hf_line: Create a title line container
In pharmaRTF: Enhanced RTF Wrapper for Use with Existing Table Packages

Description Usage Arguments Value Supported Formatting Examples

hf_line objects represent individual title or footnote lines and their associated metadata. These objects are passed to an rtf_doc for display in the header or footer of an RTF document.

A character vector of length <= 2 describes the text to display. Using a single text element, the text can be aligned left, right, or center. Using two text elements, the alignment can be set to “split”, which will left align the first element, and right align the second. If alignment is set to anything else, the text elements will be pasted together.

Lines can either be passed to the titles/footnotes arguments in the call to rtf_doc or added later with the add_titles or add_footnotes functions. Supported properties are detailed in the arguments section.

hf_line(
  ...,
  align = c("center", "left", "right", "split"),
  bold = FALSE,
  italic = FALSE,
  font = NA,
  font_size = NA,
  index = NA
)

`...`	A character list/vector. If `length(...)` is 2 and `align` is not 'split', values are pasted together.
`align`	Text alignment in document. Options are 'center', 'left', 'right', and 'split'. A 'split' alignment will left align the string in the first text item and right align the second. Defaults to center.
`bold`	`TRUE` or `FALSE`. Defaults to FALSE.
`italic`	`TRUE` or `FALSE`. Defaults to FALSE.
`font`	A string to specify the font display. Ensure the intended RTF reader can display the selected font. Fonts for all fields will default to the default font of the `rtf_doc` object, which unless otherwise assigned, is Courier New.
`font_size`	Font size in points. Font sizes for all fields will default to the default font size of the `rtf_doc` object, which unless otherwise assigned, is 12
`index`	Position to display header or footnote lines in the RTF document. Orders in ascending order with NAs last. Defaults to NA.

An object of class hf_line with the properties described in the Arguments section.

Several special display formats are supported to display document data. When the rtf_doc is written, the package will determine if the text of an hf_line object starts with a keyword. Regular expression matching and replacement is used for formatting.

PAGE_FORMAT: - Can take up to two replacements to format current page(first), and total number of pages(second). Page numbers are replaced in the string using %s For example, for a format of Page 1 of 5, use PAGE_FORMAT: Page %s of %s. For a format of just 5, use PAGE_FORMAT: %s.
DATE_FORMAT: - Describes the date/time the document was generated. Formats are specified using standard R date formatting tokens. Details on formatting dates can be found here.
FILE_PATH: - Describes the file path the R session was executed from. The location of the executing file will be populated over the token replacement string "%s". Formats can be specified like "FILE_PATH: Executed from: %s" or simply "FILE_PATH: %s". Note that the location of the executing file in R may not be intuitive. There are multiple ways to determine the containing R file based on how it was executed.
- When the file is executed using Rscript, this field will populated as the executed Rscript file.
- When the file is sourced, this field will populate with the location of the sourced file.
- When a file is run interactively (i.e. from the R console), this field will populate as <run interactively>.

# Adding lines during rtf_doc construction
ht <- huxtable::huxtable(
 column1 = 1:5,
 column2 = letters[1:5]
)
titles_l <- list(
  hf_line(c("The Title Left", "The Titles Right"), align = "split"),
  hf_line("A Bold, italic Title", bold = TRUE, italic = TRUE,
    align = "left", font_size = 20, font = "Times New Roman")
)
rtf <- rtf_doc(ht, titles = titles_l)

# Adding lines after rtf_doc construction
rtf <- add_footnotes(rtf,
    hf_line("PAGE_FORMAT: Page %s of %s"),
    hf_line("DATE_FORMAT: %H:%M %A, %B %d, %Y"),
    hf_line("FILE_PATH: Source: %s")
  )