Serve a local file via HTTP Range Requests from the Shiny session

Registers a local file with the active Shiny session so that igv.js can stream chunks of the file using HTTP 206 Partial Content requests. This allows random-access binary formats (such as BAM, BAI, CRAM, CRAI, BigWig, and Tabix-indexed files) of arbitrary size to be viewed in igvShiny without loading them into R memory or copying them to temporary directories.

Usage

serveLocalFile(session, filePath)

Arguments

session: Shiny session object (must be an active Shiny session)
filePath: character string, path to an existing, readable local file

Value

A character string containing the relative URL to access the file from the browser (e.g. "session/<token>/dataobj/<filename>?...")

Details

The returned URL is relative to the Shiny application root and is routed through the same HTTP port as the Shiny session, ensuring compatibility with Posit Connect, shinyapps.io, reverse proxies, and local development.

Examples

if (FALSE) { # \dontrun{
# Inside a Shiny server function:
server <- function(input, output, session) {
  bam_url <- serveLocalFile(session, "data/sample.bam")
  bai_url <- serveLocalFile(session, "data/sample.bam.bai")

  tracks <- list(
    list(
      name = "Sample BAM",
      type = "alignment",
      format = "bam",
      url = bam_url,
      indexURL = bai_url
    )
  )
  output$igv <- renderIgvShiny({
    igvShiny(genomeOptions, tracks = tracks)
  })
}
} # }