scattermapbox non-circle marker symbols not shown in legend since v4.12.0

Iniziare con il reprex R fornito usando trace scattermapbox e confrontare il comportamento della legenda tra plotly 4.11.0 e 4.12.0. Tracciare il modo in cui i simboli dei marker vengono passati tramite add_trace e ispezionare la gestione della legenda di scattermapbox; il lavoro è completo quando le voci circle, diamond, square e marker vengono visualizzate correttamente senza influire sul comportamento di scattergeo o scatter.

Since upgrading to plotly 4.12.0, only the "circle" symbol is rendered correctly in the legend for scattermapbox traces. Other marker symbols (e.g. "diamond", "square") are no longer displayed — the legend shows a blank entry for those.

v 4.12.0

v 4.11.0

(note that already in previuos versions, the non-circle markers were not shown on the canvas itself, but this was not an issue in our use case, because we only wanted to create the custom legend with the square markers)

reprex

library(plotly)

symbols_to_try <- c(
  "circle",
  "diamond",
  "square",
  "marker"
)

traces <- lapply(seq_along(symbols_to_try), function(i) {
  list(
    type       = "scattermapbox",
    mode       = "markers",
    lon        = i * 2,
    lat        = 51,
    name       = symbols_to_try[i],
    showlegend = TRUE,
    hoverinfo  = "name",
    marker     = list(
      color  = "steelblue",
      size   = 20,
      symbol = symbols_to_try[i]
    )
  )
})

p <- plotly_empty() |>
  layout(
    mapbox = list(
      style  = "carto-positron",
      center = list(lon = 5, lat = 51),
      zoom   = 3
    ),
    legend = list(x = 1, xanchor = "right", y = 1)
  ) |>
  config(displaylogo = FALSE)

for (tr in traces) {
  p <- add_trace(p,
    inherit    = FALSE,
    type       = tr$type,
    mode       = tr$mode,
    lon        = tr$lon,
    lat        = tr$lat,
    name       = tr$name,
    showlegend = tr$showlegend,
    hoverinfo  = tr$hoverinfo,
    marker     = tr$marker
  )
}

p

packageVersion("plotly")

Further info:

The legend (and markers on canvas) work fine with "scattergeo" or even "scatter", but it has other side-effects in our setting that makes the plot be drawn twice, even if setting the layout like

plotly::layout(
    plotly_object,
    geo = list(
      visible = FALSE,
      showframe = FALSE,
      showcoastlines = FALSE,
      showland = FALSE,
      showocean = FALSE
    )
  )