addFgb fillColor not working

[DavZim]

When trying to set fillColor in addFgb(), the polygons are not colored...

library(leaflet)
library(leafem)
library(sf)
#> Linking to GEOS 3.8.0, GDAL 3.1.2, PROJ 7.0.0

fgb_file <- tempfile(fileext = ".fgb")
st_write(mapview::franconia, fgb_file)

leaflet() %>% 
  addTiles() %>% 
  leafem::addFgb(fgb_file, fillColor = "red", color = "black", weight = 1) %>% 
  leafem::addMouseCoordinates() %>% 
  setView(10.8, 49.8, 7)

I would expect to see a map like this

# expected
leaflet() %>% 
  addTiles() %>% 
  addPolygons(data = mapview::franconia, fillColor = "red", color = "black", weight = 1)

Ps. Loving the fgb functionality, really helpful for larger datasets!

pps. If fgb_file points to an empty file, the r session crashes (at least in RStudio).

leaflet() %>%
  addFgb(file = "totally-not-existing.fgb")

[tim-salabim]

Thanks! Will look into it shortly.

pps. If fgb_file points to an empty file, the r session crashes (at least in RStudio).

Just to be clear, are you saying that the file does not exist or that it exists but is empty?

[DavZim]

The crash happens if the file does not exist.

Regarding the coloring mapview works.

library(mapview)
#> GDAL version >= 3.1.0 | setting mapviewOptions(fgb = TRUE)
mapview(franconia, col.regions = "red")

But I cant find the color/fill argument in the @map slot.

[tim-salabim]

Yeah, the fillColor is currently written to the fgb file and then used to color the features when rendering. That may be the culprit wh it's not working natively. I'll investigate tonight

[DavZim]

If I can be of any help, let me know!

[tim-salabim]

Thanks for the offer!

This is all pretty alpha still. Long term plan is to supply some sort of colorOptions() containing e.g. the palette definition and breaks or colum name (zcol) and then have the coloring done on render using chroma.js. Would save creating and writing a color vector, but I am not quite sure what these options need to have to cover all cases. It's basically an iterative process with bugs caught in the process... :-)

Do you know any JavaScript?

[DavZim]

Unfortunately I haven't looked into JS yet.

Some colorOptions would be great, especially if it enables to recolor the polygons instead of redrawing them (along the lines of this leaflet issue/solution).

[tim-salabim]

When trying to set fillColor in addFgb(), the polygons are not colored...

This can be solved with setting fill = TRUE. The documentation says

fill whether to fill the path with color (e.g. filling on polygons or circles).

If you have any ideas on how to improve that I'm all ears.
The problem here is that we're using the same function for all types of features without knowing ahead of time what features to expect (unless we'd use gdalinfo or something - which I'd like to avoid). I made the default to be FALSE because in case of linestrings this is the only reasonable choice.

pps. If fgb_file points to an empty file, the r session crashes (at least in RStudio).

I've now included a file.exists call, if FALSE we stop with an error message.

[DavZim]

This closes the issue for me. The not existing file throws an error and doesnt hang the session anymore.

I didn't know I had to set fill=TRUE when fillColors are present, seems kinda unintuitive for me.

Maybe something like addFgb <- function(<...>, fillColor = NULL, fill = !is.null(fillColor), ...) { <...> if (is.null(fillColor)) fillColor = color would help. If fillColor is set, fill is automatically set to TRUE, but if not, the old color argument is still used.
Additionally, mentioning to use fill = TRUE when using fillColor in the documentation would be helpful as well.

Otherwise thank you for the fast fixes!

[tim-salabim]

Thanks, makes sense. We now have default fillColor = NULL. If set, we set fill = TRUE. If fillColor = NULL and fill = TRUE we set fillColor = color.

[tim-salabim]

@DavZim heads-up, I had to revert this, as it messed up things in mapview. I need a bit more time to figure out a proper way of handling this on both sides but am pressed for time a little as I have a mapview course to teach end of August and need this to work from that side. Reopening so I don't forget (hopefully).

[kptitov]

fillColor works when I add a column called fillColor to the .fgb file before passing it to addFgb.
However, I can't seem to pass highlightOptions to leaflet so that the polygons I add with addFgb would behave in the same manner as the ones I can add with the standard leaflet::addPolygons. Would you have any advice on this?
thanks!