Basic how to package

Jonas Vaclavek

2019-07-31

While developing web applications, CSS is used to style web application’s web pages. The CSS is often written using CSS preprocessor such as SASS or LESS.

rless is a package, which helps to convert LESS files to CSS files within R environment.

This documentation is divided into three sections:

rless functions

parse_less

The parse_less function is a core function of the package. It takes LESS content and converts it to CSS.

convert_file

Passing text into parse_less function is suitable for small chunks. However, for more complex codes, it is more convenient to write LESS file separately and convert the file using convert_file function. It requires two parameters:

The converted file will be stored in tempdir folder or use output_folder argument to set different output location.

The function returns full path to the converted.

convert_folder

When having multiple LESS files, one can use rless function convert_folder. The function requires only input folder to be specified. It goes through the folder and converts all files matching a pattern (*.less by default) into CSS files. tempdir folder is used again as a default output location.

The function allows to specify optional argument:

List of paths to converted files is returned.

LESS

The following sections introduce the basic concepts of LESS with a use of rless function parse_less. More information about LESS features can be found here.

Using in Shiny apps

One of the typical ways of creating web applications in R is using Shiny. This sections shows how easy is to combine it with our rless package.