dash-spa 0.8.2

Dash Single Page Application (SPA) Framework

dash-spa

Dash/SPA is a minimal template and component suite that allows you to build complex Dash based multi-page applications with ease. The demo application includes several well known Dash demos that have been pasted into the SPA framework to show how easy it is to transition to SPA.

Dash/SPA supports Flask style Blueprints and route decorators:

Code Snippet

pip install dash-spa

from dash import html
from dash_spa import Blueprint

greetings = Blueprint('greetings')

@greetings.route('/hello')
def hello():
    return html.H2('Dash/SPA says HELLO!')

@greetings.route('/goodby')
def goodby():
    return html.H2('Dash/SPA says GOODBY!')

...

app.register_blueprint(greetings, url_prefix='/test/greetings')

Dash/SPA manages component IDs using blueprint/route based namespaces. This greatly reduces Dash component ID conflicts. A component ID is only defined once when the component is created. It is then used by reference in associated Dash callbacks:

from dash import html
import dash_bootstrap_components as dbc
import dash_holoniq_components as dhc

user_name = dbc.Input(id='user', placeholder="Enter name")
password = dhc.PasswordInput("Password", name='password', id='password', placeholder="Enter password")

btn = html.Button('Enter', id='enter', disabled=True)

@app.callback(btn.output.disabled, [user_name.input.value, password.input.value])
def _cb_enter(user_name, password):
    return not db_validate_user(user_name, password)

Dash components created outside of a blueprint route are prefixed with the enclosing modules name (__NAME__)

Routes can be protected by an arbitrary access validation function:

@admin.route('/users', title='Admin Users', access=validate_user)
def user_view(ctx):
  pass

In the example, validate_user throws an exception if the user is not signed in. This results in a 404 page being displayed

Dash/SPA includes an optional NAVBAR, configured by a simple dictionary:

NAV_BAR_ITEMS = {
    'brand' : spa.NavbarBrand('Dash/SPA','/'),
    'left' : [
        spa.NavbarLink('Global Warming','/demo/warming'),
        spa.NavbarLink('State Solar', '/demo/solar'),
        spa.NavbarLink('Ticker', '/demo/ticker?tickers=COKE'),
        spa.NavbarLink('Profile', '/user/profile'),
        spa.NavbarLink('Admin', '/admin/users'),
    ],
    'right': [
        AdminNavbarComponent()
    ],

    'footer': spa.Footer('SPA/Examples'),
}

Dash/SPA Allows easy creation of interactive forms

frm = SpaForm(ctx,'loginFrm')

email = frm.Input('Email', name='email', type='email', placeholder="Enter email")
password = frm.PasswordInput("Password", name='password', placeholder="Enter password")
button = html.Button('Sign In', type='submit')

form = frm.Form([
    email,
    password,
    button,
], title='Sign In'),


@app.callback(form.output.children, [form.input.form_data])
def _form_submit(values):
    print(values)
    return spa.NOUPDATE

Admin Blueprint

Dash/SPA Includes an optional admin blueprint that supports user registration, email authentication and login. This is provided as a demonstrator, careful consideration to the security implications should be undertaken before using it in a public website.

Views are provided that allow:

• Register, name, email, password. Verification code send by email.

• Enter the email verification code.

• Normal user login.

• Reset forgotten password, Password reset code sent by email.

• Enter password reset code.

• Enter new password, confirm new password.

• Login using new password.

• User admin table with Add, Edit and Delete. Accessible only when signed in with admin rights.

Documentation

Head over to the README for more details.

Contributing

The source code for dash-spa is available on GitHub. If you find a bug or something is unclear, we encourage you to raise an issue. We also welcome contributions, to contribute, fork the repository and open a pull request.