Quickstart

Suppose you have installed the Flask-PluginKit. If you do not, head over to the Installation section.

The first one is to initalize it directly:

from flask_pluginkit import PluginManager, Flask
app = Flask(__name__)
pm = PluginManager(app)

where as the second one is to use the factory pattern:

from flask_pluginkit import PluginManager, Flask
app = Flask(__name__)
pm = PluginManager()
pm.init_app(app)

Plugin Structure

After the first step is done, you can start developing your first plugin.

The plugin is a legal python package that needs to define some metadata and use register to return the extension point, more see Plugin Structure

For example, the structure of small plugin can look like this:

my_plugin
|-- __init__.py

the structure of a more complex plugin can also look like this:

my_plugin
├── __init__.py
├── static
│   └── example
│       └── demo.css
└── templates
    └── example
        └── demo.html

Hello World

For a better understanding you can also have a look at the example, it contains a local plugin and a third party plugin.

Now, let’s start with a simple plugin example. The plugin name is helloworld.

This simple helloworld example can be found here.

First, the developer wrote a simple plugin web application with only one app.py, an index view function, and the content is:

# -*- coding: utf-8 -*-

from flask import Flask
from flask_pluginkit import PluginManager

app = Flask(__name__)
pm = PluginManager(app)

@app.route('/')
def index():
    return 'hello world'

Now, we want to limit when accessing the index view (ie /), if ip is 127.0.0.1, then redirect to /limit, proceed as follows:

1. Create helloworld directory

$ mkdir -p plugins/helloworld
$ touch plugins/__init__.py plugins/helloworld/__init__.py

2. Write __init__.py for the helloworld plugin, content is:

# -*- coding: utf-8 -*-

from flask import Blueprint, jsonify, request, redirect, url_for, make_response

__plugin_name__ = "helloworld"
__version__ = "0.1.0"
__author__ = "staugur"

bp = Blueprint("helloworld", "helloworld")

@bp.route("/limit")
def limit():
    return jsonify(dict(status=0, message="Access Denial"))

def limit_handler():
    """I am running in before_request"""
    ip = request.headers.get('X-Real-Ip', request.remote_addr)
    if request.endpoint == "index" and ip == "127.0.0.1":
        resp = make_response(redirect(url_for("helloworld.limit")))
        resp.is_return = True
        return resp

def register():
    return {
        "bep": dict(blueprint=bp, prefix=None),
        "hep": dict(before_request=limit_handler)
    }

3. Run

The current web application structure is as follows:

demo
├── app.py
└── plugins
    ├── helloworld
    │   └── __init__.py # Plugin core code file
    └── __init__.py     # Only an empty file

Run app:

$ FLASK_ENV=development FLASK_APP=app.py flask run --no-reload

4. Testing

   

For details, see Tutorial