CODEWITHSUNDEEP
rshiny
DJC
DJC

Reputation: 1611

Updating an input and triggering an action button inside an observer

I have an application which utilizes an actionButton to apply a filter selection to a plot. The application also contains a reset actionButton which resets the drop-down selector to its original value, in this instance mpg.

I would like to know whether it is possible to have the reset button not only update the selector itself, but then trigger the apply button so that the plot is reverts back to showing mpg as the y-axis value as it did at initialization.

Please note that the application must utilize the reactiveValues construct shown below as that is present in the actual business use case.

library(shiny)
library(plotly)

ui <- fluidPage(
  ## input and output ui elements and apply/reset buttons
  selectInput("var", "Select Y-Axis Variable", c("mpg", "hp", "wt", "am")),
  actionButton("apply", "Apply"),
  actionButton("reset", "Reset"),
  plotlyOutput("plot")
)

server <- function(input, output, session) {
  ## stored default values
  plot_vals <- reactiveValues(y = "mpg")
  observeEvent(input$apply, {
    plot_vals$y <- input$var
  })
  ## render plot
  output$plot <- renderPlotly(
    mtcars %>% 
      plot_ly(x = ~disp,
              y = ~get(plot_vals$y),
              type = "scatter",
              mode = "markers")
  )
  ## update selectors (how can I have this segment not only update the drop down, but also trigger the apply button?)
  observeEvent(input$reset, {
    updateSelectInput(session = session, "var", selected = "mpg")
  })
}

shinyApp(ui, server)

Upvotes: 2

Views: 168

Answers (1)

ismirsehregal
ismirsehregal

Reputation: 33580

Just update the reactiveVal on reset:

library(shiny)
library(plotly)

ui <- fluidPage(
  ## input and output ui elements and apply/reset buttons
  selectInput("var", "Select Y-Axis Variable", c("mpg", "hp", "wt", "am")),
  actionButton("apply", "Apply"),
  actionButton("reset", "Reset"),
  plotlyOutput("plot")
)

server <- function(input, output, session) {
  ## stored default values
  plot_vals <- reactiveValues(y = "mpg")
  observeEvent(input$apply, {
    plot_vals$y <- input$var
  })
  ## render plot
  output$plot <- renderPlotly({
    mtcars %>% 
      plot_ly(x = ~disp,
              y = ~get(plot_vals$y),
              type = "scatter",
              mode = "markers")
  })
  ## update selectors (how can I have this segment not only update the drop down, but also trigger the apply button?)
  observeEvent(input$reset, {
    updateSelectInput(session = session, "var", selected = "mpg")
    plot_vals$y <- "mpg"
  })
}

shinyApp(ui, server)

Upvotes: 2

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