How do I modify the basic counter so in the html file I can define the starting value?

bigos · July 16, 2025, 9:50am

In the counter app there is a HTML fragment that invokes PureScript.
Guide - Halogen Guide

<script src="./index.js" type="module"></script>

How do I modify it so I can configure the initial state in the HTML file and can change the initial state without changing the code of PureScript counter?

bigos · July 16, 2025, 12:17pm

Lucas DiCioccio’s Blog - How I write PureScript web-apps: Part-III

has example

<script
   scr="/js/my-app.js"
   data-my-app--api-endpoint="https://example.com/"
   data-my-app--api-key="0xdeadb33f"
>

this seems to do what I need, but how do I do it in the context of basic halogen counter?

bigos · July 16, 2025, 3:10pm

github.com

bigos/Pyrulis/blob/e91b86c042e473e6d9ec0091db9886a9411385a0/Purescript/halogen/counter/src/App/Counter.purs#L53


      
                          Just a1v -> "a1v"
                      )
                    <> " and "
                    <>
                      ( case a2 of
                          Nothing -> "nic2"
                          Just a2v -> "a2v"
                      )
                )
          
          
readConfig :: Effect String
          readConfig = do
            w <- window
            d <- document w
            script <- currentScript d
            traverse execify script
          
          
counter_color :: Int -> String
          counter_color count =
            if count == 0 then "background: white"
            else (if count < 0 then "background: red" else "background: lime")

I had enough of this nonsense.

I will try flame.

bigos · July 16, 2025, 4:06pm

github.com

bigos/Pyrulis/blob/67fd2aa24bc276c6aa7d554a81a81d364e645cb0/Purescript/flame/counter/src/Main.purs#L103


      
            where
            go script =
              do
                ( TagInsertionConfig
                    <$> getAttribute "data-my-app--api-endpoint" elem
                    <*> getAttribute "data-my-app--api-key" elem
                )
              where
              elem = HTMLScript.toElement script
          
          
main ∷ Effect Unit
          main = do
            w <- window
            config <- readConfig w
            FAE.mount_ (QuerySelector "#flame")
              { init: init :> Just config
              , subscribe: []
              , update
              , view
              }

this is getting closer, but still have errors i do not understand

bigos · July 17, 2025, 7:36pm

I reached the point where I can read the flags, as discussed in other threads.

After a break, I will have to create a working example and maybe ask more questions on improving it.