Hi there,

I'm trying to build a Shiny app that utilizes rtracklayer to create custom tracks in the Genome Browser. The code itself is very straightforward - I create a ranges, a track, a session and then call browseGenome.

#Coords is simply a set of coordinates 

targetRanges <- IRanges(coords$start, coords$end)
targetTrack <- with(coords,GRangesForUCSCGenome("hg38", chromosome_name, targetRanges, strand,name, gene))

session <- browserSession("UCSC")

track(session, "custom_1") <- targetTrack

geneRange <- subset(coords,gene==geneName)

grange <- as(paste(geneRange$chromosome_name[1],':',geneRange$start_position[1],'-',geneRange$end_position[1],sep=''),"GRanges")

browseGenome(targetTrack, range = grange,name="custom_1",viewParams=list(full=c("custom_1")))

This is encapsulated in the server portion of my Shiny app. When I run the app locally on my Mac in RStudio, it runs perfectly fine. But when I run it on an Ubuntu 16.04.4 LTS on Shiny Server, it fails with the following error. 

Listening on http://127.0.0.1:33958

/usr/bin/xdg-open: 778: /usr/bin/xdg-open: www-browser: not found
/usr/bin/xdg-open: 778: /usr/bin/xdg-open: links2: not found
/usr/bin/xdg-open: 778: /usr/bin/xdg-open: elinks: not found
/usr/bin/xdg-open: 778: /usr/bin/xdg-open: links: not found
/usr/bin/xdg-open: 778: /usr/bin/xdg-open: lynx: not found
/usr/bin/xdg-open: 778: /usr/bin/xdg-open: w3m: not found
xdg-open: no method available for opening 'http://genome.ucsc.edu/cgi-bin/hgTracks?db=hg38&position=chr1%3a43978943-43991170&ct_cust$

Now, I understand that it is trying to open a new browser window but fails to do so on the server side. What I don't understand is how to direct it to open a client side browser window instead. 

Alternatively, I'm looking into whether I can somehow access the URL that browseGenome generates (with the right hgsid), I can set view=FALSE and create my own link for the client to click on. But after extensively checking and searching, I'm unable to locate the URL in any of the data objects.

Any pointers on accomplishing either of these things would be much appreciated.

Thanks! 

Vivek

> sessionInfo()

R version 3.5.1 (2018-07-02)
Platform: x86_64-pc-linux-gnu (64-bit)
Running under: Ubuntu 16.04.4 LTS

attached base packages:
[1] stats4    parallel  stats     graphics  grDevices utils     datasets  methods   base     

other attached packages:
 [1] seqinr_3.4-5         rtracklayer_1.38.3   GenomicRanges_1.30.3 GenomeInfoDb_1.14.0  IRanges_2.12.0       S4Vectors_0.16.0    
 [7] BiocGenerics_0.24.0  biomaRt_2.37.8       openxlsx_4.1.0       shinyjs_1.0          shiny_1.1.0          tidyr_0.8.1         
[13] gplots_3.0.1         dplyr_0.7.6          epivizrChart_1.3.3  

loaded via a namespace (and not attached):
  [1] backports_1.1.2               Hmisc_4.1-1                   AnnotationHub_2.10.1          plyr_1.8.4                   
  [5] lazyeval_0.2.1                splines_3.5.1                 BiocParallel_1.12.0           ggplot2_3.0.0                
  [9] digest_0.6.17                 BiocInstaller_1.28.0          ensembldb_2.2.2               htmltools_0.3.6              
 [13] gdata_2.18.0                  magrittr_1.5                  checkmate_1.8.5               memoise_1.1.0                
 [17] cluster_2.0.7-1               Biostrings_2.46.0             matrixStats_0.54.0            prettyunits_1.0.2            
 [21] epivizrServer_1.6.0           colorspace_1.3-2              blob_1.1.1                    crayon_1.3.4                 
 [25] RCurl_1.95-4.11               jsonlite_1.5                  graph_1.56.0                  bindr_0.1.1                  
 [29] survival_2.42-6               glue_1.3.0                    gtable_0.2.0                  zlibbioc_1.24.0              
 [33] XVector_0.18.0                DelayedArray_0.4.1            scales_1.0.0                  DBI_1.0.0                    
 [37] Rcpp_0.12.19                  viridisLite_0.3.0             xtable_1.8-3                  progress_1.2.0               
 [41] htmlTable_1.12                foreign_0.8-71                bit_1.1-14                    OrganismDbi_1.20.0           
 [45] Formula_1.2-3                 sqldf_0.4-11                  htmlwidgets_1.3               httr_1.3.1                   
 [49] RColorBrewer_1.1-2            acepack_1.4.1                 pkgconfig_2.0.2               XML_3.98-1.16                
 [53] nnet_7.3-12                   tidyselect_0.2.4              rlang_0.2.2                   later_0.7.5                  
 [57] AnnotationDbi_1.40.0          munsell_0.5.0                 tools_3.5.1                   gsubfn_0.7                   
 [61] RSQLite_2.1.1                 ade4_1.7-13                   stringr_1.3.1                 yaml_2.2.0                   
 [65] knitr_1.20                    bit64_0.9-7                   zip_1.0.0                     caTools_1.17.1.1             
 [69] purrr_0.2.5                   AnnotationFilter_1.2.0        bindrcpp_0.2.2                RBGL_1.54.0                  
 [73] mime_0.5                      compiler_3.5.1                rstudioapi_0.7                curl_3.2                     
 [77] png_0.1-7                     interactiveDisplayBase_1.16.0 tibble_1.4.2                  stringi_1.2.4                
 [81] GenomicFeatures_1.30.3        lattice_0.20-35               ProtGenerics_1.10.0           Matrix_1.2-14                
 [85] pillar_1.3.0                  data.table_1.11.8             bitops_1.0-6                  httpuv_1.4.5.9000            
 [89] R6_2.2.2                      latticeExtra_0.6-28           epivizrData_1.6.0             RMySQL_0.10.15               
 [93] promises_1.0.1                KernSmooth_2.23-15            gridExtra_2.3                 MASS_7.3-50                  
 [97] gtools_3.8.1                  assertthat_0.2.0              chron_2.3-53                  SummarizedExperiment_1.8.1   
[101] proto_1.0.0                   rjson_0.2.20                  withr_2.1.2                   GenomicAlignments_1.14.2     
[105] Rsamtools_1.30.0              GenomeInfoDbData_1.0.0        hms_0.4.2                     grid_3.5.1                   
[109] rpart_4.1-13                  Biobase_2.38.0                base64enc_0.1-3    

Version 1.41.8 supports passing browse=FALSE to browserView() to prevent browsing to the URL. Get the URL from the returned view object with viewURL().