Shiny’s grid layout or how to arrange elements side-by-side

The R Shiny framework provides various layout systems to create responsive and flexible user interfaces. One of the most popular layout systems is the grid layout system. In this article, we will discuss the R Shiny grid layout system in detail and provide code examples to demonstrate how it works.

What is the grid layout system in R Shiny?

The grid layout system in R Shiny is a flexible layout system that allows you to arrange UI components in rows and columns. It is similar to the CSS grid layout system, which is commonly used in web development. With the grid layout system, you can create complex and responsive UI designs with ease.

The grid layout system consists of two main components: rows and columns. Rows are used to group UI components together vertically, while columns are used to group UI components together horizontally. You can use the fluidRow and column functions to create rows and columns, respectively.

How to use the grid layout system in R Shiny?

To use the grid layout system in R Shiny, you need to create a UI function that contains one or more rows and columns. Here’s a basic example:

library(shiny)

ui <- fluidPage(
  fluidRow(
    column(width = 3, h1("Column 1")),
    column(width = 3, h1("Column 2")),
    column(width = 3, h1("Column 3")),
    column(width = 3, h1("Column 4"))
  ),
  fluidRow(
    column(width = 3, textInput("text_input", "Text Input")),
    column(width = 1, numericInput("numeric_input", "Numeric Input", value = 0)),
    column(width = 2, selectInput("select_input", "Select Input", choices = c("A", "B", "C"))),
    column(width = 4, checkboxInput("checkbox_input", "Checkbox Input", value = FALSE))
  )
)

server <- function(input, output) {}

shinyApp(ui, server)

In this example, we created a UI function using the fluidPage function. Inside the fluidPage function, we created two fluidRow functions. The first fluidRow contains four column functions, each with a width of 3. The second fluidRow contains four column functions, each with a different width and different input elements.

The width parameter of the column function sets the width of a column as a proportion of the total width of the containing fluidRow. The offset parameter controls how many columns the current column should be offset by. Both width and offset have a maximum value of 12. These parameters are useful for creating responsive and flexible UI layouts that adapt to different screen sizes and devices. By adjusting the width and offset of columns, we can control the placement and proportion of UI elements on the page, making it easier for users to interact with the application.

More complex nested layouts

Nesting fluidRow can be useful in R Shiny for creating more complex UI layouts that require additional levels of organization and structure. By nesting fluidRow inside other fluidRow or column elements, we can create more granular control over the placement of different UI elements on the page. Here is an example:

library(shiny)

ui <- fluidPage(
    
    fluidRow(
        column(
            width = 6,
            sliderInput("slider", "Slider", min = 0, max = 100, value = 50)
        ),
        fluidRow(
            column(
                width = 6,
                checkboxInput("checkbox1", "Checkbox 1", value = TRUE)
            ),
            column(
                width = 6,
                checkboxInput("checkbox2", "Checkbox 2", value = FALSE)
            )
        )
    )
)

server <- function(input, output) {}

shinyApp(ui, server)

Conclusion

The grid layout system in R Shiny is a powerful tool for creating responsive and flexible UI layouts. With the fluidRow and column functions, you can create complex UI designs with ease. By nesting rows and columns, you can create even more complex layouts. The grid layout system is an essential tool for any R Shiny developer who wants to create great-looking and functional web applications.

This post first appeared on rshiny.blog.