I am using the sweet new streams feature to load a timeline of closed pull requests via infinite scroll. It almost works. My streamed objects are not PRs, they are tuples of {<date>, <list of prs>}. Each item in this stream is a section (headered by the date) and within each section is the list of PRs closed on that date.
On first pass my data loads properly. When I trigger the first load of additional data, the new data appears correctly but the PRs from the first batch are gone. The dates and sections still appear, but the sections (ie, list of PRs for that date) are empty.
Am I doing something boneheaded with my state tracking or does LiveView not like these nested lists? Here’s the relevant code:
# changelog_live.ex
def mount(_params, _session, socket) do
if connected?(socket) do
year = Date.utc_today().year
# nb: bucketize/1 function creates the list of {<date>, <list_of_prs>} tuples
pull_requests = Mrgr.PullRequest.socks(current_user, year) |> bucketize()
socket
|> assign(:year, year)
|> stream(:pull_requests, pull_requests, dom_id: &dom_id/1)
|> ok()
end
end
defp dom_id({date, _prs}), do: "week-#{format_week(date)}"
def load_prs(%{assigns: assigns} = socket) do
Mrgr.PullRequest.socks(assigns.current_user, assigns.year)
|> bucketize()
|> Enum.reduce(socket, fn pr, s ->
# `pr` is the tuple
stream_insert(s, :pull_requests, pr)
end)
end
and the template:
# changelog_live.html.heex
<div id="changelog-list-body" phx-update="stream">
<div :for={{dom_id, {date, prs}} <- @streams.pull_requests} id={dom_id}>
<div>
<.h3><%= format_week(date) %></.h3>
<span><%= Enum.count(prs) %></span>
</div>
<.pr_list pull_requests={prs} /><!-- function component that renders list of PRs -->
</div>
</div>
the paging code has been omitted for brevity.
At first I see this, which is correct:
After I scroll down to trigger the stream append, the same area looks like this, which is incorrect:
thoughts?
).
