R: CSS string helper

css {htmltools} | R Documentation

## CSS string helper

### Description

Convenience function for building CSS style declarations (i.e. the string that goes into a style attribute, or the parts that go inside curly braces in a full stylesheet).

### Usage

    css(..., collapse_ = "")

### Arguments

`...` | Named style properties, where the name is the property name and the argument is the property value. See Details for conversion rules.
`collapse_` | (Note that the parameter name has a trailing underscore character.) Character to use to collapse properties into a single string; likely `""` (the default) for style attributes, and either `"\n"` or `NULL` for style blocks.

### Details

CSS uses `'-'` (minus) as a separator character in property names, but this is an inconvenient character to use in an R function argument name. Instead, you can use `'.'` (period) and/or `'_'` (underscore) as separator characters. For example, `css(font.size = "12px")` yields `"font-size:12px;"`.

To mark a property as `!important`, add a `'!'` character to the end of the property name. (Since `'!'` is not normally a character that can be used in an identifier in R, you'll need to put the name in double quotes or backticks.)

Argument values will be converted to strings using `paste(collapse = " ")`. Any property with a value of `NULL` or `""` (after paste) will be dropped.

### Examples

    padding <- 6
    css(
      font.family = "Helvetica, sans-serif",
      margin = paste0(c(10, 20, 10, 20), "px"),
      "padding!" = if (!is.null(padding)) padding
    )

[Package htmltools version 0.5.1.1 Index]