EVOLUTION-MANAGER

Edit File: enableBookmarking.html

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<table width="100%" summary="page for enableBookmarking {shiny}"><tr><td>enableBookmarking {shiny}</td><td style="text-align: right;">R Documentation</td></tr></table>

<h2>Enable bookmarking for a Shiny application</h2>

<h3>Description</h3>

<p>There are two types of bookmarking: saving an application's state to disk on
the server, and encoding the application's state in a URL. For state that has
been saved to disk, the state can be restored with the corresponding state
ID. For URL-encoded state, the state of the application is encoded in the
URL, and no server-side storage is needed.
</p>
<p>URL-encoded bookmarking is appropriate for applications where there not many
input values that need to be recorded. Some browsers have a length limit for
URLs of about 2000 characters, and if there are many inputs, the length of
the URL can exceed that limit.
</p>
<p>Saved-on-server bookmarking is appropriate when there are many inputs, or
when the bookmarked state requires storing files.
</p>

<h3>Usage</h3>

<pre>
enableBookmarking(store = c("url", "server", "disable"))
</pre>

<h3>Arguments</h3>

<table summary="R argblock">
<tr valign="top"><td><code>store</code></td>
<td>
<p>Either <code>"url"</code>, which encodes all of the relevant values in
a URL, <code>"server"</code>, which saves to disk on the server, or
<code>"disable"</code>, which disables any previously-enabled bookmarking.</p>
</td></tr>
</table>

<h3>Details</h3>

<p>For restoring state to work properly, the UI must be a function that takes
one argument, <code>request</code>. In most Shiny applications, the UI is not a
function; it might have the form <code>fluidPage(....)</code>. Converting it to a
function is as simple as wrapping it in a function, as in
<code>function(request) { fluidPage(....) }</code>.
</p>
<p>By default, all input values will be bookmarked, except for the values of
passwordInputs. fileInputs will be saved if the state is saved on a server,
but not if the state is encoded in a URL.
</p>
<p>When bookmarking state, arbitrary values can be stored, by passing a function
as the <code>onBookmark</code> argument. That function will be passed a
<code>ShinySaveState</code> object. The <code>values</code> field of the object is a list
which can be manipulated to save extra information. Additionally, if the
state is being saved on the server, and the <code>dir</code> field of that object
can be used to save extra information to files in that directory.
</p>
<p>For saved-to-server state, this is how the state directory is chosen:
</p>

<ul>
<li><p> If running in a hosting environment such as Shiny Server or
Connect, the hosting environment will choose the directory.
</p>
</li>
<li><p> If running an app in a directory with <code><a href="runApp.html">runApp()</a></code>, the
saved states will be saved in a subdirectory of the app called
shiny_bookmarks.
</p>
</li>
<li><p> If running a Shiny app object that is generated from code (not run
from a directory), the saved states will be saved in a subdirectory of
the current working directory called shiny_bookmarks.
</p>
</li></ul>

<p>When used with <code><a href="shinyApp.html">shinyApp()</a></code>, this function must be called before
<code>shinyApp()</code>, or in the <code>shinyApp()</code>'s <code>onStart</code> function. An
alternative to calling the <code>enableBookmarking()</code> function is to use the
<code>enableBookmarking</code> <em>argument</em> for <code>shinyApp()</code>. See examples
below.
</p>

<p><code><a href="onBookmark.html">onBookmark()</a></code>, <code><a href="onBookmark.html">onBookmarked()</a></code>,
<code><a href="onBookmark.html">onRestore()</a></code>, and <code><a href="onBookmark.html">onRestored()</a></code> for registering
callback functions that are invoked when the state is bookmarked or
restored.
</p>
<p>Also see <code><a href="updateQueryString.html">updateQueryString()</a></code>.
</p>

<h3>Examples</h3>

<pre>
## Only run these examples in interactive R sessions
if (interactive()) {

# Basic example with state encoded in URL
ui &lt;- function(request) {
  fluidPage(
    textInput("txt", "Text"),
    checkboxInput("chk", "Checkbox"),
    bookmarkButton()
  )
}
server &lt;- function(input, output, session) { }
enableBookmarking("url")
shinyApp(ui, server)

# An alternative to calling enableBookmarking(): use shinyApp's
# enableBookmarking argument
shinyApp(ui, server, enableBookmarking = "url")

# Same basic example with state saved to disk
enableBookmarking("server")
shinyApp(ui, server)

# Save/restore arbitrary values
ui &lt;- function(req) {
  fluidPage(
    textInput("txt", "Text"),
    checkboxInput("chk", "Checkbox"),
    bookmarkButton(),
    br(),
    textOutput("lastSaved")
  )
}
server &lt;- function(input, output, session) {
  vals &lt;- reactiveValues(savedTime = NULL)
  output$lastSaved &lt;- renderText({
    if (!is.null(vals$savedTime))
      paste("Last saved at", vals$savedTime)
    else
      ""
  })

onBookmark(function(state) {
    vals$savedTime &lt;- Sys.time()
    # state is a mutable reference object, and we can add arbitrary values
    # to it.
    state$values$time &lt;- vals$savedTime
  })
  onRestore(function(state) {
    vals$savedTime &lt;- state$values$time
  })
}
enableBookmarking(store = "url")
shinyApp(ui, server)

# Usable with dynamic UI (set the slider, then change the text input,
# click the bookmark button)
ui &lt;- function(request) {
  fluidPage(
    sliderInput("slider", "Slider", 1, 100, 50),
    uiOutput("ui"),
    bookmarkButton()
  )
}
server &lt;- function(input, output, session) {
  output$ui &lt;- renderUI({
    textInput("txt", "Text", input$slider)
  })
}
enableBookmarking("url")
shinyApp(ui, server)

# Exclude specific inputs (The only input that will be saved in this
# example is chk)
ui &lt;- function(request) {
  fluidPage(
    passwordInput("pw", "Password"), # Passwords are never saved
    sliderInput("slider", "Slider", 1, 100, 50), # Manually excluded below
    checkboxInput("chk", "Checkbox"),
    bookmarkButton()
  )
}
server &lt;- function(input, output, session) {
  setBookmarkExclude("slider")
}
enableBookmarking("url")
shinyApp(ui, server)

# Update the browser's location bar every time an input changes. This should
# not be used with enableBookmarking("server"), because that would create a
# new saved state on disk every time the user changes an input.
ui &lt;- function(req) {
  fluidPage(
    textInput("txt", "Text"),
    checkboxInput("chk", "Checkbox")
  )
}
server &lt;- function(input, output, session) {
  observe({
    # Trigger this observer every time an input changes
    reactiveValuesToList(input)
    session$doBookmark()
  })
  onBookmarked(function(url) {
    updateQueryString(url)
  })
}
enableBookmarking("url")
shinyApp(ui, server)

# Save/restore uploaded files
ui &lt;- function(request) {
  fluidPage(
    sidebarLayout(
      sidebarPanel(
        fileInput("file1", "Choose CSV File", multiple = TRUE,
          accept = c(
            "text/csv",
            "text/comma-separated-values,text/plain",
            ".csv"
          )
        ),
        tags$hr(),
        checkboxInput("header", "Header", TRUE),
        bookmarkButton()
      ),
      mainPanel(
        tableOutput("contents")
      )
    )
  )
}
server &lt;- function(input, output) {
  output$contents &lt;- renderTable({
    inFile &lt;- input$file1
    if (is.null(inFile))
      return(NULL)

if (nrow(inFile) == 1) {
      read.csv(inFile$datapath, header = input$header)
    } else {
      data.frame(x = "multiple files")
    }
  })
}
enableBookmarking("server")
shinyApp(ui, server)

}
</pre>

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