Flet-Easy Documentation¶

Flet-Easy is a comprehensive Python framework that extends Flet with powerful features for building modern desktop, web, and mobile applications. It provides a clean, intuitive API with advanced routing, authentication, middleware, page caching, and responsive design capabilities — all with zero breaking changes when upgrading Flet versions.

Key Features¶

• 🛣️ Advanced Routing: Dynamic routes, NavigationBar integration, regex-based parameter validation, and custom 404 pages
• 💾 Page Caching: Optional per-page state preservation across navigation for seamless user experience
• 🔐 Built-in Authentication: JWT support (HS256 / RS256 / RS512) with automatic session management
• 🔧 Enhanced Middleware: Class-based and functional middleware with global and per-page application
• 🎭 Dual Rendering Modes: Supports both Declarative (@ft.component) and Imperative routing seamlessly
• 🔒 Concurrency-Safe: Session isolation via contextvars — no data leakage in multi-user async environments
• 🎛️ Dynamic Controls: Real-time UI updates with dynamic_control() — works with cached pages
• 📱 Responsive Design: ResponsiveControlsy and on_resize hooks for adaptive desktop/tablet/mobile layouts
• ⚡ High Performance: O(1) exact route lookup, lazy-loaded components, and intelligent view caching
• 🎨 Sub-router Support: Organize pages into independent modules with AddPagesy and route prefixes
• 🛠️ Developer Tools: CLI (fs init) for project scaffolding, code generation, and app templates
• 🐍 Python 3.9+: Uses modern Python generics and type hints out of the box
• 📦 Flet 0.27+ Compatible: Tested from Flet 0.27.* all the way to 0.80+ with automatic fallbacks
• 📚 Comprehensive Documentation: Step-by-step guides, API reference, and practical examples

Quick Start¶

Installation¶

# Basic installation
pip install flet-easy

# Full installation with all features
pip install flet-easy[all] --upgrade

Your First App¶

import flet as ft
import flet_easy as fs

# 1. Initialize Flet-Easy
# We set the initial route to "/home"
app = fs.FletEasy(route_init="/home")

# 2. Define a Global View
# This layout (AppBar, NavigationBar, etc.) will be shared across pages
@app.view
def main_view(data: fs.Datasy):
    return fs.Viewsy(
        appbar=ft.AppBar(
            title=ft.Text("My Flet-Easy App"),
            bgcolor=ft.Colors.BLUE,
        ),
        navigation_bar=ft.NavigationBar(
            destinations=[
                ft.NavigationBarDestination(icon=ft.Icons.HOME, label="Home"),
                ft.NavigationBarDestination(icon=ft.Icons.INFO, label="About"),
            ],
            on_change=data.go_navigation_bar, # Handles automatic routing via index
        ),
        bgcolor=ft.Colors.GREY_50,
    )

# 3. Create the Home Page
@app.page("/home", title="Home", index=0) # index=0 matches the first Nav interface
def home_page(data: fs.Datasy):
    data.view.appbar.title = ft.Text("Welcome Home! 🏠")

    return ft.View(
        controls=[
            ft.Text("Welcome to Flet-Easy! 🎉", size=30, weight=ft.FontWeight.BOLD),
            ft.Text("Now with page caching and NavigationBar support!", size=16),
            ft.ElevatedButton(
                "Go to About",
                on_click=lambda _: data.go_route("/about"), # Direct navigation
            ),
        ],
        appbar=data.view.appbar,
        navigation_bar=data.view.navigation_bar,
        vertical_alignment="center",
        horizontal_alignment="center",
    )

# 4. Create the About Page
@app.page("/about", title="About", index=1)
def about_page(data: fs.Datasy):
    data.view.appbar.title = ft.Text("About Flet-Easy")

    return ft.View(
        controls=[
            ft.Text("About Flet-Easy", size=24),
            ft.Text("Build amazing apps with Python and new caching features!"),
            ft.ElevatedButton("← Back Home", on_click=lambda _: data.go_back()),
        ],
        appbar=data.view.appbar,
        navigation_bar=data.view.navigation_bar,
        vertical_alignment="center",
        horizontal_alignment="center",
    )

# 5. Run the Application
if __name__ == "__main__":
    app.run()

Demo¶

What's New in v0.3.0¶

Major Features¶

• NavigationBar Integration: Built-in support for ft.NavigationBar with automatic routing
• Page Caching System: Optional state preservation to maintain UI state across navigation
• Enhanced Middleware: Class-based middleware with page-specific application support
• Dynamic Controls: Real-time UI updates with dynamic_control() method
• Performance Improvements: Optimized route loading and middleware execution

New Methods¶

• page_reload() - Reset page to default state
• dynamic_control() - Real-time control updates
• go_navigation_bar() - Handle NavigationBar events
• go_route() - Direct route navigation

⚡ API Improvements¶

• go_back() and logout() now execute directly
• Enhanced Pagesy with index and cache parameters
• Python 3.9+ compatibility with modern built-in generics
• Flet 0.27+ compatibility — automatic fallbacks for older API surfaces
• Concurrency-safe middleware — contextvars isolation per async task
• Strict type safety — fully passes ty check with zero # type: ignore comments

→ View complete changelog