R: Conditional CSS styles

styleInterval {DT} | R Documentation

## Conditional CSS styles

### Description

A few helper functions for the `formatStyle()` function to calculate CSS styles for table cells based on the cell values. Under the hood, they just generate JavaScript and CSS code from the values specified in R.

### Usage

    styleInterval(cuts, values)

    styleEqual(levels, values)

    styleColorBar(data, color, angle = 90)

### Arguments

`cuts` | a vector of cut points (sorted increasingly)
`values` | a vector of CSS values
`levels` | a character vector of data values to be mapped (one-to-one) to CSS values
`data` | a numeric vector whose range will be used for scaling the table data from 0-100 before being represented as color bars. A vector of length 2 is acceptable here for specifying a range possibly wider or narrower than the range of the table data itself.
`color` | the color of the bars
`angle` | a number of degrees representing the direction to fill the gradient relative to a horizontal line and the gradient line, going counter-clockwise. For example, 90 fills right to left and -90 fills left to right.

### Details

The function `styleInterval()` maps intervals to CSS values. Its argument `values` must be of length `n + 1` where `n = length(cuts)`. The right-closed interval (cuts[i - 1], cuts[i]] is mapped to values[i] for i = 2, 3, ..., n; values[1] is for the interval (-Inf, cuts[1]], and values[n + 1] is for (cuts[n], +Inf). You can think of the order of `cuts` and `values` using this diagram: -Inf -> values[1] -> cuts[1] -> values[2] -> cuts[2] -> ... -> values[n] -> cuts[n] -> values[n + 1] -> +Inf.

The function `styleEqual()` maps data values to CSS values in the one-to-one manner, i.e. `values[i]` is used when the table cell value is `levels[i]`.

The function `styleColorBar()` can be used to draw background color bars behind table cells in a column, and the width of bars is proportional to the column values.

[Package DT version 0.4 Index]