teal.slice (version 0.5.1)

init_filter_state: Initialize FilterState

Description

Initializes a FilterState object corresponding to the class of the filtered variable.

Usage

init_filter_state(
  x,
  x_reactive = reactive(NULL),
  slice,
  extract_type = character(0)
)

Value

FilterState object

Arguments

x

(vector) variable to be filtered.

x_reactive

(reactive) returning vector of the same type as x. Is used to update counts following the change in values of the filtered dataset. If it is set to reactive(NULL) then counts based on filtered dataset are not shown.

slice

(teal_slice) specification of this filter state. teal_slice is stored in the object and set_state directly manipulates values within teal_slice. get_state returns teal_slice object which can be reused in other places. Note that teal_slice is a reactiveValues, which means it has reference semantics, i.e. changes made to an object are automatically reflected in all places that refer to the same teal_slice.

extract_type

(character) specifying whether condition calls should be prefixed by dataname. Possible values:

• character(0) (default) varname in the condition call will not be prefixed

• "list" varname in the condition call will be returned as <dataname>$<varname>

• "matrix" varname in the condition call will be returned as <dataname>[, <varname>]

Examples

# use non-exported function from teal.slice
init_filter_state <- getFromNamespace("init_filter_state", "teal.slice")

library(shiny)

filter_state <- init_filter_state(
  x = c(1:10, NA, Inf),
  x_reactive = reactive(c(1:10, NA, Inf)),
  slice = teal_slice(
    varname = "varname",
    dataname = "dataname"
  ),
  extract_type = "matrix"
)

isolate(filter_state$get_call())

# working filter in an app

ui <- fluidPage(
  filter_state$ui(id = "app"),
  verbatimTextOutput("call")
)
server <- function(input, output, session) {
  filter_state$server("app")

  output$call <- renderText(
    deparse1(filter_state$get_call(), collapse = "\n")
  )
}

if (interactive()) {
  shinyApp(ui, server)
}