shiny_validate

Overview

This is a python implementation of shinyvalidate, which provides input validation for Shiny for Python applications.

Installation

Install from Pypi with:

pip install shiny_validate

Or, you can install the latest development version from GitHub:

pip install git+https://github.com/posit-dev/py-shiny-validate.git

Basic usage

To add validation to your Shiny app, you need to:

1. Create an InputValidator object: iv = InputValidator()

2. Add one or more validation rules to the InputValidator: iv.add_rule("title", check.required())

3. Turn the validator on: iv.enable()

That's all you need to do to get validation messages to show up.

from shiny import App, ui, render, req
from shiny_validate import InputValidator, check

app_ui = ui.page_fluid(
    ui.input_text("name", "Name"),
    ui.input_text("email", "Email"),
    ui.output_text("greeting"),
)


def server(input, output, session):
    iv = InputValidator()

    iv.add_rule("name", check.required())
    iv.add_rule("email", check.required())
    iv.add_rule("email", check.email())
    iv.enable()

    @render.text
    def greeting():
        req(iv.is_valid())
        return f"Nice to meet you, {input.name()} <{input.email()}>!"


app = App(app_ui, server)

You can also use the .is_valid() method to ensure that the inputs are valid before rendering an output:

@render.plot
def plot():
    req(iv.is_valid())
    # Build and return a plot if the inputs are valid