observe: Select helpers

In yonicd/shinyselect: Observe Multiple Reactive Elements

Description

These functions allow you to observe multiple reactive elements based on their names

Usage

observe_contains(match, handlerExpr, input, ignore.case = TRUE)

observe_starts_with(match, handlerExpr, input, ignore.case = TRUE)

observe_ends_with(match, handlerExpr, input, ignore.case = TRUE)

observe_one_of(elements, handlerExpr, input, ignore.case = TRUE)

Arguments

match	character
handlerExpr	The expression to call whenever eventExpr is invalidated. This should be a side-effect-producing action (the return value will be ignored). It will be executed within an isolate() scope.
input	reactive object to observe
ignore.case	logical If TRUE ignores case when matching names, Default: TRUE
elements	character vector contains names of elements in the reactive object

Details

The internal shiny:observeEvent is passed a variable var_ that contains the matched element name in the reactive object input. That variable can be defined as a paramter of handlerExpr.

Value

observer reference class object

Examples

## Not run: 
if(interactive()){
ui <- shiny::fluidPage(
 shiny::column(width = 6,
               lapply(1:4,FUN = function(x){
                 shiny::textInput(inputId = sprintf('txt_%02d',x),
                                  label = NULL,
                                  value = '',
                                  placeholder = letters[x])
               })),
 shiny::column(width = 6,
               lapply(1:4,FUN = function(x){
                 shiny::actionButton(inputId = sprintf('btn_%02d',x),label = 'update')
               })
               )
)

server <- shiny::shinyServer(function(input, output,session) {

 shinyselect::observe_contains('btn_0(1|3)',
                     handlerExpr = function(var_){
                       shiny::updateTextInput(
                         session,
                         inputId = gsub('btn','txt',var_),
                         value   = strrep(letters[as.numeric(gsub('[^0-9]','',var_))],3)
                         )
                     },input)

 shinyselect::observe_one_of(c('btn_02','btn_04'),
                               handlerExpr = function(var_){
                                 shiny::updateTextInput(
                                   session,
                                   inputId = gsub('btn','txt',var_),
                                   placeholder = 'something new'
                                 )
                               },input)

})

shiny::shinyApp(ui = ui, server = server)
 }

## End(Not run)

yonicd/shinyselect documentation built on Nov. 5, 2019, 1:21 p.m.