FletEasy Class¶

The FletEasy class is the core component of Flet-Easy that provides a simplified and powerful way to build Flet applications with advanced routing, authentication, and configuration capabilities.

Overview¶

The FletEasy class serves as the main application controller, offering:

Advanced Routing System: Dynamic routes with parameter validation
Authentication & Security: JWT support and route protection
Event Management: Keyboard and resize event handling
Middleware Support: Request/response processing pipeline
Automatic Page Discovery: Auto-routing from directory structures
Responsive Design: Built-in responsive control system

Class Definition¶

class FletEasy:
    def __init__(
        self,
        route_prefix: str = "",
        route_init: str = "/",
        route_login: str = "/login",
        on_keyboard: bool = False,
        on_resize: bool = False,
        secret_key: Optional[SecretKey] = None,
        auto_logout: bool = False,
        path_views: Optional[Path] = None,
        logger: bool = False
    )

Parameters¶

`route_prefix`¶

Type: str
Default: ""
Description: Base prefix for all routes in your application

Example:

app = fs.FletEasy(route_prefix="/myapp")
# Routes will be: /myapp/home, /myapp/about, etc.

`route_init`¶

Type: str
Default: "/"
Description: Initial route when the application starts

Example:

app = fs.FletEasy(route_init="/dashboard")
# App starts at /dashboard instead of /

`route_login`¶

Type: str
Default: "/login"
Description: Redirect route for protected pages when user is not authenticated

Example:

app = fs.FletEasy(route_login="/auth/signin")
# Protected routes redirect to /auth/signin

`on_keyboard`¶

Type: bool
Default: False
Description: Enable global keyboard event handling

Example:

app = fs.FletEasy(on_keyboard=True)

@app.config_event_handler
def handle_events(data: fs.Datasy):
    # Access keyboard events via data.on_keyboard_event
    if data.on_keyboard_event.key() == "Escape":
        data.page.window_close()

`on_resize`¶

Type: bool
Default: False
Description: Enable window resize event handling

Example:

app = fs.FletEasy(on_resize=True)

@app.config_event_handler
def handle_events(data: fs.Datasy):
    # Access resize events via data.on_resize
    width = data.on_resize.width()
    height = data.on_resize.height()

`secret_key`¶

Type: Optional[SecretKey]
Default: None
Description: Secret key for JWT authentication and secure storage

Example:

from flet_easy import SecretKey

secret = SecretKey("your-secret-key-here")
app = fs.FletEasy(secret_key=secret)

`auto_logout`¶

Type: bool
Default: False
Description: Automatically logout users when JWT expires

`path_views`¶

Type: Optional[Path]
Default: None
Description: Directory path for automatic page discovery

Example:

from pathlib import Path

app = fs.FletEasy(path_views=Path("views"))
# Automatically discovers pages in ./views/ directory

`logger`¶

Type: bool
Default: False
Description: Enable detailed logging for debugging

Core Methods¶

`@app.page()` Decorator¶

Register a page with routing capabilities.

@app.page(
    route: str,
    title: Optional[str] = None,
    index: Optional[int] = None,
    page_clear: bool = False,
    share_data: bool = False,
    protected_route: bool = False,
    custom_params: Optional[Dict[str, Callable]] = None,
    middleware: Optional[Middleware] = None,
    cache: bool = False
)
def page_function(data: fs.Datasy, **params):
    # Page implementation
    pass

Parameters:

route: URL pattern (supports dynamic parameters)
title: Page title for browser/window
index: Define the index of the page, use in controls like ft.NavigationBar and ft.CupertinoNavigationBar.
page_clear: Clear previous pages from navigation stack
share_data: Enable data sharing between pages
protected_route: Require authentication
custom_params: Custom parameter validators
middleware: Page-specific middleware
cache: Preserve page state during navigation

`@app.view()` Decorator¶

Configure the global view template.

@app.view
def global_view(data: fs.Datasy):
    return fs.Viewsy(
        appbar=ft.AppBar(title=ft.Text("My App")),
        drawer=ft.NavigationDrawer(...),
        # ... other view properties
    )

`@app.login()` Decorator¶

Configure authentication logic.

@app.login
def auth_handler(data: fs.Datasy):
    # Check if user is authenticated
    token = data.page.client_storage.get("auth_token")
    if token and verify_token(token):
        return True
    return False

`@app.config_event_handler()` Decorator¶

Configure global event handlers.

@app.config_event_handler
def event_handler(data: fs.Datasy):
    page = data.page
    def key_event(e: ft.KeyboardEvent):
        if e.key == "F11":
            page.window.full_screen = not page.window.full_screen
            page.update()

    page.on_keyboard_event = key_event

Complete Example¶

Here's a comprehensive example showing all major features:

import flet as ft
import flet_easy as fs

# Initialize app with configuration
import flet as ft
import flet_easy as fs

# Minimal setup with auth and routes
app = fs.FletEasy(
    route_prefix="/myapp",
    route_init="/myapp/home",
    route_login="/myapp/login",
)


@app.view
def page_view(data: fs.Datasy):
    return ft.View(
        controls=[
            ft.Container(
                content=ft.Container(
                    content=ft.Column(
                        # controls=controls,
                        horizontal_alignment=ft.CrossAxisAlignment.CENTER,
                        spacing=16,
                    ),
                    width=640,
                    padding=24,
                    border_radius=16,
                    border=ft.border.all(1, ft.Colors.GREY_200),
                ),
                alignment=ft.alignment.center,
                padding=24,
            )
        ],
        appbar=ft.AppBar(
            title=ft.Text("My App", color=ft.Colors.WHITE),
            bgcolor=ft.Colors.INDIGO_600,
            actions=[
                ft.IconButton(
                    ft.Icons.HOME, icon_color=ft.Colors.WHITE, on_click=data.go(data.route_init)
                ),
                ft.IconButton(
                    ft.Icons.LOGOUT, icon_color=ft.Colors.WHITE, on_click=lambda _: data.logout("auth_token")
                ),
            ],
        ),
    )


@app.login
def authenticate(data: fs.Datasy):
    return data.page.client_storage.get("auth_token") is not None


@app.config_event_handler
def event_handler(data: fs.Datasy):
    page = data.page

    def key_event(e: ft.KeyboardEvent):
        if e.key == "F11":
            page.window.full_screen = not page.window.full_screen

        if e.key == "Escape":
            page.window.close()

        page.update()

    page.on_keyboard_event = key_event


@app.page("/home", title="Home")
def home_page(data: fs.Datasy):
    view = data.view
    view.appbar.title.value = "My App"

    view.controls[0].content.content.controls = [
        ft.Text("Welcome!", size=28, weight=ft.FontWeight.BOLD),
        ft.Row(
            [
                ft.ElevatedButton("Profile", on_click=data.go("/myapp/profile/1")),
                ft.ElevatedButton("Admin", on_click=data.go("/myapp/admin")),
            ],
            spacing=12,
        ),
    ]
    return view


@app.page("/profile/{user_id:int}", title="Profile", protected_route=True)
def profile_page(data: fs.Datasy, user_id: int):
    view = data.view
    view.appbar.title.value = "Profile"
    view.controls[0].content.content.controls = [
        ft.Text(f"User ID: {user_id}", size=24),
        ft.ElevatedButton("Back", on_click=data.go(data.route_init)),
    ]
    return view


@app.page("/login", title="Login")
def login_page(data: fs.Datasy):
    u = ft.TextField(label="Username")
    p = ft.TextField(label="Password", password=True)

    def do_login(_):
        if u.value == "admin" and p.value == "admin":
            data.login("auth_token", {"user": u.value}, next_route=data.route_init)
        else:
            data.page.open(ft.SnackBar(content=ft.Text("Invalid credentials")))

    view = data.view
    view.appbar.title.value = "Login"
    view.controls[0].content.content.controls = [
        ft.Text("Login", size=26, weight=ft.FontWeight.BOLD),
        u,
        p,
        ft.ElevatedButton("Login", on_click=do_login),
    ]
    return view


@app.page("/admin", title="Admin", protected_route=True)
def admin_page(data: fs.Datasy):
    view = data.view
    view.appbar.title.value = "Admin"
    view.controls[0].content.content.controls = [
        ft.Text("Admin Panel", size=26, weight=ft.FontWeight.BOLD),
        ft.Text("Protected content"),
        ft.ElevatedButton("Logout", on_click=lambda _: data.logout("auth_token")),
    ]
    return view


if __name__ == "__main__":
    app.run()

🎬 Demo¶

Step-by-step explanation of the example¶

Imports Code excerpt:

import flet as ft
import flet_easy as fs

What it does: - Import Flet (UI toolkit) and Flet-Easy (routing, views, helpers).

App instance (fs.FletEasy)

Code excerpt:

app = fs.FletEasy(
    route_prefix="/myapp",
    route_init="/myapp/home",
    route_login="/myapp/login",
)

What it does: - Sets a route prefix for grouping. - Defines the initial route and the login route used by protected pages.

Global view with @app.view

Code excerpt:

@app.view
def page_view(data: fs.Datasy):
    return ft.View(
        controls=[ ... ],
        appbar=ft.AppBar(
            title=ft.Text("My App", color=ft.Colors.WHITE),
            bgcolor=ft.Colors.INDIGO_600,
            actions=[ ... ],
        ),
    )

What it does: - Provides a shared base layout (container + AppBar) for all pages. - Each page later customizes data.view (title and central content).

Authentication with @app.login

Code excerpt:

@app.login
def authenticate(data: fs.Datasy):
    return data.page.client_storage.get("auth_token") is not None

What it does: - Returns True if a token exists. Protected routes redirect to route_login if not authenticated.

Global event handler with @app.config_event_handler

Code excerpt:

@app.config_event_handler
def event_handler(data: fs.Datasy):
    page = data.page

    def key_event(e: ft.KeyboardEvent):
        if e.key == "F11":
            page.window.full_screen = not page.window.full_screen

        if e.key == "Escape":
            page.window.close()

        page.update()

    page.on_keyboard_event = key_event

What it does: - Adds global keyboard shortcuts: F11 toggles full screen, Escape closes the window.

Home page @app.page("/home")

Code excerpt:

@app.page("/home", title="Home")
def home_page(data: fs.Datasy):
    view = data.view
    view.appbar.title.value = "My App"
    view.controls[0].content.content.controls = [
        ft.Text("Welcome!", size=28, weight=ft.FontWeight.BOLD),
        ft.Row([
            ft.ElevatedButton("Profile", on_click=data.go("/myapp/profile/1")),
            ft.ElevatedButton("Admin", on_click=data.go("/myapp/admin")),
        ], spacing=12),
    ]
    return view

What it does: - Sets the title and the central content with navigation buttons.

Profile page @app.page("/profile/{user_id:int}") (protected)

Code excerpt:

@app.page("/profile/{user_id:int}", title="Profile", protected_route=True)
def profile_page(data: fs.Datasy, user_id: int):
    view = data.view
    view.appbar.title.value = "Profile"
    view.controls[0].content.content.controls = [
        ft.Text(f"User ID: {user_id}", size=24),
        ft.ElevatedButton("Back", on_click=data.go(data.route_init)),
    ]
    return view

What it does: - Receives a typed parameter (user_id) and shows a back button to the initial route.

Login page @app.page("/login")

Code excerpt:

@app.page("/login", title="Login")
def login_page(data: fs.Datasy):
    u = ft.TextField(label="Username")
    p = ft.TextField(label="Password", password=True)

    def do_login(_):
        if u.value == "admin" and p.value == "admin":
            data.login("auth_token", {"user": u.value}, next_route=data.route_init)
        else:
            data.page.open(ft.SnackBar(content=ft.Text("Invalid credentials")))

    view = data.view
    view.appbar.title.value = "Login"
    view.controls[0].content.content.controls = [
        ft.Text("Login", size=26, weight=ft.FontWeight.BOLD),
        u, p,
        ft.ElevatedButton("Login", on_click=do_login),
    ]
    return view

What it does: - Shows a simple login form. On success, stores a token and redirects; otherwise, shows a SnackBar.

Admin page @app.page("/admin") (protected)

Code excerpt:

@app.page("/admin", title="Admin", protected_route=True)
def admin_page(data: fs.Datasy):
    view = data.view
    view.appbar.title.value = "Admin"
    view.controls[0].content.content.controls = [
        ft.Text("Admin Panel", size=26, weight=ft.FontWeight.BOLD),
        ft.Text("Protected content"),
        ft.ElevatedButton("Logout", on_click=lambda _: data.logout("auth_token")),
    ]
    return view

What it does: - Shows protected content and provides a logout action.

App start

Code excerpt:

if __name__ == "__main__":
    app.run()

What it does: - Starts the Flet-Easy app and registers all handlers.

With this approach, you define the layout once (in @app.view) and, in each page, focus on updating the title and content. Authentication and keyboard shortcuts are configured globally.

Best Practices¶

Route Organization¶

{{ ... }}
app = fs.FletEasy(route_prefix="/app")

# Group related routes
@app.page("/app/users/list")
@app.page("/app/users/{id:int}")
@app.page("/app/users/{id:int}/edit")

Performance Optimization¶

# Use caching for static pages
@app.page("/about", cache=True)
def about_page(data: fs.Datasy):
    # This page state will be preserved
    pass

# Use page_clear for navigation resets
@app.page("/home", page_clear=True)
def home_page(data: fs.Datasy):
    # Clears navigation history
    pass

Advanced Configuration¶

Custom Parameter Validators¶

def validate_email(email: str) -> bool:
    return "@" in email and "." in email

@app.page(
    "/user/{email:emailValidator}",
    custom_params={"emailValidator": validate_email}
)
def user_page(data: fs.Datasy, email: str):
    # email parameter is validated before this function runs
    pass

Middleware Integration¶

class AuthMiddleware(fs.MiddlewareRequest):
    def before_request(self):
        if not self.data.page.client_storage.get("auth_token"):
            return fs.Redirect("/login")

@app.page("/protected", middleware=[AuthMiddleware])
def protected_page(data: fs.Datasy):
    pass

This comprehensive guide covers all aspects of the FletEasy class. For more specific examples and advanced use cases, refer to the other sections of this documentation.

FletEasy Class¶

Overview¶

Class Definition¶

Parameters¶

route_prefix¶

route_init¶

route_login¶

on_keyboard¶

on_resize¶

secret_key¶

auto_logout¶

path_views¶

logger¶

Core Methods¶

@app.page() Decorator¶

@app.view() Decorator¶

@app.login() Decorator¶

@app.config_event_handler() Decorator¶

Complete Example¶

🎬 Demo¶

Step-by-step explanation of the example¶

Best Practices¶

Route Organization¶

Performance Optimization¶

Advanced Configuration¶

Custom Parameter Validators¶

Middleware Integration¶

`route_prefix`¶

`route_init`¶

`route_login`¶

`on_keyboard`¶

`on_resize`¶

`secret_key`¶

`auto_logout`¶

`path_views`¶

`logger`¶

`@app.page()` Decorator¶

`@app.view()` Decorator¶

`@app.login()` Decorator¶

`@app.config_event_handler()` Decorator¶