On flexdashboard, points are invisible until we pan or zoom

[richpauloo]

WegGL points are awesome! Thanks for this amazing functionality.

I noticed some strange behavior in flexdashboard today. Upon load, points are invisible until we pan or zoom. See this SO post for pictures. A regular Rmd html_document doesn't have the same issue, or when saving htmlwidgets::saveWidget(map, "test.html"); browseURL("test.html")).

The code below can be pasted into an Rmd and knit.

---
title: "Untitled"
output: 
  flexdashboard::flex_dashboard:
    orientation: columns
    vertical_layout: fill
---

```{r setup, include=FALSE}
library(flexdashboard)
library(leaflet)
library(leafgl)
library(sf)

n = 100

df1 = data.frame(id = 1:n,
                 x = rnorm(n, 10, 3),
                 y = rnorm(n, 49, 1.8))

pts = st_as_sf(df1, coords = c("x", "y"), crs = 4326)

leaflet() %>%
  addProviderTiles(provider = providers$CartoDB.DarkMatter) %>%
  addGlPoints(data = pts, group = "pts") %>%
  setView(lng = 10.5, lat = 49.5, zoom = 6)
```

Finally, my session info:

> sessionInfo()
R version 4.1.0 (2021-05-18)
Platform: x86_64-apple-darwin17.0 (64-bit)
Running under: macOS Catalina 10.15.7

Matrix products: default
BLAS:   /System/Library/Frameworks/Accelerate.framework/Versions/A/Frameworks/vecLib.framework/Versions/A/libBLAS.dylib
LAPACK: /Library/Frameworks/R.framework/Versions/4.1/Resources/lib/libRlapack.dylib

locale:
[1] en_US.UTF-8/en_US.UTF-8/en_US.UTF-8/C/en_US.UTF-8/en_US.UTF-8

attached base packages:
[1] stats     graphics  grDevices utils    
[5] datasets  methods   base     

other attached packages:
[1] sf_1.0-4            leafgl_0.1.1       
[3] leaflet_2.0.4.1     flexdashboard_0.5.2

loaded via a namespace (and not attached):
 [1] Rcpp_1.0.7         compiler_4.1.0    
 [3] pillar_1.6.4       class_7.3-19      
 [5] tools_4.1.0        digest_0.6.28     
 [7] tibble_3.1.6       jsonlite_1.7.2    
 [9] evaluate_0.14      lifecycle_1.0.1   
[11] pkgconfig_2.0.3    rlang_0.4.12      
[13] DBI_1.1.1          crosstalk_1.2.0   
[15] xfun_0.28          fastmap_1.1.0     
[17] e1071_1.7-9        dplyr_1.0.7       
[19] knitr_1.36         generics_0.1.1    
[21] htmlwidgets_1.5.4  vctrs_0.3.8       
[23] tidyselect_1.1.1   classInt_0.4-3    
[25] grid_4.1.0         glue_1.5.0        
[27] R6_2.5.1           fansi_0.5.0       
[29] rmarkdown_2.11     purrr_0.3.4       
[31] magrittr_2.0.1     htmltools_0.5.2   
[33] ellipsis_0.3.2     units_0.7-2       
[35] assertthat_0.2.1   KernSmooth_2.23-20
[37] utf8_1.2.2         proxy_0.4-26      
[39] crayon_1.4.2 

[tim-salabim]

I'll have a look at this soon. Planning an update of the package to be released to CRAN, so just in time :-)

[richpauloo]

Hey @tim-salabim - I also posted this on StackOverflow and a user suggested using flyTo() to manually zoom (see post here). That seems to fix the issue. The user also suggested the problem is in flexdashboard, but these things are above my current understanding.

[tim-salabim]

Ok, that makes sense somehow, as I was sure that things worked a while ago...