new_action: Board actions

Description

Logic including a modal-based UI for board actions such as "append block" or "edit stack" can be specified using action objects, which essentially are classed functions that can either be called to return a shiny module as_module = TRUE or a function as_module = FALSE which injects code (passed as expr) into a shiny server context.

Usage

new_action(func)
is_action(x)
is_action_module(x)
is_action_function(x)
add_block_action(trigger, as_module = TRUE)
append_block_action(trigger, as_module = TRUE)
remove_block_action(trigger, as_module = TRUE)
add_link_action(trigger, as_module = TRUE)
remove_link_action(trigger, as_module = TRUE)
add_stack_action(trigger, as_module = TRUE)
edit_stack_action(trigger, as_module = TRUE)
remove_stack_action(trigger, as_module = TRUE)
block_input_select(
  block = NULL,
  block_id = NULL,
  links = NULL,
  mode = c("create", "update", "inputs"),
  ...
)
block_registry_selectize(id, blocks = list_blocks())
board_select(id, blocks, selected = NULL, ...)

Value

The constructor new_action returns a classed function that inherits from action. Inheritance can be checked with functions is_action(), is_action_module() and is_action_function(), which all return scalar logicals.

For utilities block_input_select(), block_registry_selectize()

and board_select, see the respective sections.

Arguments

func: A function which will be evaluated (with modified formals) in a shiny server context
x: Object
trigger: A string, function or shiny::reactive()
as_module: Logical flag controlling the return type
block: Block object
block_id: Block ID
links: Links object
mode: Switch for determining the return object
...: Forwarded to other methods
id: Input ID
blocks: Character vector of block registry IDs
selected: Character vector of pre-selected block (registry) IDs

<code>block_input_select()</code>

Determine input options for a block by removing inputs that are already used and also takes into account some edge-cases, such as variadic blocks. If mode is set as "inputs", this will return a character vector, for "create", the return value of a shiny::selectizeInput() call and for "update", the return value of a shiny::updateSelectizeInput() call.

<code>block_registry_selectize()</code>

This creates UI for a block registry selector via shiny::selectizeInput() and returns an object that inherits from shiny.tag.

<code>board_select()</code>

Block selection UI, enumerating all blocks in a board is available as board_select(). An object that inherits from shiny.tag is returned, which contains the result from a shiny::selectizeInput() call.

Details

An action is a function that can be called with arguments trigger and as_module to return another function. The action trigger may either be a string (referring to an input), a function (that will be called with a single argument input) or a shiny::reactive() object. The flag as_module controls the behavior of the returned function: if TRUE, it is a function (inheriting from action_module) with arguments board, update, ... and domain, which, when called, again returns a function with arguments input, output and session, suitable as argument to shiny::moduleServer(). If FALSE is passed instead, a function (inheriting from action_function) with arguments board, update, ... and domain is returned.

The expression expr, passed when instantiating an action object will be evaluated in a context, where the following bindings exist: board, update, domain, input, output and session. In the case of as_module = FALSE, domain is an alias for session.