# shinybootstrap2 v0.2.1

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## Bootstrap 2 Web Components for Use with Shiny

Provides Bootstrap 2 web components for use with the Shiny package. With versions of Shiny prior to 0.11, these Bootstrap 2 components were included as part of the package. Later versions of Shiny include Bootstrap 3, so the Bootstrap 2 components have been moved into this package for those uses who rely on features specific to Bootstrap 2.

# shinybootstrap2

This package provides R code and web resources for using Bootstrap 2 with Shiny.

Versions of Shiny up to and including 0.10.2.2 generate HTML that uses Bootstrap 2. With version 0.11, Shiny switched to Bootstrap 3, which is not fully compatible with Bootstrap 2. This package enables backward compatibility for Shiny apps that require Bootstrap 2.

## Quick start

shinybootstrap2 has not yet been released to CRAN, but you can install it using the devtools package.

install.packages('shinybootstrap2')


You can also install the shinyBS2demo package, which demonstrates how to use shinybootstrap2 within a package:

devtools::install_github('rstudio/shinyBS2demo')


## Using shinybootstrap2

There are a number of ways to run a Shiny app: at the console,

### At the console

If you're using Shiny 0.11 or higher, this generates a page using Bootstrap 3 when run at the R console:

library(shiny)

shinyApp(
ui = fluidPage(
sidebarPanel(selectInput("n", "n", c(1, 5, 10))),
mainPanel(plotOutput("plot"))
),
server = function(input, output) {
output$plot <- renderPlot({ plot(head(cars, as.numeric(input$n)))
})
}
)


To use Bootstrap 2, simply wrap your code in shinybootstrap2::withBootstrap2({ }). For example:

shinybootstrap2::withBootstrap2({
shinyApp(
ui = fluidPage(
sidebarPanel(selectInput("n", "n", c(1, 5, 10))),
mainPanel(plotOutput("plot"))
),
server = function(input, output) {
output$plot <- renderPlot({ plot(head(cars, as.numeric(input$n)))
})
}
)
})


You'll notice that the appearance is slightly different. If you inspect the HTML source in your web browser, you'll see that this uses Bootstrap 2, while the previous code uses Bootstrap 3.

Similarly, instead of shinyApp(), you can also wrap calls to runApp() with shinybootstrap2::withBootstrap2().

## In a package

The shinyBS2demo package demonstrates how to use shinybootstrap2 in an R package.

To use shinybootstrap2 components in a package, the DESCRIPTION file should list it in Imports:

Imports:
shinybootstrap2


However, the NAMESPACE should not contain import(shinybootstrap2): this will result in warnings in R CMD check if NAMESPACE also contains import(shiny), because many objects from these two packages have the same name. If you are using roxygen2 for documentation, this means you should not have #' @import shinybootstrap2 in your code.

There are a few different ways you can use shinybootstrap2 in a package:

• Use shinybootstrap2::withBootstrap2().
• Add importFrom(shinybootstrap2,withBootstrap2) to your NAMESPACE file (if you are using roxygen2, you would add #' @importFrom shinybootstrap2 withBootstrap2 to your code), then use withBootstrap2() in your code.

The examples below will use the first method.

### Functions that return a shiny app object

If your package has functions that return a shiny app object (by calling shinyApp()), then you can call shinybootstrap2::withBootstrap2() inside those functions. For example, bs2appObj function in the shinyBS2demo package looks like this:

bs2appObj <- function() {
shinybootstrap2::withBootstrap2({
shinyApp(
ui = fluidPage(
sidebarPanel(selectInput("n", "n", c(1, 5, 10))),
mainPanel(plotOutput("plot"))
),
server = function(input, output) {
output$plot <- renderPlot({ plot(head(cars, as.numeric(input$n)))
})
}
)
})
}


A user of this test package would run it with:

library(shinyBS2demo)
bs2appObj()


You can contrast it to the bs3appObj() function, which doesn't have withBootstrap2() and therefore uses the default Bootstrap 3 components from Shiny:

bs3appObj()


You can view the code for these functions at https://github.com/rstudio/shinyBS2demo/blob/master/R/demo.R.

### Shiny application files

Most Shiny applications consist of a server.R plus ui.R, or, for single file apps, app.R. To use these with shinybootstrap2, simply wrap all the code in shinybootstrap2::withBootstrap2(). The applications in shinyBS2demo's inst/ directory use this format. To run them, you can do:

# Uses shinybootstrap2
runApp(system.file('bs2app', package='shinyBS2demo'))

# Uses Bootstrap 3 components from shiny
runApp(system.file('bs3app', package='shinyBS2demo'))


You can view the code for these apps at https://github.com/rstudio/shinyBS2demo/tree/master/inst/.

To create an app in inst/ like this, the code in ui.R should be wrapped in withBootstrap2():

## ui.R
shinybootstrap2::withBootstrap2({
fluidPage(
selectInput("ui", "Input type", choices = c("numeric", "slider")),
uiOutput("n_ui"),
plotOutput("plot")
)
})


The code in server.R needs withBootstrap2() if it contains dynamic UI-generating code, or code that updates particular types of inputs -- that is, code that is used with renderUI() or updateCheckboxInput(), or updateRadioButtons(). Here's an example server.R to go with the code above:

## server.R
shinybootstrap2::withBootstrap2({
function(input, output) {
output$n_ui <- renderUI({ if (input$ui == "numeric")
numericInput("n", "n", 1)
else if (input$ui == "slider") sliderInput("n", "n", 1, 10, value = 1) }) output$plot <- renderPlot( plot(head(cars, input\$n)) )
}
})


It's safest to simply wrap all server code in shinybootstrap2::withBootstrap2(). If you have global.R, or other files that generate UI code, all the UI-generating code must also be wrapped in shinybootstrap2::withBootstrap2().

For a single-file app, you can simply wrap all the code in shinybootstrap2::withBootstrap2().