Conditional formatting tables in RMarkdown documents

Question

As an example, I might want to use the following rule to color the cells:

(edited to un-trivialize)

1. Blue if > 4
2. No fill if <= 4 and >= 3.5
3. Yellow if >= 3 and < 3.5
4. Orange if < 3

Create tables with conditional formatting with RMarkdown + knitr doesn't help me because I don't just want to highlight cells satisfying one set of criteria.

Example rmd:

---
title: "Untitled"
output: html_document
---

```{r, message = FALSE, results = "asis"}
library(knitr)
library(dplyr)
head(iris) %>% kable
```

I'll take a solution utilizing DataTables if that's what it takes

Answer 1

Hello here a solution using function FlexTable from package ReporteRs. This function is intended to create Word table but you can get the html code from FlexTable objects with as.html :

---
title: "Untitled"
output: html_document
---


```{r, results='asis', warning=FALSE, message=FALSE}
library(ReporteRs)
data(iris)
irisFT = FlexTable( iris )

vars <- c("Sepal.Length", "Sepal.Width", "Petal.Length", "Petal.Width")
for (i in vars) {
  irisFT[iris[, i] < 3, i] = cellProperties( background.color = "orange" )
  irisFT[iris[, i] >= 3 & iris[, i] < 3.5, i] = cellProperties( background.color = "yellow" )
  irisFT[iris[, i] > 4, i] = cellProperties( background.color = "#81DAF5" )
}

cat(as.html(irisFT))
```

For more example, please visit https://davidgohel.github.io/ReporteRs/articles/FlexTable.html

Answer 2

knitr contain vignette with jQuery DataTables example.

vignette("datatables", package = "knitr")