Writing Plugins¶

You can extend FlexMeasures with functionality like UI pages or CLI functions.

A FlexMeasures plugin works as a Flask Blueprint.

Todo

We’ll use this to allow for custom forecasting and scheduling algorithms, as well.

How it works¶

Use the config setting FLEXMEASURES_PLUGIN_PATHS to point to your plugin(s).

Here are the assumptions FlexMeasures makes to be able to import your Blueprint:

The plugin folder contains an __init__.py file.
In this init, you define a Blueprint object called <plugin folder>_bp.

We’ll refer to the plugin with the name of your plugin folder.

Showcase¶

Here is a showcase file which constitutes a FlexMeasures plugin. We imagine that we made a plugin to implement some custom logic for a client.

We created the file <some_folder>/our_client/__init__.py. So, our_client is the plugin folder and becomes the plugin name. All else that is needed for this showcase (not shown here) is <some_folder>/our_client/templates/metrics.html, which works just as other FlexMeasures templates (they are Jinja2 templates and you can start them with {% extends "base.html" %} for integration into the FlexMeasures structure).

We demonstrate adding a view which can be rendered via the FlexMeasures base templates.
We also showcase a CLI function which has access to the FlexMeasures app object. It can be called via flexmeasures our_client test.

from flask import Blueprint, render_template, abort

from flask_security import login_required
from flexmeasures.ui.utils.view_utils import render_flexmeasures_template


our_client_bp = Blueprint('our_client', 'our_client',
                          template_folder='templates')


# Showcase: Adding a view

@our_client_bp.route('/metrics')
@login_required
def metrics():
    msg = "I am part of FM !"
    # Note that we render via the in-built FlexMeasures way
    return render_flexmeasures_template(
        "metrics.html",
        message=msg,
    )


# Showcase: Adding a CLI command

import click
from flask import current_app
from flask.cli import with_appcontext


our_client_bp.cli.help = "Our client commands"

@our_client_bp.cli.command("test")
@with_appcontext
def oc_test():
    print(f"I am a CLI command, part of FlexMeasures: {current_app}")

Note

Plugin views can also be added to the FlexMeasures UI menu ― just name them in the config setting FLEXMEASURES_LISTED_VIEWS.

Using other files in your plugin¶

Say you want to include other Python files in your plugin, importing them in your __init__.py file. This can be done if you put the plugin path on the import path. Do it like this in your __init__.py:

import os
import sys

HERE = os.path.dirname(os.path.abspath(__file__))
sys.path.insert(0, HERE)

from my_other_file import my_function