R DT rowCallback条件格式化每个单元格

Question

In my DT, I am trying to create conditional formatting for each cell, where formatting is based on different rules for each row. The goal is to create an easy visual comparison between column 1 and column 2

For example

If [1,1] < [1,2] highlight [1,1] green & [1,2] red

If [2,1] < [2,2] highlight [2,1] red & [2,2] green

19 March update : For ease, I built a "winner" column in R, and am trying to compare the data in the table against that column.

library(DT)

example.data <- data.frame(col.1 = rep(1, 2), 
                       col.2 = rep(2, 2), 
                       winner = c(1,2))

datatable(example.data,
      options = list(
        rowCallback = JS(
          'function(nRow, aData, iDisplayIndex, iDisplayIndexFull) {

                            if (parseFloat(aData[3] = 1)){ 
                              $("td:eq(1)", nRow).css("background-color", "green");
                            } 
                            if (parseFloat(aData[3] = 2)){
                              $("td:eq(1)", nRow).css("background-color", "red");
                            }

                            if (parseFloat(aData[3] = 1)){  
                              $("td:eq(2)", nRow).css("background-color", "red");
                            } 
                            if (parseFloat(aData[3] = 2)) {
                              $("td:eq(2)", nRow).css("background-color", "green");
                            }
                          }'
        )
      ))

The above code turns column 1 red and column 2 green. Any help would be appreciated.

Answer 1

The errors in the previous code were due to the misuse of the = operator, should have been ==, and passing the argument as a floating point using parseFloat. For anyone trying to do a similar task, the following example should work.

datatable(example.data,
      options = list(
        rowCallback = JS(
          'function(nRow, aData, iDisplayIndex, iDisplayIndexFull) {

                            if (aData[3] == "1"){ 
                              $("td:eq(1)", nRow).css("background-color", "green");
                            } 
                            if (aData[3] == "2"){
                              $("td:eq(1)", nRow).css("background-color", "red");
                            }

                            if (aData[3] == "1"){  
                              $("td:eq(2)", nRow).css("background-color", "red");
                            } 
                            if (aData[3] == "2") {
                              $("td:eq(2)", nRow).css("background-color", "green");
                            }
                          }'
        )
      ))