myrho

Lightning Talk proposal for ReactiveConf 2017 http://www.reactiveconf.com #ReactiveConf

Porting Prezi to Elm in 99 lines of code

Elm is a statically-typed functional programming language. Its compiler produces safe JavaScript which is guaranteed to be free of runtime exceptions. Moreover Elm is packed with a bunch of powerful abstractions which let us build visual and reactive Web applications in a few lines of code.

As an example, I show the implementation of a simple framework for building Prezi-like presentations. It's just 99 lines of code!

chalmagean

-- Assuming we have a list of items in the model (type alias Model = { items : List Item }
-- where Item is a record like { id : Int, name : String }

-- this goes in the view and generates an html dropdown
select
   [ onSelect ValueSelectedMsg ]
   (List.map (\item -> option [ value (toString item.id) ] [ text item.name ]) model.items)


targetSelectedIndex : Json.Decoder Int

ventsislaf

Note: Don't do this on a production evniroment!

Get the heroku database name:

heroku pg:info

Name can be found in the reponse from the command above. For example: Add-on: soaring-newly-1337.

A5308Y

Documentation:
  Enabled: false
Style/IfUnlessModifier:
  MaxLineLength: 100
Style/WhileUntilModifier:
  MaxLineLength: 100
Style/AlignHash:
  Enabled: false

Metrics/LineLength:

zhengjia

=Navigating=
    visit('/projects')
    visit(post_comments_path(post))

=Clicking links and buttons=
    click_link('id-of-link')
    click_link('Link Text')
    click_button('Save')
    click('Link Text') # Click either a link or a button
    click('Button Value')