Web Application Development with R Using Shiny - Third Edition

Do it yourself

We already saw fluidPage() being used to set up the environment for other layout functions to work. But this function can also be used to build a UI from scratch, using the fluidRow() function. Using fluidRow() within fluidPage() allows you to implement the standard bootstrap grid layout, as described at w3schools.com/bootstrap/bootstrap_grid_system.asp. Essentially, the interface is built up row by row using the fluidRow() function. Each row can be divided into sections of arbitrary width using the column() function. The column function takes a numeric argument specifying how wide it should be. The total of all of these arguments in a given row should always be 12. So, for example, a row might consist of columns of width 3 ...