example shiny app

library(shiny)
library(purrr)

ui <- fluidPage(
  uiOutput("text_ui")
)

server <- function(input, output) {
  text_list <- c(
    "This is the first line
and this is the second.",
    "Another text string
consisting of two lines."
  )

  format_text <- function(text) {
    text <- stringr::str_replace_all(text, "(\r|\n)", "<br/>")
    shinydashboard::box(text, width = NULL, style = "primary", title = "text box:")
  }

  output$text_ui <- renderUI({
    map(text_list, format_text) %>%
      tagList()
  })
}

shinyApp(ui = ui, server = server)