form_ "Submit" not responding

[xave]

This is a bit of a tough one, because the issue could be from one of several packages.

• web-inv-route (likely??)
• lucid2 (unlikely)
• htmx-lucid (??)
• network-wai

I create a form like so:

form_
    [hxPost_ "/form", hxTarget_ "#todos", hxSwap_ "beforeend", hxOn_ (HtmxOnEvent AfterRequest) "this.reset()"]
    $ do
        input_ [type_ "text", name_ "msg"]
        input_ [type_ "submit", value_ "Add Todo"]
        div_ [hxGet_ "/todos", hxTrigger_ "load", hxSwap_ "outerHTML"] ""

When I click the submit button, the rendered output is empty (i.e. the string I typed does not show up; empty string).

NOTE: Elements with a "todos" tag are present on page load, so the form should have a valid target. It looks like this:

    todosToUl todos =
          ul_ [id_ "todos"] h
       where
          h = mconcat $ map todoToLi todos :: Html ()

I am using web-inv-route for routing. Those routes look like:

-- curl -X POST localhost:3000/form?msg=fooString
postFormR :: Wai.Request -> RouteAction (String) (IO Wai.Response)
postFormR _req =
    routeMethod GET
        *< routeSecure False
        *< routePath ("form")
        *< routeQuery "msg" parameter
        >* routeHost ("localhost:3000")
        `RouteAction` \(fooString) -> do
            postForm fooString _req

-- curl -X POST localhost:3000/form
postForm2R :: Wai.Request -> RouteAction () (IO Wai.Response)
postForm2R req =
    routeMethod POST
        *< routeSecure False
        *< routePath ("form")
        >* routeHost ("localhost:3000")
        `RouteAction` \() -> do
            let outputString = show req   <----explicitly given string is always added on "submit"
            postForm outputString _req

I have been passing around this req inherited from the app context.

app :: Application
app req resp = ...

The reason for this is that I assumed that I could brute force get my string from the Wai.Request. Yet, logging the request after I hit the submit button does not show the input string anywhere in the Wai.Request record. I cannot think of anywhere else it could be.

Everything works as expected if I curl. It's specifically with the submit button functionality. It should be noted that web-inv-route Request uses a subset of Wai.Request. That's part of why I passed in the Wai.Request to the routes. I'm sure there is a more elegant way to handle that, but I want to get things working first.

[xave]

It was a caching issue (?), it seems. Woke up this morning and everything works.

I did create another app (app2) and ran that. Then I returned back to the one (app) in this referenced post.

Wow! What a ride.

[xave]

When you post to a route like /form as above, there is in fact no data sent to the queryString field. That makes sense.

But the data does go somewhere, of course. As per the docs, you can use either the deprecated Wai.getRequestBody or the recommended Wai.getRequestBodyChunks on the request. However, what you can't do is read the same request twice. Well, you can, but it will only give the correct data the first time.

So if one were to have troubleshooting code that looks like this:

 theReqBody <- BU.toString <$> Wai.requestBody req
 theReqBodyChunk <- BU.toString <$> Wai.getRequestBodyChunk req
 let outputString = theReqBodyChunk <> show req

Whichever of those theReqBody(Chunk) is called second would be empty. And commenting/uncommenting while investigating might lead to the flaky behavior reported above.

In the above snippet, only
let outputString = theReqBody <> show req

would yield all the info.