EVOLUTION-MANAGER

Edit File: getQueryString.html

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd"><html xmlns="http://www.w3.org/1999/xhtml"><head><title>R: Get the query string / hash component from the URL</title>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<link rel="stylesheet" type="text/css" href="R.css" />
</head><body>

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

<h2>Get the query string / hash component from the URL</h2>

<h3>Description</h3>

<p>Two user friendly wrappers for getting the query string and the hash
component from the app's URL.
</p>

<h3>Usage</h3>

<pre>
getQueryString(session = getDefaultReactiveDomain())

getUrlHash(session = getDefaultReactiveDomain())
</pre>

<h3>Arguments</h3>

<table summary="R argblock">
<tr valign="top"><td><code>session</code></td>
<td>
<p>A Shiny session object.</p>
</td></tr>
</table>

<h3>Details</h3>

<p>These can be particularly useful if you want to display different content
depending on the values in the query string / hash (e.g. instead of basing
the conditional on an input or a calculated reactive, you can base it on the
query string). However, note that, if you're changing the query string / hash
programatically from within the server code, you must use
<code style="white-space: pre;">updateQueryString(_yourNewQueryString_, mode = "push")</code>. The default
<code>mode</code> for <code>updateQueryString</code> is <code>"replace"</code>, which doesn't
raise any events, so any observers or reactives that depend on it will
<em>not</em> get triggered. However, if you're changing the query string / hash
directly by typing directly in the browser and hitting enter, you don't have
to worry about this.
</p>

<h3>Value</h3>

<p>For <code>getQueryString</code>, a named list. For example, the query
string <code>?param1=value1&amp;param2=value2</code> becomes <code>list(param1 = value1, param2 = value2)</code>. For <code>getUrlHash</code>, a character vector with
the hash (including the leading <code style="white-space: pre;">#</code> symbol).
</p>

<p><code><a href="updateQueryString.html">updateQueryString()</a></code>
</p>

<h3>Examples</h3>

<pre>
## Only run this example in interactive R sessions
if (interactive()) {

## App 1: getQueryString
  ## Printing the value of the query string
  ## (Use the back and forward buttons to see how the browser
  ## keeps a record of each state)
  shinyApp(
    ui = fluidPage(
      textInput("txt", "Enter new query string"),
      helpText("Format: ?param1=val1&amp;param2=val2"),
      actionButton("go", "Update"),
      hr(),
      verbatimTextOutput("query")
    ),
    server = function(input, output, session) {
      observeEvent(input$go, {
        updateQueryString(input$txt, mode = "push")
      })
      output$query &lt;- renderText({
        query &lt;- getQueryString()
        queryText &lt;- paste(names(query), query,
                       sep = "=", collapse=", ")
        paste("Your query string is:\n", queryText)
      })
    }
  )

## App 2: 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 &lt;- renderText({
        hash &lt;- getUrlHash()
        paste("Your hash is:\n", hash)
      })
    }
  )
}
</pre>

<hr /><div style="text-align: center;">[Package <em>shiny</em> version 1.5.0 <a href="00Index.html">Index</a>]</div>
</body></html>