news {utils}R Documentation

Build and Query R or Package News Information

Description

Build and query the news data base for R or add-on packages.

Usage

news(query, package = "R", lib.loc = NULL, format = NULL,
     reader = NULL, db = NULL)

## S3 method for class 'news_db'
print(x, doBrowse = interactive(),
      browser = getOption("browser"), ...)

Arguments

query

an optional expression for selecting news entries.

package

a character string giving the name of an installed add-on package, or "R" or "R-3" or "R-2".

lib.loc

a character vector of directory names of R libraries, or NULL. The default value of NULL corresponds to all libraries currently known.

format

Not yet used.

reader

Not yet used.

db, x

a news db obtained from news().

doBrowse

logical specifying that the news should be opened in the browser (by browseURL, accessible as via help.start) instead of printed to the console.

browser

the browser to be used, see browseURL.

...

potentially further arguments passed to print().

Details

If package is "R" (default), a news db is built with the news since the 4.0.0 release of R, corresponding to the ‘NEWS’ file in the R.home("doc") directory. "R-3" or "R-2" give the news for R 3.x.y or R 2.x.y respectively. Otherwise, if the given add-on package can be found in the given libraries, it is attempted to read its news in structured form from files ‘inst/NEWS.Rd’, ‘NEWS.md’ (since R version 3.6.0, needs packages commonmark and xml2 to be available), ‘NEWS’ or ‘inst/NEWS’ (in that order). See section ‘NEWS Formats’ for the file specifications.

Using query, one can select news entries from the db. If missing or NULL, the complete db is returned. Otherwise, query should be an expression involving (a subset of) the variables Version, Category, Date and Text, and when evaluated within the db returning a logical vector with length the number of entries in the db. The entries for which evaluation gave TRUE are selected. When evaluating, Version and Date are coerced to numeric_version and Date objects, respectively, so that the comparison operators for these classes can be employed.

Value

A data frame inheriting from class "news_db", with character variables Version, Category, Date, Text and HTML, where the last two each contain the entry texts read (in plain-text and HTML format, respectively), and the other variables may be NA if they were missing or could not be determined. The data frame has attributes "package" (and "subset" if the query lead to proper subsetting).

NEWS Formats

inst/NEWS.Rd

File ‘inst/NEWS.Rd’ should be an Rd file given the entries as Rd ⁠\itemize⁠ lists, grouped according to version using ⁠\section⁠ elements. Section titles start with a suitable prefix followed by a space and the version number, and optionally end with a (parenthesized) ISO 8601 (%Y-%m-%d, see strptime) format date (optionally including a note), for example:

    \section{Changes in version 2.0 (2020-02-02, <note>)}{
      \itemize{
        \item ....
      }
    }
  

The entries can be further grouped according to categories using ⁠\subsection⁠ elements named as the categories. The ‘NEWS.Rd’ file is assumed to be UTF-8-encoded (but an included ⁠\encoding⁠ specification takes precedence).

NEWS.md

File ‘NEWS.md’ should contain the news in Markdown (following the CommonMark (https://commonmark.org/) specification), with the primary heading level giving the version number after a prefix followed by a space, and optionally followed by a space and a parenthesized ISO 8601 format date. Where available, secondary headings are taken to indicate categories. To accommodate for common practice, news entries are only split down to the category level.

NEWS

The plain text ‘NEWS’ files in add-on packages use a variety of different formats; the default news reader should be capable to extract individual news entries from a majority of packages from the standard repositories, which use (slight variations of) the following format:

Package tools provides an (internal) utility function news2Rd to convert plain text ‘NEWS’ files to Rd. For ‘NEWS’ files in a format which can successfully be handled by the default reader, package maintainers can use tools:::news2Rd(dir, "NEWS.Rd"), possibly with additional argument codify = TRUE, with dir a character string specifying the path to a package's root directory. Upon success, the ‘NEWS.Rd’ file can further be improved and then be moved to the ‘inst’ subdirectory of the package source directory.

Additional formats and readers may be supported in the future.

Examples

## Build a db of all R news entries.
db <- news()

## Bug fixes with PR number in 4.0.0.
db4 <- news(Version == "4.0.0" & grepl("^BUG", Category) & grepl("PR#", Text),
            db = db)
nrow(db4)

## print db4 to show in an HTML browser.

## News from a date range ('Matrix' is there in a regular R installation):
if(length(iM <- find.package("Matrix", quiet = TRUE)) && nzchar(iM)) {
   dM <- news(package="Matrix")
   stopifnot(identical(dM, news(db=dM)))
   dM2014 <- news("2014-01-01" <= Date & Date <= "2014-12-31", db = dM)
   stopifnot(paste0("1.1-", 2:4) %in% dM2014[,"Version"])
}

## Which categories have been in use? % R-core maybe should standardize a bit more
sort(table(db[, "Category"]), decreasing = TRUE)
## Entries with version >= 4.0.0
table(news(Version >= "4.0.0", db = db)$Version)


## do the same for R 3.x.y, more slowly
db3 <- news(package = "R-3")
sort(table(db3[, "Category"]), decreasing = TRUE)
## Entries with version >= 3.6.0
table(news(Version >= "3.6.0", db = db3)$Version)


[Package utils version 4.4.1 Index]