Plugins

The application allows you to create and add plugins, hooking on certain events triggered.

Configuration

You can create plugins in their own file in dsmr_plugins/modules/plugin_name.py, where plugin_name is the name of your plugin.

Please make sure the plugin_name,

  • is lowercase (plugin_name and not PLUGIN_NAME),
  • does not contains spaces or dashes, only use underscores and do not start the name with a digit.

See also

Add the dotted path as DSMRREADER_PLUGINS env var. For more information see DSMRREADER_PLUGINS in Env Settings.

Your plugin file is imported once, so you should make sure to hook any events you want.

And finally, make sure to reload the application by deploying it again. You can do that by simply executing the post-deploy.sh script in the root of the project.

Events / Signals

These are either dispatched by the Django framework or the application at some point.

dsmr_backend.signals.backend_called

Called by each iteration of the backend. Please use with caution, as it may block all backend operations when used improperly.

dsmr_pvoutput.signals.pvoutput_upload

Called by dsmr_pvoutput just before uploading data to PVOutput. The data kwarg contains the data to be sent.

dsmr_datalogger.signals.raw_telegram

Called by dsmr_datalogger when receiving or reading a telegram string. The data kwarg contains the raw telegram string.

dsmr_notification.signals.notification_sent

Called by dsmr_notification just after dispatching a notification. The title kwarg contains the notification title, message contains the message body.

django.db.models.signals.post_save

Called by Django after saving new records to the database. Can be bound to the DayStatistics model for example, to process daily statistics elsewhere.

Other

More signals may be available for use, please be careful when binding Django save-signals as it may impact performance.

Examples:

Example #1: Upload data to second PVOutput account

This is an example of issue #407, requesting the feature to upload data to a second PVOuput account.

See also

DSMRREADER_PLUGINS configuration:

DSMRREADER_PLUGINS=dsmr_plugins.modules.secondary_pvoutput_upload

Plugin file dsmr_plugins/modules/secondary_pvoutput_upload.py (new file):

import requests

from django.dispatch import receiver

from dsmr_pvoutput.models.settings import PVOutputAddStatusSettings
from dsmr_pvoutput.signals import pvoutput_upload


@receiver(pvoutput_upload)
def handle_secondary_pvoutput_upload(**kwargs):
    print(' - Uploading the same data to PVOutput using plugin: {}'.format(kwargs['data']))

    response = requests.post(
        PVOutputAddStatusSettings.API_URL,
        headers={
            'X-Pvoutput-Apikey': 'XXXXX',
            'X-Pvoutput-SystemId': 'YYYYY',
        },
        data=kwargs['data']
    )

    if response.status_code != 200:
        print(' [!] PVOutput upload failed (HTTP {}): {}'.format(response.status_code, response.text))

Attention

Note that the XXXXX and YYYYY variables should be replace by your second set of PVOutput API credentials.

Example #2: Forwarding raw telegram data to another serial port

This is an example of issue #557, allowing raw DSMR telegrams to be forwarded to another serial port.

See also

DSMRREADER_PLUGINS configuration:

DSMRREADER_PLUGINS=dsmr_plugins.modules.forward_raw_telegram_to_serial

Plugin file dsmr_plugins/modules/forward_raw_telegram_to_serial.py (new file):

import serial

from django.dispatch import receiver

from dsmr_datalogger.signals import raw_telegram
import dsmr_datalogger.services.datalogger


@receiver(raw_telegram)
def handle_forward_raw_telegram_to_serial(**kwargs):
    DEST_PORT = '/dev/ttyUSBvA'
    connection_parameters = dsmr_datalogger.services.datalogger.get_dsmr_connection_parameters()

    serial_handle = serial.Serial()
    serial_handle.port = DEST_PORT
    serial_handle.baudrate = connection_parameters['baudrate']
    serial_handle.bytesize = connection_parameters['bytesize']
    serial_handle.parity = connection_parameters['parity']
    serial_handle.stopbits = serial.STOPBITS_ONE
    serial_handle.xonxoff = 1
    serial_handle.rtscts = 0
    serial_handle.timeout = 1
    serial_handle.write_timeout = 0.2

    try:
        serial_handle.open()
        bytes_sent = serial_handle.write(bytes(kwargs['data'], 'utf-8'))
    except Exception as error:
        print(error)
    else:
        print(' >>> Sent {} bytes to {}'.format(bytes_sent, DEST_PORT))

    serial_handle.close()

Attention

Note that the /dev/ttyUSBvA variable should be changed to the serial port used in your own situation.

Example #3: Forwarding raw telegram data to another instance by API

This can be quite handy if you run multiple instances of DSMR-reader (i.e.: RaspberryPI + somewhere in cloud).

See also

DSMRREADER_PLUGINS configuration:

DSMRREADER_PLUGINS=dsmr_plugins.modules.forward_raw_telegram_to_api

Plugin file dsmr_plugins/modules/forward_raw_telegram_to_api.py (new file):

import requests
import logging

from django.dispatch import receiver

from dsmr_datalogger.signals import raw_telegram


@receiver(raw_telegram)
def handle_forward_raw_telegram_to_api(**kwargs):
    API_HOST = 'https://YOUR-DSMR-HOST'  # Note: Check whether you use HTTP or SSL (HTTPS).
    API_KEY = 'YOUR-API-KEY'
    TIMEOUT = 5  # A low timeout prevents the application from hanging, when the server is unavailable.

    try:
        # Register telegram by simply sending it to the application with a POST request.
        response = requests.post(
            '{}/api/v1/datalogger/dsmrreading'.format(API_HOST),
            headers={'X-AUTHKEY': API_KEY},
            data={'telegram': kwargs['data']},
            timeout=TIMEOUT
        )
    except Exception as error:
        return logging.error(error)

    if response.status_code != 201:
        logging.error('Server Error forwarding telegram: {}'.format(response.text))

Attention

Note that the API_HOST, API_KEY and TIMEOUT variables should be changed to your own preferences.

Example #4: Forwarding DSMR readings in JSON format to some API

Use this to send DSMR readings in JSON format to some (arbitrary) API.

See also

DSMRREADER_PLUGINS configuration:

DSMRREADER_PLUGINS=dsmr_plugins.modules.forward_json_dsmrreading_to_api

Plugin file dsmr_plugins/modules/forward_json_dsmrreading_to_api.py (new file):

import requests
import json

from django.dispatch import receiver
from django.core import serializers
from django.utils import timezone
import django.db.models.signals

from dsmr_datalogger.models.reading import DsmrReading

@receiver(django.db.models.signals.post_save, sender=DsmrReading)
def handle_forward_json_dsmrreading_to_api(sender, instance, created, raw, **kwargs):
    if not created or raw:
        return

    instance.timestamp = timezone.localtime(instance.timestamp)

    if instance.extra_device_timestamp:
        instance.extra_device_timestamp = timezone.localtime(instance.extra_device_timestamp)

    serialized = json.loads(serializers.serialize('json', [instance]))
    json_string = json.dumps(serialized[0]['fields'])

    try:
        requests.post(
            'https://YOUR-DSMR-HOST/api/endpoint/',
            data=json_string,
            # A low timeout prevents DSMR-reader from hanging, when the remote server is unreachable.
            timeout=5
        )
    except Exception as error:
        print('forward_json_dsmrreading_to_api:', error)

Example #5: Read telegrams using DSMRloggerWS API

See also

DSMRREADER_PLUGINS configuration:

DSMRREADER_PLUGINS=dsmr_plugins.modules.poll_dsmrloggerws_api

Plugin file dsmr_plugins/modules/poll_dsmrloggerws_api.py (new file):

import requests

from django.dispatch import receiver

from dsmr_backend.signals import backend_called
import dsmr_datalogger.services.datalogger


# Preverve a low timeout to prevent the entire backend process from hanging too long.
DSMRLOGGERWS_ENDPOINT = 'http://localhost/api/v1/sm/telegram'
DSMRLOGGERWS_TIMEOUT = 5


@receiver(backend_called)
def handle_backend_called(**kwargs):
    response = requests.get(DSMRLOGGERWS_ENDPOINT,
                            timeout=DSMRLOGGERWS_TIMEOUT)

    if response.status_code != 200:
        print(' [!] DSMRloggerWS plugin: Telegram endpoint failed (HTTP {}): {}'.format(
            response.status_code,
            response.text
        ))
        return

    dsmr_datalogger.services.datalogger.telegram_to_reading(data=response.text)

Attention

Note that you might need to update the http://localhost value to your own situation.