如何有条件地改变单元格的背景颜色？

Question

我想有条件地将单元格颜色更改为红色（例如 PARAMCD==“Param1”和 AVAL < 0). Is it doable using formatstyle() of DT. I dont want to use custom JS since formatstyle will allow me to easier configure whether I want to process server side or client side with server=TRUE or FALSE. Any suggestion ? I tried below code but getting error.

# Load necessary libraries
library(shiny)
library(DT)

# Define UI
ui <- fluidPage(
  titlePanel("Shiny Testing"),
  sidebarLayout(
    sidebarPanel(
      selectInput("test1", "Select Test 1", choices = NULL),
      selectInput("test2", "Select Test 2", choices = NULL)
    ),
    mainPanel(
      DTOutput("olink")
    )
  )
)

library(dplyr)
library(shiny)
library(DT)


# Define server logic
server <- function(input, output, session) {

  data <- data.frame(
    USUBJID = rep(1:10, each = 5),
    AVISIT = rep(1:5, times = 10),
    PARAMCD = rep(paste0("Param", 1:10), each = 5),
    AVAL = rnorm(50)
  )

  unique_paramcd <- setNames(data$PARAMCD, data$PARAMCD)

  observe({
    updateSelectInput(session, "test1", choices = unique_paramcd)
    updateSelectInput(session, "test2", choices = unique_paramcd)
  })

  # Define a function to preprocess the data and add a new column for background color
  preprocessData <- function(data) {
    data$BackgroundColor <- ifelse(data$PARAMCD == "Param1" & data$AVAL < 0, "red", "white")
    return(data)
  }

  output$olink <- renderDT({
    data <- preprocessData(data)

    datatable(data) %>%
      formatStyle(
        columns = "AVAL",
        valueColumns = "BackgroundColor",
        backgroundColor = styleEqual(c("white", "red"))
      )
  })


}

Answer 1

问题是，作为第一个参数，您必须将唯一值的向量传递给要为其分配颜色的

styleEqual

，并且只有作为第二个参数才应该传递颜色。为了清楚起见，我使用布尔值作为条件。此外，我添加了代码来隐藏具有条件的列。

注意：我删除了闪亮的代码以使示例更加简洁并专注于

DT

。

library(DT)

set.seed(123)

data$BackgroundColor <- data$PARAMCD == "Param1" & data$AVAL < 0

datatable(data,
  options = list(columnDefs = list(list(visible = FALSE, targets = 5)))
) |>
  formatStyle(
    columns = "AVAL",
    valueColumns = "BackgroundColor",
    backgroundColor = styleEqual(
      c(FALSE, TRUE),
      c("white", "red")
    )
  )