This starts up the Scotty server. As a tiny example, to display some text saying "hello":

import Purview

view = p [ text "hello" ]

main = run defaultConfiguration { component=view }

This is most straightforward effect handler. It can't send messages to itself or to its parent.

For example, let's say you want to make a button that switches between saying "up" or "down":

view direction = onClick "toggle" $ button [ text direction ]

handler = simpleHandler "up" reduce
  where reduce "toggle" state = if state == "up" then "down" else "up"

component = handler view

More powerful than the simpleHandler, it can send messages to itself or its parent. You will also note that instead of just returning the new state, it returns a function to transform the state. This is because handlers run in their own threads.

This handler gives you access to whichever monad you're running Purview with.

If you wanted to print something on the server every time someone clicked a button:

view direction = onClick "sayHello" $ button [ text "Say hello on the server" ]

handler = effectHandler Nothing reduce
  where reduce "sayHello" state = do
          print "someone on the browser says hello!"
          pure (const Nothing, [])

component = handler view

For adding styles

blue = style "color: \"blue\";"
blueButton = blue $ button [ text "I'm blue" ]

This will send the action to the handler above it whenever "click" is triggered on the frontend. It will be bound to whichever HTML is beneath it.

This will send the action to the handler above it whenever "submit" is triggered on the frontend.

Takes the tree and turns it into HTML. Attributes are passed down to children until they reach a real HTML tag.

Attributes are collected until an HTML constructor is hit, where they are applied during rendering.

This is for creating events that should go to a parent handler, or sent back in to the same handler.

This is what you end up building using the various helpers. It's hopefully rare that you have to use these directly, but it may be useful to better understand what's happening behind the scenes.