[BUG] Performance: sample selector slow with large number of samples

[anderstorstensson]

Bug Description

The app loads slowly when data folders contain many samples. The console displays warnings suggesting the use of server-side selectize for the sample dropdown.

Steps to Reproduce

Configure the app to use a data folder containing many samples (e.g., 10000+)
Start the app or navigate to a view that loads the sample selector
Observe slow loading times
See warning in R console

Expected Behavior

The app should load quickly regardless of the number of samples, with the sample dropdown remaining responsive.

Actual Behavior

The app takes a long time to load/render, and the following warning appears (twice):

Warning: The select input "sample_select" contains a large number of options; consider using server-side selectize for massively improved performance. See the Details section of the ?selectizeInput help topic.

Environment

R Session Info:

> sessionInfo()
R version 4.5.2 (2025-10-31 ucrt)
Platform: x86_64-w64-mingw32/x64
Running under: Windows Server 2019 x64 (build 17763)

Matrix products: default
  LAPACK version 3.12.1

locale:
[1] LC_COLLATE=English_United States.1252  LC_CTYPE=English_United States.1252    LC_MONETARY=English_United States.1252 LC_NUMERIC=C                          
[5] LC_TIME=English_United States.1252    

time zone: Europe/Berlin
tzcode source: internal

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

other attached packages:
[1] ClassiPyR_0.1.0

loaded via a namespace (and not attached):
 [1] tidyr_1.3.1        sass_0.4.10        generics_0.1.4     class_7.3-23       KernSmooth_2.23-26 stringi_1.8.7      lattice_0.22-7     hms_1.1.4          digest_0.6.38     
[10] magrittr_2.0.4     grid_4.5.2         timechange_0.3.0   RColorBrewer_1.1-3 iRfcb_0.7.0        fastmap_1.2.0      R.oo_1.27.1        jsonlite_2.0.0     Matrix_1.7-4      
[19] zip_2.3.3          R.utils_2.13.0     e1071_1.7-16       DBI_1.2.3          promises_1.5.0     worrms_0.4.3       purrr_1.2.0        scales_1.4.0       jquerylib_0.1.4   
[28] cli_3.6.5          shiny_1.12.1       rlang_1.1.6        units_1.0-0        R.methodsS3_1.8.2  R.matlab_3.7.0     cachem_1.1.0       otel_0.2.0         tools_4.5.2       
[37] tzdb_0.5.0         dplyr_1.1.4        ggplot2_4.0.1      httpuv_1.6.16      DT_0.34.0          curl_7.0.0         reticulate_1.44.1  vctrs_0.6.5        R6_2.6.1          
[46] mime_0.13          png_0.1-8          proxy_0.4-27       classInt_0.4-11    lifecycle_1.0.4    lubridate_1.9.4    stringr_1.6.0      htmlwidgets_1.6.4  shinyjs_2.1.1     
[55] pkgconfig_2.0.3    pillar_1.11.1      bslib_0.10.0       later_1.4.4        gtable_0.3.6       glue_1.8.0         Rcpp_1.1.0         sf_1.0-22          tibble_3.3.0      
[64] tidyselect_1.2.1   rstudioapi_0.17.1  farver_2.1.2       xtable_1.8-4       htmltools_0.5.8.1  readr_2.1.6        compiler_4.5.2     S7_0.2.1 

Operating System:
Windows Server 2019

Browser:
Chrome 144

Error Messages

Warning: The select input "sample_select" contains a large number of options; consider using server-side selectize for massively improved performance. See the Details section of the ?selectizeInput help topic.