Bslib-Themed App: A Demonstration Wrapper

A small wrapper that composes the public ggpaintr primitives (ptr_ui_controls(), ptr_ui_plot(), ptr_ui_toggle_code(), ptr_server()) inside a bslib::page_sidebar() shell. Exported so users who want a quick bslib-themed app can call it directly, but its primary purpose is to illustrate the wrapper pattern: the entire source is short enough to copy and adapt for any other layout or theme.

Usage

ptr_app_bslib(
  formula,
  envir = parent.frame(),
  ui_text = NULL,
  expr_check = TRUE,
  safe_to_remove = character(),
  theme = NULL,
  spec = NULL
)

Arguments

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. The app title is read from ui_text$shell$title$label; defaults to "ggpaintr".

expr_check

Controls formula-level ppExpr validation: TRUE (default) applies the built-in denylist + AST walker; FALSE disables formula-level validation; a list with deny_list/allow_list entries customises the formula-level policy. Runtime-typed ppExpr input is always screened against the built-in denylist regardless. See the safety chapter of the ggpaintr book (development-version docs): https://willju-wangqian.github.io/ggpaintr-book/safety.html.

safe_to_remove

Character vector of additional function names whose zero-argument calls should be dropped after placeholder substitution leaves them empty. Defaults to character().

theme

A bslib theme object. Defaults to a Bootstrap 5 Flatly bootswatch. Pass any bslib::bs_theme() result to customize. This is a bslib passthrough and is not part of the ggpaintr public surface the wrapper demonstrates — wrappers are free to expose downstream-library args like this in addition to whatever ggpaintr primitives they compose.

spec

An optional named list of fully-qualified Shiny input id -> value, used to override widget defaults at session boot.

For the formula grammar (placeholder keywords, shared annotation, empty-call cleanup), see ptr_app().

Value

A shiny.appobj.

Details

For the recommended primary entry points, see ptr_app() and ptr_app_grid(). Requires the bslib package (install.packages("bslib")).

Single-formula ppVar(shared = "...") coordination is not supported on this wrapper — the auto-built shared widgets ptr_app() provides require an internal helper that is not part of the public API today. Use ptr_app() for that case, or ptr_app_grid() for multi-formula shared coordination (the shared widgets auto-render from each placeholder's own build_ui).