dash-form-factory

Generate Dash Bootstrap forms from Pydantic v2 models using a factory pattern.

Installation

pip install dash-form-factory

Or with uv:

uv add dash-form-factory

Quick Start

from typing import Annotated
from pydantic import BaseModel, Field
import dash_bootstrap_components as dbc
from dash import Dash, html, callback, Input, Output
from dash_form_factory import FormFactory, InputField

# 1. Define your Pydantic model
class ContactForm(BaseModel):
    name: Annotated[str, Field(
        "",
        title="Name",
        description="Your full name",
        json_schema_extra={"type": "text"}
    )]
    email: Annotated[str, Field(
        "",
        title="Email",
        description="Your email address",
        json_schema_extra={"type": "email"}
    )]

# 2. Create layout with InputField placeholders
layout = dbc.Card([
    dbc.CardBody([
        InputField("name"),
        InputField("email"),
        dbc.Button("Submit", id="submit")
    ])
])

# 3. Process layout with FormFactory
factory = FormFactory(ContactForm, layout)
form = factory.process_layout(factory.layout)

# 4. Create app and register callbacks
app = Dash(__name__, external_stylesheets=[dbc.themes.BOOTSTRAP])
app.layout = html.Div([form, html.Div(id="output")])

@callback(
    output=factory.produce_callback_outputs(),
    inputs=factory.produce_callback_inputs(),
)
def validate(**inputs):
    valid, outputs = factory.validate_callback(inputs)
    return outputs

Pydantic Model Requirements

Each field must include json_schema_extra with a type key:

from typing import Annotated
from pydantic import BaseModel, Field

class MyModel(BaseModel):
    field_name: Annotated[type, Field(
        default_value,
        title="Display Title",
        description="Help text shown below the field",
        json_schema_extra={"type": "field_type"}
    )]

Supported Field Types

Date Picker Example

from typing import List

date_range: Annotated[List[str], Field(
    ["2024-01-01", "2024-12-31"],
    title="Date Range",
    json_schema_extra={"type": "date-picker"}
)]

Dropdown Checklist Example

from typing import List, Literal

options: Annotated[List[Literal["opt_a", "opt_b", "opt_c"]], Field(
    [],
    title="Options",
    json_schema_extra={"type": "dropdown-checklist"}
)]

FormFactory API

Constructor

FormFactory(pymodel, layout, active=True)

• pymodel: Pydantic model class or instance
• layout: Dash component tree with InputField placeholders
• active: If False, form fields are disabled

Methods

Using with Model Instances

Pass a model instance to pre-fill form values:

instance = ContactForm(name="John", email="john@example.com")
factory = FormFactory(instance, layout)

Disabled Forms

Set active=False for read-only forms:

factory = FormFactory(ContactForm, layout, active=False)

Examples

See the examples/ directory:

• basic_form.py - Simple contact form
• advanced_form.py - All field types demo

Run examples with:

uv run python examples/basic_form.py

Comparison with dash-pydantic-form

This package differs has a signifikatn overlap to dash-pydantic-form. Yet differs on some core features:

Further it is to mention that dash-pydantic-form is much more feautre rich and mature.

Development

# Clone repository
git clone https://github.com/yourusername/dash-form-factory
cd dash-form-factory

# Install with dev dependencies
uv sync --all-groups

# Run tests
uv run pytest

# Run linting
uv run ruff check src/

# Run type checking
uv run mypy src/

License

EUPL