03: Greeting

A component that takes a constructor argument and renders it. Shows how to parameterize a component without resorting to props-as-strings or factory functions. You just pass kwargs to __init__ and store them on self.

The script

from weaverlet.base import WeaverletComponent, WeaverletApp
from dash import html

class GreetingComponent(WeaverletComponent):

    def __init__(self, greeting_name, **kwargs):
        super().__init__(**kwargs)
        self.greeting_name = greeting_name

    def get_layout(self):
        return html.Div(f'hello {self.greeting_name}!')

greeting_component = GreetingComponent(greeting_name='Oscar')
wapp = WeaverletApp(root_component=greeting_component)
wapp.app.run(port=8089)

Expected output

The page shows the text "hello Oscar!".

Notes

• Components are regular Python classes. They receive arguments via __init__ like any other.
• Always call super().__init__(**kwargs) first to give WeaverletComponent a chance to set up its DAG bookkeeping. Pass **kwargs through so callers can still set name=... and other base-class options.
• The instance is a regular Python object: store data on self, reference it in get_layout. There's no equivalent of React props because there's no equivalent of React re-rendering.

Try it locally

pip install weaverlet
python greeting.py

See also

• Components. Concept
• WeaverletComponent: API reference