Should add current URL hash to clientData

[wch]

Currently, clientData only contains the initial URL hash, but it doesn't have the current URL hash. This is because not all browsers at the time supported the onhashchange event. See the comment here:
https://github.com/rstudio/shiny/blob/9613c58/srcjs/init_shiny.js#L412-L416

Pretty much all browsers these days support it, even IE8. See:
http://caniuse.com/#search=onhashchange
http://benalman.com/projects/jquery-hashchange-plugin/

[daattali]

I'm used to the assumption that session$clientData only runs once for each session, when the session begins. Would this be the only case where clientData can get updated during a session? Or was my previous assumption wrong

[wch]

session$clientData is a reactiveValues object. Some of the things don't change, but there are things that do. See here: https://github.com/rstudio/shiny/blob/7aacf9c/R/shiny.R#L206-L212

[bborgesr]

@wch this is about to be merged in the pseudo-nav PR (#1447). Here's the sample app (using the barbara@pushstate branch) -- also in documentation, see ?getUrlHash:

  ## Printing the value of the URL hash
  ## (Use the back and forward buttons to see how the browser
  ## keeps a record of each state)
  shinyApp(
    ui = fluidPage(
      textInput("txt", "Enter new hash"),
      helpText("Format: #hash"),
      actionButton("go", "Update"),
      hr(),
      verbatimTextOutput("hash")
    ),
    server = function(input, output, session) {
      observeEvent(input$go, {
        updateQueryString(input$txt, mode = "push")
      })
      output$hash <- renderText({
        hash <- getUrlHash()
        paste("Your hash is:\n", hash)
      })
    }
  )

What do you think?

[bborgesr]

Closed in #1447 via a0b917a