Return Value

Like many R Shiny modules, the settings widget returns a list of reactives and methods to allow the caller to react to and manipulate settings.

settingsServer return value list

The following values are returned by all instances of the settings widget to allow you to read and modify settings.

# settings_server.R
retval <- reactiveValuesToListOfReactives(settings) # the categorized settings reactives
retval$all_ <- reactive({ allSettings() })
retval$replace <- initializeSettings
retval$cache <- reactive({ cache })
retval$get <- function(tab, id){
    x <- settings[[tab]]
    if(is.null(x)) return(NULL)
    x <- x[[id]]
    if(is.null(x)) return(NULL)
    x$value
}
retval

where each option is accessed in the list as follows (notice that the settings family, i.e., tab, is a reactive function!):

# <module>_server.R
settings <- settingsServer(...)
value <- settings$<familyName>()$<settingName>$value # !! notice the () !!
value <- settings$Plot_Parameters()$X_Axis$value

and additional helper elements are:

• all_ = a reactive to all settings, mainly used for building bookmarks
• replace = a function to replace all settings en bloc in code, mainly used to load bookmarks
• cache = not described here, for advanced use
• get = a convenient, ofter clearer, alternative for retrieving values

thus supporting calls like:

# <module>_server.R
settings <- settingsServer(...)
value <- settings$get("Plot_Parameters", "X_Axis")