EVOLUTION-MANAGER

Edit File: moduleServer.html

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

<h2>Shiny modules</h2>

<h3>Description</h3>

<p>Shiny's module feature lets you break complicated UI and server logic into
smaller, self-contained pieces. Compared to large monolithic Shiny apps,
modules are easier to reuse and easier to reason about. See the article at
<a href="http://shiny.rstudio.com/articles/modules.html">http://shiny.rstudio.com/articles/modules.html</a> to learn more.
</p>

<h3>Usage</h3>

<pre>
moduleServer(id, module, session = getDefaultReactiveDomain())
</pre>

<h3>Arguments</h3>

<table summary="R argblock">
<tr valign="top"><td><code>id</code></td>
<td>
<p>An ID string that corresponds with the ID used to call the module's
UI function.</p>
</td></tr>
<tr valign="top"><td><code>module</code></td>
<td>
<p>A Shiny module server function.</p>
</td></tr>
<tr valign="top"><td><code>session</code></td>
<td>
<p>Session from which to make a child scope (the default should
almost always be used).</p>
</td></tr>
</table>

<h3>Details</h3>

<p>Starting in Shiny 1.5.0, we recommend using <code>moduleServer</code> instead of
<code><a href="callModule.html">callModule()</a></code>, because the syntax is a little easier
to understand, and modules created with <code>moduleServer</code> can be tested with
<code><a href="testServer.html">testServer()</a></code>.
</p>

<h3>Value</h3>

<p>The return value, if any, from executing the module server function
</p>

<p><a href="http://shiny.rstudio.com/articles/modules.html">http://shiny.rstudio.com/articles/modules.html</a>
</p>

<h3>Examples</h3>

<pre>
# Define the UI for a module
counterUI &lt;- function(id, label = "Counter") {
  ns &lt;- NS(id)
  tagList(
    actionButton(ns("button"), label = label),
    verbatimTextOutput(ns("out"))
  )
}

# Define the server logic for a module
counterServer &lt;- function(id) {
  moduleServer(
    id,
    function(input, output, session) {
      count &lt;- reactiveVal(0)
      observeEvent(input$button, {
        count(count() + 1)
      })
      output$out &lt;- renderText({
        count()
      })
      count
    }
  )
}

# Use the module in an app
ui &lt;- fluidPage(
  counterUI("counter1", "Counter #1"),
  counterUI("counter2", "Counter #2")
)
server &lt;- function(input, output, session) {
  counterServer("counter1")
  counterServer("counter2")
}
if (interactive()) {
  shinyApp(ui, server)
}

# If you want to pass extra parameters to the module's server logic, you can
# add them to your function. In this case `prefix` is text that will be
# printed before the count.
counterServer2 &lt;- function(id, prefix = NULL) {
  moduleServer(
    id,
    function(input, output, session) {
      count &lt;- reactiveVal(0)
      observeEvent(input$button, {
        count(count() + 1)
      })
      output$out &lt;- renderText({
        paste0(prefix, count())
      })
      count
    }
  )
}

ui &lt;- fluidPage(
  counterUI("counter", "Counter"),
)
server &lt;- function(input, output, session) {
  counterServer2("counter", "The current count is: ")
}
if (interactive()) {
  shinyApp(ui, server)
}

</pre>

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