state updates very rarely) and don't care about maintaining UI state (such as text selection inside that p element)
render it into some container when it is in the same file but not when it is in another file. Or maybe I'm just being stupid here. It is small enough to fit on a screenshot:
I guess it has something to do with the givens and conversions. If I do this in main:
def mainBase: com.raquo.laminar.nodes.ReactiveElement.Base =
mainand render mainBase in the other file, everything works fine
I'm struggling a little with AjaxEventStream... if I provide a valid route, it works!
If my route returns a 400, Bad Request (verified via different tool), then I seem to simply lose the request - I can't figure out how to get any other feedback. I've tried a few variations of the recover block below without success (including a shameless copy paste from the examples)
println(route)
val result = new AjaxEventStream(
route.method.toUpperCase(),
route.route,
upickle.default.write(data),
timeoutMs,
headers,
withCredentials,
responseType,
isStatusCodeSuccess,
requestObserver,
progressObserver,
readyStateChangeObserver
).map(req => {
val t = req.responseText
println(s"Only fires on success : $t")
route.decode(t)
}
).recover { case err: AjaxEventStream.AjaxStreamError => println("recover"); println(err.getMessage); ??? }
result
}The recover block never seems to fire...
I've also tried setting up the request and progress observers (again, copy paste example :-/), but I can't get them to emit anything either... any hints?
@Quafadas: when using ajax event stream, there's an additional param:
isStatusCodeSuccess: Int => Boolean = defaultIsStatusCodeSuccess,so you can tell it which status codes are considered "okay"
by default it's (status >= 200 && status < 300) || status == 304
1 reply
and
def defaultIsStatusCodeSuccess(status: Int): Boolean = {
(status >= 200 && status < 300) || status == 304
}_ => true to collect all the responses and see if that works :)
3 replies
- there are probably bugs to be fixed
- the back-end might eventually fail and require a restart or something; this hasn't happened – but needs some "battle-testing" to be sure
Does renderItemAsTR return a tr(...)? In that case, just use children <-- items.toObservable.split(_.id)(renderItemAsTR).
However, because this is a table, you should wrap all of your rows into thead() and/or tbody(). See https://laminar.dev/documentation#tbody
As a learning exercise, I've set myself the task of prepending a webserver to the "todo" example. Mostly, I think it's working pretty well, but I'm not sure if I'm doing some things which are, effectively anti-patterns.
button(
cls("destroy"),
inContext{
thisNode =>
val $click = thisNode.events(onClick).flatMap {_ => deleteStream(itemId)}
List(
$click.flatMap{_ => RouteApi.simpleRoute(TodoRoutes.listAllTodos)} --> itemsVar.writer
)
}This "button";
- creates an AjaxStream which deletes the thing in question serverside.
- fetches (all) items from the server
- writes the new list into itemsVar - which is effectively the "application state".
With laminar being laminar, everything else does it's "observeable = automagic update thing", and this works.
My questions are;
- The "update" Ajax stream is created, emits once, and is then ( I believe ! ) destroyed. Is this a "reasonable" strategy to create and destroy these streams rather than empty any sort of re-use (is is even possible to force a "single" stream to emit a second time)?
- itemsVar is has effectively no scoping under this mechanism - it's accessed "directly". This sort of makes me shudder... should it? Would it be preferred to
- Pass in it's "writer" as an argument to the method that creates the button?
- Construct some "centralised" updating strategy where the button doesn't update the global state(!)?
- On updating, it replaces the entire contents of the Var. My understanding is that Laminar's "split" operator doesn't care about that - it diffs per element key. There is therefore no difference between "replace entire list with same thing and one element less" and "remove element"? (Aside from network overhead!)
I couldn't figure out how to "hyrdate" the UI on page load ...
val initStream: EventStream[Seq[Todos]] = RouteApi.simpleRoute(TodoRoutes.listAllTodos)
serverStream.foreach(itemsVar.set(_) )(unsafeWindowOwner)The docs appear to indicate that someone at my skill level :-) probably shouldn't be using "unsafe window owner"... as I don't really understand the implications. But the stream needs both an wonder, and something to "listen" to it, otherwise it never fires. I have the feeling this is... a bit wrong(!)?
Any feedback is welcomed...
inContext is not needed I think, try something like composeEvents(onClick)(_ => deleteItem(..).flatMap(_ => reloadAllItems)) --> itemsVar.writer
5 replies
is it possible that at some point you had something like
deleteItem(..).flatMap(_ => reloadAllItems) --> itemsVar.writer(without composeEvents) and it got compiled and hot loaded into the browser while you were adding the composeEvents? :)