web-view-0.4.0: Type-safe HTML and CSS with intuitive layouts and composable styles.
Copyright(c) 2023 Sean Hess
LicenseBSD3
MaintainerSean Hess <seanhess@gmail.com>
Stabilityexperimental
Portabilityportable
Safe HaskellSafe-Inferred
LanguageGHC2021

Web.View

Description

Type-safe HTML and CSS with intuitive layout and composable styles. Inspired by Tailwindcss and Elm-UI

Synopsis

How to use this library

Create styled Views using composable Haskell functions

myView :: View c ()
myView = col (gap 10) $ do
 el (bold . fontSize 32) "My page"
 button (border 1) "Click Me"

This represents an HTML fragment with embedded CSS definitions

<style type='text/css'>
.bold { font-weight:bold }
.brd-1 { border:1px; border-style:solid }
.col { display:flex; flex-direction:column }
.fs-32 { font-size:2.0rem }
.gap-10 { gap:0.625rem }
</style>

<div class='col gap-10'>
  <div class='bold fs-32'>My page</div>
  <button class='brd-1'>Click Me</button>
</div>

Leverage the full power of Haskell functions for reuse, instead of relying on CSS.

header = bold
h1 = header . fontSize 32
h2 = header . fontSize 24
page = gap 10

myView = col page $ do
  el h1 "My Page"
...

This approach is inspired by Tailwindcss' Utility Classes

Rendering Views

renderText :: View () () -> Text Source #

Renders a View as HTML with embedded CSS class definitions

>>> renderText $ el bold "Hello"
<style type='text/css'>.bold { font-weight:bold }</style>
<div class='bold'>Hello</div>

Full HTML Documents

Create a full HTML document by embedding the view and cssResetEmbed

import Data.String.Interpolate (i)
import Web.View

toDocument :: Text -> Text
toDocument content =
  [i|<html>
    <title>My Website</title>
    <head><style type="text/css">#{cssResetEmbed}</style></head>
    <body>#{content}</body>
  </html>|]

myDocument :: Text
myDocument = toDocument $ renderText myView

Views

data View context a Source #

Views are HTML fragments that carry all CSS used by any child element.

view :: View c ()
view = col (pad 10 . gap 10) $ do
  el bold "Hello"
  el_ "World"

They can also have a context which can be used to create type-safe or context-aware elements. See table for an example

Instances

Instances details
Applicative (View context) Source # 
Instance details

Defined in Web.View.View

Methods

pure :: a -> View context a #

(<*>) :: View context (a -> b) -> View context a -> View context b #

liftA2 :: (a -> b -> c) -> View context a -> View context b -> View context c #

(*>) :: View context a -> View context b -> View context b #

(<*) :: View context a -> View context b -> View context a #

Functor (View context) Source # 
Instance details

Defined in Web.View.View

Methods

fmap :: (a -> b) -> View context a -> View context b #

(<$) :: a -> View context b -> View context a #

Monad (View context) Source # 
Instance details

Defined in Web.View.View

Methods

(>>=) :: View context a -> (a -> View context b) -> View context b #

(>>) :: View context a -> View context b -> View context b #

return :: a -> View context a #

IsString (View context ()) Source # 
Instance details

Defined in Web.View.View

Methods

fromString :: String -> View context () #

Mods

type Mod = Attributes -> Attributes Source #

Element functions expect a Mod function as their first argument that adds attributes and classes.

userEmail :: User -> View c ()
userEmail user = input (fontSize 16 . active) (text user.email)
  where
    active = isActive user then bold else id

Elements

el :: Mod -> View c () -> View c () Source #

A basic element

el (bold . pad 10) "Hello"

el_ :: View c () -> View c () Source #

A basic element, with no modifiers

el_ "Hello"

Layout

layout :: Mod -> View c () -> View c () Source #

We can intuitively create layouts with combindations of row, col, grow, and space

Wrap main content in layout to allow the view to consume vertical screen space

holygrail :: View c ()
holygrail = layout id $ do
  row section "Top Bar"
  row grow $ do
    col section "Left Sidebar"
    col (section . grow) "Main Content"
    col section "Right Sidebar"
  row section "Bottom Bar"
  where section = border 1

root :: Mod Source #

As layout but as a Mod

holygrail = col root $ do
  ...

col :: Mod -> View c () -> View c () Source #

Lay out children in a column.

col grow $ do
   el_ "Top"
   space
   el_ "Bottom"

row :: Mod -> View c () -> View c () Source #

Lay out children in a row

row id $ do
   el_ "Left"
   space
   el_ "Right"

grow :: Mod Source #

Grow to fill the available space in the parent row or col

row id $ do
 el grow none
 el_ "Right"

space :: View c () Source #

Space that fills the available space in the parent row or col.

row id $ do
 space
 el_ "Right"

This is equivalent to an empty element with grow

space = el grow none

collapse :: Mod Source #

Allow items to become smaller than their contents. This is not the opposite of grow!

scroll :: Mod Source #

Make a fixed layout by putting scroll on a child-element

document = row root $ do
  nav (width 300) "Sidebar"
  col (grow . scroll) "Main Content"

nav :: Mod -> View c () -> View c () Source #

A Nav element

Content

text :: Text -> View c () Source #

Add text to a view. Not required for string literals

el_ $ do
  "Hello: "
  text user.name

raw :: Text -> View c () Source #

Embed static, unescaped HTML or SVG. Take care not to use raw with user-generated content.

spinner = raw "<svg>...</svg>"

none :: View c () Source #

Do not show any content

if isVisible
 then content
 else none

pre :: Mod -> Text -> View c () Source #

Inputs

form :: Mod -> View c () -> View c () Source #

input :: Mod -> View c () Source #

label :: Mod -> View c () -> View c () Source #

link :: Url -> Mod -> View c () -> View c () Source #

A hyperlink to the given url

button :: Mod -> View c () -> View c () Source #

Tables

table :: Mod -> [dt] -> Eff '[Writer [TableColumn c dt]] () -> View c () Source #

Create a type safe data table by specifying columns

usersTable :: [User] -> View c ()
usersTable us = do
  table id us $ do
    tcol (th hd "Name") $ \u -> td cell $ text u.name
    tcol (th hd "Email") $ \u -> td cell $ text u.email
 where
  hd = cell . bold
  cell = pad 4 . border 1

tcol :: forall dt c. View (TableHead c) () -> (dt -> View dt ()) -> Eff '[Writer [TableColumn c dt]] () Source #

th :: Mod -> View c () -> View (TableHead c) () Source #

td :: Mod -> View () () -> View dt () Source #

data TableColumn c dt Source #

Document Metadata

script :: Text -> View c () Source #

style :: Text -> View c () Source #

CSS Modifiers

width :: Length -> Mod Source #

Set to a specific width

height :: Length -> Mod Source #

Set to a specific height

minWidth :: Length -> Mod Source #

Allow width to grow to contents but not shrink any smaller than value

minHeight :: Length -> Mod Source #

Allow height to grow to contents but not shrink any smaller than value

flexRow :: Mod Source #

Set container to be a row. Favor row when possible

flexCol :: Mod Source #

Set container to be a column. Favor col when possible

pad :: Sides Length -> Mod Source #

Space surrounding the children of the element

To create even spacing around and between all elements:

col (pad 10 . gap 10) $ do
  el_ "one"
  el_ "two"
  el_ "three"

gap :: Length -> Mod Source #

The space between child elements. See pad

hide :: Mod Source #

Hide an element. See parent and media

truncate :: Mod Source #

Cut off the contents of the element

shadow :: Mod Source #

Adds a basic drop shadow to an element

rounded :: Length -> Mod Source #

Round the corners of the element

color :: ToColor c => c -> Mod Source #

Set the text color. See ToColor

bg :: ToColor c => c -> Mod Source #

Set the background color. See ToColor

border :: Sides PxRem -> Mod Source #

Set a border around the element

el (border 1) "all sides"
el (border (X 1)) "only left and right"

borderColor :: ToColor c => c -> Mod Source #

Set a border color. See ToColor

pointer :: Mod Source #

Use a button-like cursor when hovering over the element

Button-like elements:

btn = pointer . bg Primary . hover (bg PrimaryLight)

options = row id $ do
  el btn "Login"
  el btn "Sign Up"

transition :: Ms -> TransitionProperty -> Mod Source #

Animate changes to the given property

el (transition 100 (Height 400)) "Tall"
el (transition 100 (Height 100)) "Small"

Selector States

hover :: Mod -> Mod Source #

Apply when hovering over an element

el (bg Primary . hover (bg PrimaryLight)) "Hover"

active :: Mod -> Mod Source #

Apply when the mouse is pressed down on an element

even :: Mod -> Mod Source #

Apply to even-numbered children

odd :: Mod -> Mod Source #

Apply to odd-numbered children

media :: Media -> Mod -> Mod Source #

Apply when the Media matches the current window. This allows for responsive designs

el (width 100 . media (MinWidth 800) (width 400))
  "Big if window > 800"

parent :: Text -> Mod -> Mod Source #

Apply when the element is somewhere inside an anscestor.

For example, the HTMX library applies an "htmx-request" class to the body when a request is pending. We can use this to create a loading indicator

el (pad 10) $ do
  el (parent "htmx-request" flexRow . hide) "Loading..."
  el (parent "htmx-request" hide . flexRow) "Normal Content"

View Context

context :: View context context Source #

Get the current context

addContext :: context -> View context () -> View c () Source #

Run a view with a specific context in a parent View with a different context. This can be used to create type safe view functions, like table

Creating New Elements and Modifiers

tag :: Text -> Mod -> View c () -> View c () Source #

Create a new element constructor

aside :: Mod -> View c () -> View c ()
aside = tag "aside"

att :: Name -> AttValue -> Mod Source #

Set an attribute, replacing existing value

hlink :: Text -> View c () -> View c ()
hlink url content = tag "a" (att "href" url) content

Types

data Sides a Source #

Options for styles that support specifying various sides. This has a "fake" Num instance to support literals

border 5
border (X 2)
border (TRBL 0 5 0 0)

Constructors

All a 
TRBL a a a a 
X a 
Y a 
XY a a 

Instances

Instances details
Num a => Num (Sides a) Source # 
Instance details

Defined in Web.View.Types

Methods

(+) :: Sides a -> Sides a -> Sides a #

(-) :: Sides a -> Sides a -> Sides a #

(*) :: Sides a -> Sides a -> Sides a #

negate :: Sides a -> Sides a #

abs :: Sides a -> Sides a #

signum :: Sides a -> Sides a #

fromInteger :: Integer -> Sides a #

data Media Source #

Media allows for responsive designs that change based on characteristics of the window. See Layout Example

Constructors

MinWidth Int 
MaxWidth Int 

Instances

Instances details
Eq Media Source # 
Instance details

Defined in Web.View.Types

Methods

(==) :: Media -> Media -> Bool #

(/=) :: Media -> Media -> Bool #

Ord Media Source # 
Instance details

Defined in Web.View.Types

Methods

compare :: Media -> Media -> Ordering #

(<) :: Media -> Media -> Bool #

(<=) :: Media -> Media -> Bool #

(>) :: Media -> Media -> Bool #

(>=) :: Media -> Media -> Bool #

max :: Media -> Media -> Media #

min :: Media -> Media -> Media #

data PxRem Source #

Instances

Instances details
Enum PxRem Source # 
Instance details

Defined in Web.View.Types

Num PxRem Source # 
Instance details

Defined in Web.View.Types

Integral PxRem Source # 
Instance details

Defined in Web.View.Types

Real PxRem Source # 
Instance details

Defined in Web.View.Types

Methods

toRational :: PxRem -> Rational #

Show PxRem Source # 
Instance details

Defined in Web.View.Types

Methods

showsPrec :: Int -> PxRem -> ShowS #

show :: PxRem -> String #

showList :: [PxRem] -> ShowS #

Eq PxRem Source # 
Instance details

Defined in Web.View.Types

Methods

(==) :: PxRem -> PxRem -> Bool #

(/=) :: PxRem -> PxRem -> Bool #

Ord PxRem Source # 
Instance details

Defined in Web.View.Types

Methods

compare :: PxRem -> PxRem -> Ordering #

(<) :: PxRem -> PxRem -> Bool #

(<=) :: PxRem -> PxRem -> Bool #

(>) :: PxRem -> PxRem -> Bool #

(>=) :: PxRem -> PxRem -> Bool #

max :: PxRem -> PxRem -> PxRem #

min :: PxRem -> PxRem -> PxRem #

ToClassName PxRem Source # 
Instance details

Defined in Web.View.Types

ToStyleValue PxRem Source # 
Instance details

Defined in Web.View.Types

data Length Source #

Constructors

PxRem PxRem

Px, converted to Rem. Allows for the user to change the document font size and have the app scale accordingly. But allows the programmer to code in pixels to match a design

Pct Float 

Instances

Instances details
Num Length Source # 
Instance details

Defined in Web.View.Types

Show Length Source # 
Instance details

Defined in Web.View.Types

ToClassName Length Source # 
Instance details

Defined in Web.View.Types

ToStyleValue Length Source # 
Instance details

Defined in Web.View.Types

data TransitionProperty Source #

Constructors

Width PxRem 
Height PxRem 

Instances

Instances details
Show TransitionProperty Source # 
Instance details

Defined in Web.View.Style

data Ms Source #

Milliseconds, used for transitions

Instances

Instances details
Num Ms Source # 
Instance details

Defined in Web.View.Types

Methods

(+) :: Ms -> Ms -> Ms #

(-) :: Ms -> Ms -> Ms #

(*) :: Ms -> Ms -> Ms #

negate :: Ms -> Ms #

abs :: Ms -> Ms #

signum :: Ms -> Ms #

fromInteger :: Integer -> Ms #

Show Ms Source # 
Instance details

Defined in Web.View.Types

Methods

showsPrec :: Int -> Ms -> ShowS #

show :: Ms -> String #

showList :: [Ms] -> ShowS #

ToClassName Ms Source # 
Instance details

Defined in Web.View.Types

Methods

toClassName :: Ms -> Text Source #

ToStyleValue Ms Source # 
Instance details

Defined in Web.View.Types

class ToColor a where Source #

ToColor allows you to create a type containing your application's colors:

data AppColor
  = White
  | Primary
  | Dark

instance ToColor AppColor where
  colorValue White = "#FFF"
  colorValue Dark = "#333"
  colorValue Primary = "#00F"

hello :: View c ()
hello = el (bg Primary . color White) "Hello"

Minimal complete definition

colorValue

Methods

colorValue :: a -> HexColor Source #

colorName :: a -> Text Source #

default colorName :: Show a => a -> Text Source #

Instances

Instances details
ToColor HexColor Source # 
Instance details

Defined in Web.View.Types

newtype HexColor Source #

Hexidecimal Color. Can be specified with or without the leading #. Recommended to use an AppColor type instead of manually using hex colors. See ToColor

Constructors

HexColor Text 

Instances

Instances details
IsString HexColor Source # 
Instance details

Defined in Web.View.Types

ToColor HexColor Source # 
Instance details

Defined in Web.View.Types

ToStyleValue HexColor Source # 
Instance details

Defined in Web.View.Types

data Align Source #

Constructors

Center 

Instances

Instances details
Show Align Source # 
Instance details

Defined in Web.View.Types

Methods

showsPrec :: Int -> Align -> ShowS #

show :: Align -> String #

showList :: [Align] -> ShowS #

ToClassName Align Source # 
Instance details

Defined in Web.View.Types

ToStyleValue Align Source # 
Instance details

Defined in Web.View.Types

Url

type Query = [QueryItem] #

A sequence of QueryItems.