Understanding Shiny Action Buttons and Selectize Inputs
==============================================
Introduction
Shiny is a popular R framework for building web applications. In this post, we will explore the issue of action buttons not responding in a shiny app that uses selectize inputs.
The Problem
The question presented involves a shiny app with two selectInput controls: one for selecting years and another for selecting names. Each selectInput should only respond when a specific action button is clicked. However, the first action button (applyNameFilter) does not seem to be responding at all, while the second action button (applyTimeFilter) works fine.
The Code
The provided code snippet demonstrates the shiny app’s UI and server-side logic. It uses shinydashboard, shiny, shinyWidgets, shinyjs, and dplyr libraries.
library(shinydashboard)
library(shiny)
library(shinyWidgets)
library(shinyjs)
library(dplyr)
# Define the data frame
df = data.frame(Name = c('A', 'B', 'C', 'A', 'B', 'C'),
Year = c('2020', '2020', '2020', '2019', '2019', '2019'),
Value = c(12, 33, 44, 55, 22, 11))
# Define the UI
ui <- dashboardPage(
dashboardHeader(title = "Example"),
dashboardSidebar(
sidebarMenu(
menuItem("tab", tabName = "tab", icon = icon("globe"))
)
),
dashboardBody(
useShinyjs(),
tabItems(
tabItem(tabName = "tab",
div(id = 'timeAllFilters',
box(width=12, background = 'green',
selectizeInput(inputId = 'year',
label='Select Year',
choices = c('', '2020', '2019'),
multiple=FALSE,
options = list(
maxItems = 1,
placeholder = '',
onInitialize = I("function() { this.setValue(''); }"))),
actionBttn(inputId = 'applyTimeFilter',
label = "Apply",
style = "gradient",
color = "danger",
icon = icon(""))),
actionBttn(
inputId = 'clearTimeFilter',
label = "Clear",
style = "gradient",
color = "danger",
icon = icon("")))),
div(id = 'nameAllFilters',
dropdown(
tags$h3("Filters"),
selectizeInput(inputId = 'name',
label='Select Name',
choices = c('','A', 'B'),
multiple=FALSE,
options = list(
maxItems = 1,
placeholder = '',
onInitialize = I("function() { this.setValue(''); }"))),
actionBttn(
inputId = 'applyNameFilter',
label = "Apply",
style = "gradient",
color = "danger",
icon = icon(""))),
actionBttn(inputId = 'clearNameFilter',
label = "Clear",
style = "gradient",
color = "danger",
icon = icon("")))`,
dataTableOutput('table')
)
)
)
# Define the server-side logic
server <- function(input, output, session) {
# Create a reactive expression for df1
df1 = reactive({
input$applyTimeFilter
isolate(df %>% filter(Year %in% input$year))
})
# Clear time filters
observeEvent(input$clearTimeFilter, {
reset("timeAllFilters")
})
# Create a reactive expression for df2
df2 = reactive({
input$applyNameFilter
isolate(df1() %>% filter(Name %in% input$name))
})
# Clear name filters
observeEvent(input$clearNameFilter, {
reset("nameAllFilters")
})
output$table = renderDataTable({
DT::datatable(df2())
})
}
# Create the shiny app
shinyApp(ui = ui, server = server)
The Solution
The issue with the first action button (applyNameFilter) not responding is due to its placement inside a box() function. To achieve the same style without using box(), we can use CSS styles.
# Define the UI
ui <- dashboardPage(
dashboardHeader(title = "Example"),
dashboardSidebar(
sidebarMenu(
menuItem("tab", tabName = "tab", icon = icon("globe"))
)
),
dashboardBody(
useShinyjs(),
tabItems(
tabItem(tabName = "tab",
div(id = 'timeAllFilters',
selectizeInput(inputId = 'year',
label='Select Year',
choices = c('', '2020', '2019'),
multiple=FALSE,
options = list(
maxItems = 1,
placeholder = '',
onInitialize = I("function() { this.setValue(''); }"))),
actionBttn(inputId = 'applyTimeFilter',
label = "Apply",
style = "danger gradient",
icon = icon("")))),
actionBttn(
inputId = 'clearTimeFilter',
label = "Clear",
style = "danger gradient",
icon = icon("")),
div(id = 'nameAllFilters',
dropdown(
tags$h3("Filters"),
selectizeInput(inputId = 'name',
label='Select Name',
choices = c('','A', 'B'),
multiple=FALSE,
options = list(
maxItems = 1,
placeholder = '',
onInitialize = I("function() { this.setValue(''); }"))),
actionBttn(
inputId = 'applyNameFilter',
label = "Apply",
style = "danger gradient",
icon = icon(""))),
actionBttn(inputId = 'clearNameFilter',
label = "Clear",
style = "danger gradient",
icon = icon("")))`,
dataTableOutput('table')
)
)
)
By removing the box() function and using CSS styles (style = "danger gradient"), we can achieve the same visual effect without affecting the functionality of the application.
Conclusion
In this post, we explored the issue of action buttons not responding in a shiny app that uses selectize inputs. We found that the first action button (applyNameFilter) was placed inside a box() function, which caused it to not respond. By removing the box() function and using CSS styles, we could achieve the same style without affecting the functionality of the application.
We hope this post has helped you understand how to work with shiny action buttons and selectize inputs in R. If you have any further questions or need additional help, feel free to ask!
Last modified on 2023-06-01