toHTML: Convert R Objects to HTML

In textutils: Utilities for Handling Strings and Text

Convert R Objects to HTML

Description

Convert an R object to an HTML snippet.

Usage

toHTML(x, ...)

## S3 method for class 'data.frame'
toHTML(x, ...,
                            row.names = FALSE,
                            col.names = TRUE,
                            class.handlers = list(),
                            col.handlers = list(),
                            replace.NA = NULL,
                            td.id = FALSE)

Arguments

x	an object
...	arguments passed to methods
row.names	logical (whether to include row names or not) or string (the column name used for the row-names column)
col.names	logical (whether to include column names or not) or character (specify column names)
class.handlers	a list of named functions. See Examples.
col.handlers	a list of named functions. See Examples.
replace.NA	NULL (do nothing), or a string that replaces all NA values. NA values are noted before any handlers are called.
td.id	logical

Details

There exists toHTML methods in several packages, e.g. in tools or XML. Package R2HTML has a HTML generic.

The ‘semantics’ of this function may differ from other implementations: the function is expected to take an arbitrary R object and return an HTML snippet that can be placed in reports, i.e. the function works in the same spirit as toLatex. By contrast, the purpose of toHTML in tools is to provide a whole HTML document.

The data.frame method has two handlers arguments: these may store helper functions for formatting columns, either of a specific name (col.handlers) or of a specific class(class.handlers). The functions in col.handlers are applied first; and the affected columns are not touched by class.handlers. See Examples.

If td.id is TRUE, all data cells in the table (i.e. td elements) gain an id-attribute of the form td_<row>_<col>.

Value

a character vector

Author(s)

Enrico Schumann

See Also

toLatex

Examples

x <- data.frame(a = 1:3, b = rnorm(3))
cat(toHTML(x,
       col.handlers   = list(b = function(x) round(x, 1)),
       class.handlers = list(integer = function(x) 100*x)))

## [  pretty-printed...  ]
## <tr>   <th>a</th>   <th>b</th> </tr>
## <tr> <td>100</td><td>-2.3</td> </tr>
## <tr> <td>200</td><td>-0.1</td> </tr>
## <tr> <td>300</td><td>-2.8</td> </tr>

textutils documentation built on April 3, 2025, 6:07 p.m.