flet-stack 0.2.0

Decorator-based routing with view stacking for Flet applications

flet-stack

Component-based routing with automatic view stacking for Flet applications.

Features

• 🎯 Decorator-based routing - Clean, intuitive @view() decorator for route definitions
• 🔄 Observable state management - Built-in state management using @ft.observable dataclasses
• ⚡ Async support - Handle async data loading with automatic loading indicators
• 🎨 URL parameters - Extract parameters from routes like /user/{id}
• 🧩 Component-based architecture - Uses Flet's modern @ft.component pattern
• 🚀 Simple setup - Just call page.render_views(FletStack) in your app

Requirements

• Python 3.9+
• Flet >= 0.70.0.dev6281

Installation

From PyPI

pip install flet-stack

From GitHub

pip install git+https://github.com/fasilwdr/flet-stack.git

Install Specific Version

pip install git+https://github.com/fasilwdr/flet-stack.git@v0.2.0

From Source

git clone https://github.com/fasilwdr/flet-stack.git
cd flet-stack
pip install .

Quick Start

import flet as ft
from flet_stack import view, FletStack
import asyncio

# Define your routes with the @view decorator
@view("/")
@ft.component
def home_view():
    return [
        ft.Text("Home Page", size=30),
        ft.Button(
            "Go to Profile",
            on_click=lambda _: asyncio.create_task(
                ft.context.page.push_route("/profile")
            )
        ),
    ]

@view("/profile", appbar=ft.AppBar())
@ft.component
def profile_view():
    return [
        ft.Text("Profile Page", size=30),
    ]

# Run your app
ft.run(lambda page: page.render_views(FletStack))

That's it! The routing is automatically handled by FletStack.

Advanced Usage

URL Parameters

Extract parameters from your routes:

@view("/user/{user_id}")
@ft.component
def user_view(user_id):
    return [
        ft.Text(f"User Profile: {user_id}", size=30),
    ]

State Management

Use observable dataclasses to manage component state:

from dataclasses import dataclass

@ft.observable
@dataclass
class CounterState:
    count: int = 0
    
    def increment(self, e):
        self.count += 1
    
    def decrement(self, e):
        self.count -= 1

@view("/counter", state_class=CounterState, appbar=ft.AppBar())
@ft.component
def counter_view(state):
    return [
        ft.Text(f"Count: {state.count}", size=30),
        ft.Row([
            ft.Button("Decrement", on_click=state.decrement),
            ft.Button("Increment", on_click=state.increment),
        ]),
    ]

Async Data Loading

Load data asynchronously before showing your view:

@ft.observable
@dataclass
class UserState:
    user_data: dict = None

async def load_user_data(state, user_id):
    # Simulate API call
    await asyncio.sleep(1)
    state.user_data = {
        "id": user_id,
        "name": f"User {user_id}",
        "email": f"user{user_id}@example.com"
    }

@view("/user/{user_id}", state_class=UserState, on_load=load_user_data)
@ft.component
def user_detail_view(state, user_id):    
    return [
        ft.Text(f"Name: {state.user_data['name']}", size=20),
        ft.Text(f"Email: {state.user_data['email']}", size=16),
        ft.Text(f"ID: {state.user_data['id']}", size=16),
    ]

While loading, a progress indicator is automatically displayed.

Sync Data Loading

You can also use synchronous loading functions:

def load_item_info(state, category, item_id, page):
    """Sync data loading with access to page object"""
    state.info = {
        "category": category.capitalize(),
        "item_id": item_id,
        "name": f"{category.capitalize()} Item #{item_id}",
        "price": f"${int(item_id) * 10}.99"
    }

@view(
    "/category/{category}/item/{item_id}",
    state_class=ItemState,
    on_load=load_item_info
)
@ft.component
def item_view(state, category, item_id):
    return [
        ft.Text(f"{state.info['name']}", size=20),
        ft.Text(f"Price: {state.info['price']}", size=18),
    ]

View Configuration

Pass additional Flet view properties:

@view(
    "/settings",
    appbar=ft.AppBar(title=ft.Text("Settings")),
    bgcolor=ft.Colors.BLUE_GREY_50,
    padding=20,
    horizontal_alignment=ft.CrossAxisAlignment.CENTER,
    vertical_alignment=ft.MainAxisAlignment.CENTER,
)
@ft.component
def settings_view():
    return [ft.Text("Settings", size=30)]

Multiple URL Parameters

Handle routes with multiple parameters:

@view("/category/{category}/item/{item_id}")
@ft.component
def item_view(category, item_id):
    return [
        ft.Text(f"Category: {category}", size=20),
        ft.Text(f"Item ID: {item_id}", size=20),
    ]

API Reference

@view Decorator

@view(route: str, state_class: Type = None, on_load: Optional[Callable] = None, **view_kwargs)

• route: The route path for this view (e.g., /, /user/{user_id})
• state_class: Optional dataclass decorated with @ft.observable for state management
• on_load: Optional function to call before rendering (can be async)
  • Can accept parameters: state, page, and any URL parameters
• view_kwargs: Additional kwargs passed to ft.View (e.g., appbar, bgcolor, padding)

FletStack Component

Main component that manages the routing stack and renders views.

# Option 1: Direct render
ft.run(lambda page: page.render_views(FletStack))

# Option 2: In main function
def main(page: ft.Page):
    page.title = "My App"
    page.render_views(FletStack)

ft.run(main)

Navigation

Use asyncio.create_task with ft.context.page.push_route:

# Navigate to a route
asyncio.create_task(ft.context.page.push_route("/profile"))

# In button click handler
ft.Button(
    "Go to Profile",
    on_click=lambda _: asyncio.create_task(
        ft.context.page.push_route("/profile")
    )
)

Examples

Check the examples/ directory for more detailed examples:

• basic_example.py - Simple routing and navigation
• advanced_example.py - State management, async loading, and URL parameters

How It Works

flet-stack provides a FletStack component that:

1. Registers all @view decorated functions
2. Manages a navigation stack for route changes
3. Handles state management with observable dataclasses
4. Manages async/sync loading with automatic progress indicators
5. Renders views with proper navigation support

Contributing

Contributions are welcome! Please feel free to submit a Pull Request.

License

This project is licensed under the MIT License - see the LICENSE file for details.

Acknowledgments

Built on top of the amazing Flet framework by Feodor Fitsner.

Support

If you encounter any issues or have questions:

• Open an issue on GitHub
• Check the examples directory
• Read the Flet documentation