Register ggpaintr Server Logic — ptr

Wire the standard ggpaintr server behavior into an existing Shiny app. The returned state object exposes reactive access to the parsed formula, latest runtime result, and current dynamic var UI definitions so callers can extend the app with additional observers and outputs.

Usage

ptr_server(
  input,
  output,
  session,
  formula,
  envir = parent.frame(),
  ui_text = NULL,
  placeholders = NULL,
  ids = ptr_build_ids(),
  expr_check = TRUE
)

Arguments

input: A Shiny input object.
output: A Shiny output object.
session: A Shiny session object.
formula: A single formula string using ggpaintr placeholders.
envir: Environment used to resolve local data objects when building the app.
ui_text: Optional named list of copy overrides for UI labels, helper text, and placeholders.
placeholders: Optional custom placeholder definitions or an existing placeholder registry.
ids: A ptr_build_ids object controlling the Shiny element IDs used by the integration helpers. Defaults to ptr_build_ids().
expr_check: Controls expr placeholder validation. TRUE (default) applies the built-in denylist of dangerous functions. FALSE disables all checking. A named list with deny_list and/or allow_list character vectors supplies a custom check; when both are given, denied entries are removed from the allowlist.

Value

A ptr_state object containing reactive accessors named obj, runtime, and var_ui_list, plus shared metadata used by the bind helpers.