Elm UI Progress Example - Elm-ui Typing CST Test
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Elm UI Progress Example — Elm-ui Code
A slider that updates a visual progress bar.
module Main exposing (main)
import Browser
import Element exposing (..)
import Element.Events exposing (onInput)
-- MODEL
type alias Model =
{ progress : Float }
initialModel : Model
initialModel = { progress = 0 }
-- UPDATE
type Msg = Update Float
update : Msg -> Model -> Model
update msg model =
case msg of Update val -> { model | progress = val }
-- VIEW
view : Model -> Element Msg
view model =
column [ spacing 10, padding 20, alignCenter ]
[ el [ width fill, height (px 20), Background.color blue, padding 0 ] (el [] (text (String.fromFloat model.progress)))
, Element.input [ onInput (str -> Update (String.toFloat str |> Result.withDefault 0)) ]
]
-- MAIN
main = Browser.sandbox { init = initialModel, update = update, view = view }Elm-ui Language Guide
Elm UI is a library for building web interfaces in Elm, focusing on layout and styling in a declarative, type-safe way without relying on CSS.
Primary Use Cases
- ▸Building web interfaces in Elm
- ▸Creating responsive layouts without CSS
- ▸Developing reusable UI components
- ▸Prototyping web app designs quickly
- ▸Type-safe styling and spacing
Notable Features
- ▸Declarative layout syntax
- ▸Completely typed in Elm
- ▸Composable UI boxes
- ▸Supports responsive and flexible layouts
- ▸Eliminates manual CSS for many tasks
Origin & Creator
Elm UI was created by the Elm community, with Evan Czaplicki (creator of Elm) influencing its design for declarative UI patterns.
Industrial Note
Elm UI is used primarily in Elm applications to replace CSS for layout management, providing strong type safety and predictable UI behavior.
Quick Explain
- ▸Elm UI lets developers describe UIs using Elm code, avoiding manual CSS and HTML.
- ▸It uses a box-based layout system inspired by Flexbox but fully typed in Elm.
- ▸Provides composable, reusable UI elements with built-in styling support.
- ▸Ensures type safety for layout, spacing, and styling decisions.
- ▸Widely used in Elm projects for clean, maintainable, and responsive UI design.
Core Features
- ▸Box layout system for alignment and spacing
- ▸Styling via Elm functions and records
- ▸Composability of UI elements
- ▸Type-safe units and dimensions
- ▸No need for CSS classes or ids
Learning Path
- ▸Learn Elm basics and functional programming
- ▸Understand Elm Architecture (TEA)
- ▸Learn Elm UI Box layout system
- ▸Practice building small components
- ▸Compose full UI layouts with Elm UI
Practical Examples
- ▸Build a centered login form
- ▸Create a responsive navigation bar
- ▸Design a dashboard with cards and grids
- ▸Compose reusable button components
- ▸Implement a responsive footer layout
Comparisons
- ▸Elm UI vs plain Elm HTML: type-safe layout vs manual CSS
- ▸Elm UI vs React: functional layout vs JSX and CSS
- ▸Elm UI vs Blazor: Elm-only functional paradigm vs C# and WebAssembly
- ▸Elm UI vs Flutter Web: Elm typed layout vs Dart UI framework
- ▸Elm UI vs CSS frameworks: typed and composable vs class-based styling
Strengths
- ▸Strong type safety ensures layout correctness
- ▸Reduces runtime layout errors
- ▸Declarative and composable UI design
- ▸Eliminates CSS complexity
- ▸Works seamlessly with Elm’s functional paradigm
Limitations
- ▸Limited to Elm applications
- ▸Does not support all CSS features
- ▸Smaller ecosystem compared to HTML/CSS frameworks
- ▸Learning curve for functional layout thinking
- ▸Less flexible for highly custom or complex visual designs
When NOT to Use
- ▸Projects not using Elm
- ▸Highly customized CSS animations
- ▸Existing large CSS frameworks
- ▸Dynamic third-party JS UI libraries
- ▸Designs requiring low-level DOM manipulations
Cheat Sheet
- ▸Element.layout - root UI layout
- ▸Element.column/row - vertical/horizontal boxes
- ▸Element.spacing - padding/margin
- ▸Element.el - wrap child elements
- ▸Element.width/height - set dimensions
FAQ
- ▸Is Elm UI free?
- ▸Yes - open-source under BSD license.
- ▸Does it replace CSS?
- ▸It can handle most layout and styling, but advanced CSS may still be used.
- ▸Which languages are used?
- ▸Elm functional language.
- ▸Is it suitable for large projects?
- ▸Yes, for Elm-based web apps.
- ▸Can Elm UI handle responsive design?
- ▸Yes, via flexible box layouts and alignment properties.
30-Day Skill Plan
- ▸Week 1: Simple Box layouts and text elements
- ▸Week 2: Buttons and input fields
- ▸Week 3: Nested composition and reusable components
- ▸Week 4: Responsive design with Elm UI
- ▸Week 5: Full-page web apps and dashboards
Final Summary
- ▸Elm UI is a declarative, type-safe UI library for Elm.
- ▸Uses boxes and elements to build layouts without CSS.
- ▸Ensures predictable and maintainable UI behavior.
- ▸Ideal for Elm projects emphasizing functional, composable design.
- ▸Supports responsive layouts, reusable components, and type-safe styling.
Project Structure
- ▸src/ - Elm modules
- ▸Main.elm - entry point
- ▸UI modules - reusable components
- ▸elm.json - project dependencies
- ▸Assets - images or static files
Monetization
- ▸Internal Elm-based dashboards for enterprises
- ▸Subscription-based Elm web apps
- ▸Educational apps with reusable Elm UI modules
- ▸Component libraries for Elm UI
- ▸Prototyping client apps with rapid iteration
Productivity Tips
- ▸Reuse Box components
- ▸Keep layout logic modular
- ▸Use Elm compiler for type-checking
- ▸Leverage elm-ui documentation examples
- ▸Simplify nested layouts for clarity
Basic Concepts
- ▸Box: fundamental building block for layout
- ▸Layout: determines positioning and alignment
- ▸Element: represents a UI component
- ▸Attributes: apply styling in Elm records
- ▸Composition: nest boxes to build complex UIs