Flet - build real-time multi-platform apps in the language you know

Flet is the next iteration of Pglet project.

Pglet demonostrated there is a strong interest to write web apps in Python.

Unlike other cross-platform GUI frameworks for Python (Kivy, Beeware) Flet does not re-invent the wheel by making its own widgets, but instead it's based on Flutter by Google, so apps built with Flet look beautiful and professional without any efforts. Out-of-the-box Flutter implements Material and Cupertino widgets for building Android and iOS UI respectively. While Material widgets work great for building Web and Desktop apps too there are platform-specific widgets available from 3rd-party developers: Fluent UI for Windows, macOS UI for macOS. We are going to implement them in the future versions of Flet in the form or "adaptive" controls.

Multi-user always-connected apps. Look at apps on your phone... With Flet we will try to explore a different model of building and delivering apps.

Why new project?

Pglet is for web apps and is based on Fluent UI React components.

Flet is for web, desktop and mobile platforms and is based on Flutter.

Fluent UI is mostly an internal project...

Flutter is fresh and awesome ... Flutter is ideal for Single Page Apps (SPA). Many developers criticize Flutter for rendering everything on canvas making SEO impossible. But I personally see rendering on canvas as an advantage: 1) the app looks less clunky, 2) the app looks the same as on desktop and mobile. Non-selectable text? Have you ever tried to select something in AWS or Azure console? If you strongly need SEO then you should choose HTML-based framework such as Next.js or similar. You obviously don't need SEO for your internal dashboard, game or admin panel.

Flutter is broader. We'll start with Material design and then add platform-specific controls: Fluent UI for Windows, macOS UI for macOS and Cupertino widgets for iOS. We could probably implement "adaptive" Fler controls which look-n-feel depends on the platform the app is running on.

Flutter gives precise layout. No more hacks with vertical alignment or horizontal alignment in nested divs.

Flutter will give access to mobile experiences: camera, location services, accelerometer, etc.

Flet is language-agnostic. It includes DOM server (Fletd) which translates language-specific DOM changes to commands and then into Flutter widgets.

Flet is an opinionated framework based on Flutter. Flutter is extremely powerful and flexible, but has a steep learning curve especially for developers without React experience. Flet hides that complexity by replacing Flutter's declarative model (re-build a UI tree on app state changes) with an imperative (modify UI tree as program progresses).

A lot of renamings would create a mess in a project repo - it's easier to start over in a new repository.

Less scope.

A lot of functionality was added to support Bash: a custom protocol via named pipes with commands serialization/deserialization, CLI support with pglet page and pglet app commands. It's not necessary anymore with high level languages such as Python which communicate with Flet server via WebSockets directly.

With Flet we are switching to monorepo storing Flet server, Flutter client and all language bindings (SDKs). Every CI build and release creates the same, unique version for all the apps and components.

Why changing name?

• Confusing name. It's been almost a year and I haven't used to the name yet. Is it a "page-let", "p-g-let" or "piglet"? Is there connection to "PostgreSQL" or Paul Graham? On the other hand "flet" is short, simple and easy to pronounce.

Migration

• All sizes are float numbers. Not "px", "pt", "rem", "%" or something else from CSS, but just numbers meaning "virtual pixels".
• All percentage values are rational numbers between 0 and 1, i.e. 0.5 means 50%.