R/helpers.R

In AliSaei/HiCSuite: Genome Scaffolding using Hi-C data

# All the code in this file needs to be copied to your Shiny app, and you need
# to call `withBusyIndicatorUI()` and `withBusyIndicatorServer()` in your app.
# You can also include the `appCSS` in your UI, as the example app shows.

# =============================================

# Set up a button to have an animated loading indicator and a checkmark
# for better user experience
# Need to use with the corresponding `withBusyIndicator` server function
withBusyIndicatorUI <- function(button) {
  id <- button[['attribs']][['id']]
  div(
    `data-for-btn` = id,
    button,
    span(
      class = "btn-loading-container",
      shinyjs::hidden(
        img(src = "ajax-loader.gif", class = "btn-loading-indicator", width = '100%', height = '15px')
      )
    ),
    shinyjs::hidden(
      div(class = "btn-err",
          div(icon("exclamation-circle"),
              tags$b("Oops! "),
              span(class = "btn-err-msg")
          )
      )
    )
  )
}

# Call this function from the server with the button id that is clicked and the
# expression to run when the button is clicked
withBusyIndicatorServer <- function(buttonId, expr) {
  # UX stuff: show the "busy" message, hide the other messages, disable the button
  loadingEl <- sprintf("[data-for-btn=%s] .btn-loading-indicator", buttonId)
  errEl <- sprintf("[data-for-btn=%s] .btn-err", buttonId)
  shinyjs::disable(buttonId)
  shinyjs::show(selector = loadingEl)
  shinyjs::hide(selector = errEl)
  on.exit({
    shinyjs::enable(buttonId)
    shinyjs::hide(selector = loadingEl)
  })
  
  # Try to run the code when the button is clicked and show an error message if
  # an error occurs or a success message if it completes
  tryCatch({
    value <- expr
    value
  }, error = function(err) 
    { errorFunc(err, buttonId) }
  )
}

# When an error happens after a button click, show the error
errorFunc <- function(err, buttonId) {
  errEl <- sprintf("[data-for-btn=%s] .btn-err", buttonId)
  errElMsg <- sprintf("[data-for-btn=%s] .btn-err-msg", buttonId)
  errMessage <- gsub("^ddpcr: (.*)", "\\1", err$message)
  shinyjs::html(html = errMessage, selector = errElMsg)
  shinyjs::show(selector = errEl, anim = TRUE, animType = "fade")
}

appCSS <- "
.btn-loading-container {
text-align: center;
margin-top: -20px;
padding: 0px;
font-size: 1.2em;
}
.btn-err {
margin-top: 10px;
color: red;
}
"