react-haskell

Haskell React bindings.

This package provides high level bindings to Facebook's React library, meant for use with GHCJS.

React is a JavaScript library for building user interfaces. React (and React-Haskell) is focused on just UI - it's not a framework.

Currently React-Haskell can render simple stateful components, but not what React calls classes. Put another way, React-Haskell doesn't support lifecycle methods yet.

Here's a simple example which demonstrates basic elements, attributes, state, and handling events.

page_ :: ReactNode Void
page_ =
    let cls = smartClass
            -- this is a record and these should really be curly braces,
            -- but haddock breaks on them.
            [ name = "page"

            -- initially the input is empty
            , initialState = ""

            -- always transition to the input's new value
            , transition = \(_, value) -> (value, Nothing)

            , renderFn = \_ str -> div_ [ class_ "container" ] $ do
                input_ [ value_ str, onChange (Just . value . target) ]
            ]
    in classLeaf cls ()

main :: IO ()
main = do
    Just doc <- currentDocument
    Just elem <- documentGetElementById doc ("elem" :: JSString)
    render page_ elem