The cells_title() function is used to target the table title or subtitle
when applying a footnote with tab_footnote() or adding custom style with
tab_style(). The function is expressly used in each of those functions'
locations argument. The header location where the title and optionally the
subtitle reside is generated by the tab_header() function.
cells_title(groups = c("title", "subtitle"))A list object of classes cells_title and location_cells.
We can either specify "title", "subtitle", or both (the
default) in a vector to target the title element, the subtitle element, or
both elements.
Location helper functions can be used to target cells with virtually any
function that has a locations argument. Here is a listing of all of the
location helper functions, with locations corresponding roughly from top to
bottom of a table:
cells_title(): targets the table title or the table subtitle depending on
the value given to the groups argument ("title" or "subtitle").
cells_stubhead(): targets the stubhead location, a cell of which is only
available when there is a stub; a label in that location can be created by
using the tab_stubhead() function.
cells_column_spanners(): targets the spanner column labels with the
spanners argument; spanner column labels appear above the column labels.
cells_column_labels(): targets the column labels with its columns
argument.
cells_row_groups(): targets the row group labels in any available row
groups using the groups argument.
cells_stub(): targets row labels in the table stub using the rows
argument.
cells_body(): targets data cells in the table body using intersections of
columns and rows.
cells_summary(): targets summary cells in the table body using the
groups argument and intersections of columns and rows.
cells_grand_summary(): targets cells of the table's grand summary using
intersections of columns and rows
cells_stub_summary(): targets summary row labels in the table stub using
the groups and rows arguments.
cells_stub_grand_summary(): targets grand summary row labels in the table
stub using the rows argument.
cells_footnotes(): targets all footnotes in the table footer (cannot be
used with tab_footnote()).
cells_source_notes(): targets all source notes in the table footer
(cannot be used with tab_footnote()).
When using any of the location helper functions with an appropriate function
that has a locations argument (e.g., tab_style()), multiple locations
can be targeted by enclosing several cells_*() helper functions in a
list() (e.g., list(cells_body(), cells_grand_summary())).
Use sp500 to create a gt table. Add a header with a title, and then
add a footnote to the title with tab_footnote() and cells_title() (in
locations).
sp500 %>%
dplyr::filter(date >= "2015-01-05" & date <="2015-01-10") %>%
dplyr::select(-c(adj_close, volume, high, low)) %>%
gt() %>%
tab_header(title = "S&P 500") %>%
tab_footnote(
footnote = "All values in USD.",
locations = cells_title(groups = "title")
)

7-5
Other helper functions:
adjust_luminance(),
cell_borders(),
cell_fill(),
cell_text(),
cells_body(),
cells_column_labels(),
cells_column_spanners(),
cells_footnotes(),
cells_grand_summary(),
cells_row_groups(),
cells_source_notes(),
cells_stub_grand_summary(),
cells_stub_summary(),
cells_stubhead(),
cells_stub(),
cells_summary(),
currency(),
default_fonts(),
escape_latex(),
google_font(),
gt_latex_dependencies(),
html(),
md(),
pct(),
px(),
random_id()