Data module for teal
applications
Source: R/teal_data_module.R
, R/teal_data_module-eval_code.R
, R/teal_data_module-within.R
teal_data_module.Rd
Usage
teal_data_module(ui, server)
# S4 method for teal_data_module,character
eval_code(object, code)
# S3 method for teal_data_module
within(data, expr, ...)
Arguments
- ui
(
function(id)
)shiny
module UI function; must only takeid
argument- server
(
function(id)
)shiny
module server function; must only takeid
argument; must return reactive expression containingteal_data
object- object
(
teal_data_module
)- code
(
character
orlanguage
) code to evaluate. Ifcharacter
, comments are retained.- data
(
teal_data_module
) object- expr
(
expression
) to evaluate. Must be inline code. See- ...
See
Details
.
Value
teal_data_module
returns an object of class teal_data_module
.
eval_code
returns a teal_data_module
object with a delayed evaluation of code
when the module is run.
within
returns a teal_data_module
object with a delayed evaluation of expr
when the module is run.
Details
teal_data_module
creates a shiny
module to supply or modify data in a teal
application.
The module allows for running data pre-processing code (creation and some modification) after the app starts.
The body of the server function will be run in the app rather than in the global environment.
This means it will be run every time the app starts, so use sparingly.
Pass this module instead of a teal_data
object in a call to init()
.
Note that the server function must always return a teal_data
object wrapped in a reactive expression.
See vignette vignette("data-as-shiny-module", package = "teal")
for more details.
eval_code
evaluates given code in the environment of the teal_data
object created by the teal_data_module
.
The code is added to the @code
slot of the teal_data
.
within
is a convenience function for evaluating inline code inside the environment of a teal_data_module
.
It accepts only inline expressions (both simple and compound) and allows for injecting values into expr
through
the ...
argument: as name:value
pairs are passed to ...
, name
in expr
will be replaced with value.
Examples
tdm <- teal_data_module(
ui = function(id) {
ns <- NS(id)
actionButton(ns("submit"), label = "Load data")
},
server = function(id) {
moduleServer(id, function(input, output, session) {
eventReactive(input$submit, {
data <- within(
teal_data(),
{
dataset1 <- iris
dataset2 <- mtcars
}
)
datanames(data) <- c("dataset1", "dataset2")
data
})
})
}
)
eval_code(tdm, "dataset1 <- subset(dataset1, Species == 'virginica')")
#> $ui
#> function(id) {
#> ns <- NS(id)
#> object$ui(ns("mutate_inner"))
#> }
#> <environment: 0x55e360129568>
#>
#> $server
#> function(id) {
#> moduleServer(id, function(input, output, session) {
#> teal_data_rv <- object$server("mutate_inner")
#>
#> if (!is.reactive(teal_data_rv)) {
#> stop("The `teal_data_module` must return a reactive expression.", call. = FALSE)
#> }
#>
#> td <- eventReactive(teal_data_rv(),
#> {
#> if (inherits(teal_data_rv(), c("teal_data", "qenv.error"))) {
#> eval_code(teal_data_rv(), code)
#> } else {
#> teal_data_rv()
#> }
#> },
#> ignoreNULL = FALSE
#> )
#> td
#> })
#> }
#> <environment: 0x55e360129568>
#>
#> attr(,"class")
#> [1] "teal_data_module"
within(tdm, dataset1 <- subset(dataset1, Species == "virginica"))
#> $ui
#> function(id) {
#> ns <- NS(id)
#> object$ui(ns("mutate_inner"))
#> }
#> <environment: 0x55e35e691158>
#>
#> $server
#> function(id) {
#> moduleServer(id, function(input, output, session) {
#> teal_data_rv <- object$server("mutate_inner")
#>
#> if (!is.reactive(teal_data_rv)) {
#> stop("The `teal_data_module` must return a reactive expression.", call. = FALSE)
#> }
#>
#> td <- eventReactive(teal_data_rv(),
#> {
#> if (inherits(teal_data_rv(), c("teal_data", "qenv.error"))) {
#> eval_code(teal_data_rv(), code)
#> } else {
#> teal_data_rv()
#> }
#> },
#> ignoreNULL = FALSE
#> )
#> td
#> })
#> }
#> <environment: 0x55e35e691158>
#>
#> attr(,"class")
#> [1] "teal_data_module"
# use additional parameter for expression value substitution.
valid_species <- "versicolor"
within(tdm, dataset1 <- subset(dataset1, Species %in% species), species = valid_species)
#> $ui
#> function(id) {
#> ns <- NS(id)
#> object$ui(ns("mutate_inner"))
#> }
#> <environment: 0x55e35e41e768>
#>
#> $server
#> function(id) {
#> moduleServer(id, function(input, output, session) {
#> teal_data_rv <- object$server("mutate_inner")
#>
#> if (!is.reactive(teal_data_rv)) {
#> stop("The `teal_data_module` must return a reactive expression.", call. = FALSE)
#> }
#>
#> td <- eventReactive(teal_data_rv(),
#> {
#> if (inherits(teal_data_rv(), c("teal_data", "qenv.error"))) {
#> eval_code(teal_data_rv(), code)
#> } else {
#> teal_data_rv()
#> }
#> },
#> ignoreNULL = FALSE
#> )
#> td
#> })
#> }
#> <environment: 0x55e35e41e768>
#>
#> attr(,"class")
#> [1] "teal_data_module"