Tabular result display

How a data, parser or transform block previews its result is governed by a tabular display: an S3 object selecting a coherent set of methods for the output container (tabular_ui()), the render function (tabular_output()), the render trigger (tabular_trigger()) and the board options the preview relies on (tabular_options()). Bundling all four on one object keeps them in sync: a display cannot declare a page_size option it then fails to honor, or render through DT while its container is plain text.

Usage

new_tabular_display(subclass)

minimal_display

dt_display

is_tabular_display(x)

tabular_display()

tabular_ui(x, id)

tabular_output(x, result, block, session)

tabular_trigger(x, session)

tabular_options(x, ...)

Arguments

subclass

Display sub-class string

x

Tabular display object

id

Namespace ID for the output container

result

Block result

block

Block object (used to read board option defaults)

session

Shiny session object

...

Forwarded to board option constructors

Value

new_tabular_display() and tabular_display() return a tabular_display object and is_tabular_display() a boolean. tabular_ui() returns shiny UI, tabular_output() the result of a shiny render function, tabular_trigger() is called for its reactive side effect (invisibly returning the option values it depends on) and tabular_options() a board_options set.

Details

The active display is resolved from the blockr.tabular_display option (via blockr_option()) and defaults to minimal_display, a compact preview of the top rows (tibble-formatted when the suggested tibble package is installed, base print() otherwise). dt_display reinstates the paginated, searchable DT table. Downstream packages provide further displays by defining methods for the four generics on their own tabular_display sub-class and having users opt in with options(blockr.tabular_display = <display>).