Tab-opening invalidator for custom PTI page layouts

Returns a reactive that emits a fresh `Sys.time()` timestamp the first time the user opens any tab whose name appears in `target_tabs`. Subsequent visits to the same tab do not re-trigger the invalidator. Used by page modules to defer expensive rendering (e.g. the `mod_pti_comparepage_newsrv` map pair) until the tab is actually shown for the first time.

Usage

mod_tab_open_first_newserv(id, active_tab, target_tabs, ...)

Arguments

id

Character. Shiny module namespace ID.

active_tab

Reactive returning the currently selected tab name (typically `reactive(input$tabpan)`). May yield `NULL` for single-tab layouts.

target_tabs

Character vector of tab names whose first-open event should invalidate. May be `NULL` for single-tab layouts.

...

Currently unused; reserved for future extensions.

Value

A reactive returning either `NULL` (before any qualifying tab open) or a `POSIXct` timestamp updated on each first open.

Details

When both `active_tab()` and `target_tabs` are not truthy, the invalidator fires once on init – this covers the single-tab (`launch_pti_onepage`) layout where there is no `navbarPage` selection at all.

See also

Other shiny-modules: mod_dta_explorer2_server(), mod_dta_explorer2_ui(), mod_leaf_side_panel_ui(), mod_map_pti_leaf_ui(), mod_plot_pti2_srv(), mod_pti_comparepage_newsrv(), mod_pti_comparepage_ui(), mod_ptipage_newsrv(), mod_ptipage_twocol_ui()

Examples

if (FALSE) { # \dontrun{
# In a server function:
first_open <- mod_tab_open_first_newserv(
  id          = "first_open",
  active_tab  = reactive(input$tabpan),
  target_tabs = c("PTI", "PTI comparison")
)
observeEvent(first_open(), {
  message("Tab opened for the first time at ", first_open())
})
} # }