python files in your plugin's folder and places them in a file named en.template in the L10n folder. Rename this file as <language_code>.strings and edit it.

See EDMC's own L10n folder for the list of supported language codes and for example translation files.

Python Package Plugins

A Package Plugin is both a standard Python package (i.e. contains an __init__.py file) and an EDMC plugin (i.e. contains a load.py file providing at minimum a plugin_start3() function). These plugins are loaded before any non-Package plugins.

Other plugins can access features in a Package Plugin by importing the package by name in the usual way.

Distributing a Plugin

To package your plugin for distribution simply create a .zip archive of your plugin's folder:

Windows: In Explorer right click on your plugin's folder and choose Send to → Compressed (zipped) folder.
Mac: In Finder right click on your plugin's folder and choose Compress.

If there are any external dependencies then include them in the plugin's folder.

Optionally, for tidiness delete any .pyc and .pyo files in the archive, as well as the __pycache__ directory.

Disable a plugin

EDMC now lets you disable a plugin without deleting it, simply rename the plugin folder to append ".disabled". Eg, "SuperSpaceHelper" -> "SuperSpaceHelper.disabled"

Disabled and enabled plugins are listed on the "Plugins" Settings tab

Migration

Starting with pre-release 3.5 EDMC uses Python 3.7. The first full release under Python 3.7 was 4.0.0.0. This is a brief outline of the steps required to migrate a plugin from earlier versions of EDMC:

Rename the function plugin_start to plugin_start3(plugin_dir). Plugins without a plugin_start3 function are listed as disabled on EDMC's "Plugins" tab and a message like "plugin SuperSpaceHelper needs migrating" appears in the log. Such plugins are also listed in a section "Plugins Without Python 3.x Support:" on the Settings > Plugins tab.
Check that callback functions plugin_prefs, prefs_changed, journal_entry, dashboard_entry and cmdr_data if used are declared with the correct number of arguments. Older versions of this app were tolerant of missing arguments in these function declarations.
Port the code to Python 3.7. The 2to3 tool can automate much of this work.

Depending on the complexity of the plugin it may be feasible to make it compatible with both EDMC 3.4 + Python 2.7 and EDMC 3.5 + Python 3.7.

Here's a guide on writing Python 2/3 compatible code and here's an example of the changes required for a simple plugin.

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PLUGINS.md

PLUGINS.md

Developer Plugin Documentation

Installing a Plugin

Writing a Plugin

Examples

Available imports

Logging

Startup

Shutdown

Plugin Hooks

Configuration

Display

Events

Journal Entry

Player Dashboard

Getting Commander Data

Plugin-specific events

Error messages

Localisation

Python Package Plugins

Distributing a Plugin

Disable a plugin

Migration

Files

PLUGINS.md

Latest commit

History

PLUGINS.md

File metadata and controls

Developer Plugin Documentation

Installing a Plugin

Writing a Plugin

Examples

Available imports

Logging

Startup

Shutdown

Plugin Hooks

Configuration

Display

Events

Journal Entry

Player Dashboard

Getting Commander Data

Plugin-specific events

Error messages

Localisation

Python Package Plugins

Distributing a Plugin

Disable a plugin

Migration