我有以下示例应用，我需要能够在不破坏应用且隐藏的情况下切换multiple_choice_1_source 或 multiple_choice_2_type的输入当输入发生变化时，submit_request_button_ui和ColnamesInput。基本上，用户应该能够在点击＆＃34;提交＆＃34;之后修改输入。按钮和应用程序应重置为以前的状态。
我尝试过：
shinyjs() - 这只是隐藏而不是清除输入。这意味着，一旦我按下submit_request_button，对multiple_choice_2_type所做的任何更改仍然会被处理并作出反应。在实际的应用程序中，我将提交绑定到非常大的表。我想阻止获取
selected_data()重新运行并清除并隐藏前两个选项中创建的元素。
reactive - 我试图让观察者听一些从多个输入中获取依赖关系的反应式触发器。我使用user_input_rv来存储值等但由于观察者被多次触发而失败，因此当我单击提交按钮时，reactive({})中的if语句被触发两次，主要是下载每个数据集不止一次。它也失败了。
isolate - 我无法完成这项工作。我尝试了多种隔离组合但没有成功。
library(shiny)
library(tidyverse)
ui <- fluidPage(
selectizeInput(inputId ='multiple_choice_1_source',
choices = c("db1","db2","db3","db4"), # like this because we want the selected to be blank on initialisation
label = "1. Select source",
multiple = FALSE,
size = 10,
width = '100%'
)
,uiOutput(outputId="multiple_choice_2_type_ui")
,uiOutput(outputId="submit_request_button_ui")
,uiOutput(outputId="ColnamesInput")
)
server <- function(input, output)
{
user_input_rv = reactiveValues(
source_picked = NULL,
last_used_source = NULL,
type_picked = NULL,
series_picked = NULL,
last_used_series = NULL,
selected_data = NULL,
final_selection = NULL
)
observeEvent(input$multiple_choice_1_source, {
user_input_rv$source_picked <- input$multiple_choice_1_source
#change data loaded under type picked.
user_input_rv$type_picked <-
if ( input$multiple_choice_1_source == "db1"){ paste0(colnames(mtcars))
} else if ( input$multiple_choice_1_source == "db2"){ paste0(colnames(diamonds))
} else if ( input$multiple_choice_1_source == "db3"){ NULL
} else if ( input$multiple_choice_1_source == "db4"){ NULL
}
output$multiple_choice_2_type_ui <- renderUI({
selectizeInput( inputId = 'multiple_choice_2_type',
choices = paste(user_input_rv$type_picked),
label= "2. Select type",
multiple = TRUE,
size = 10,
width = '100%',
options = list( placeholder = 'Type',
maxItems =1
)
)
})
}) #first observeEvent for source type and data load.
observeEvent(input$multiple_choice_2_type,{
output$submit_request_button_ui <- renderUI({
actionButton(
inputId = "submit_request_button",
label = " Get data "
)
})
})#second observeEvent for submit_request_button_ui
observeEvent(input$submit_request_button, {
selected_data <- reactive({
if( input$multiple_choice_1_source =="db1"){
mtcars
} else if ( input$multiple_choice_1_source == "db1") {
diamonds
} else if ( input$multiple_choice_1_source == "db3") { NULL
} else if ( input$multiple_choice_1_source == "db4"){ NULL
}
})
user_input_rv$series_picked <- input$multiple_choice_2_type
user_input_rv$selected_data <- selected_data()
min_cols <- as.integer(1) # default 1
max_cols <- as.integer(length(colnames(selected_data())))
#print(max_cols)
#this renderUI creates the right-hand side column of the app COLUMNS
output$ColnamesInput <- renderUI({
lapply(min_cols:max_cols, function(z) {
column(width = 3,
offset = 0,
selectInput( inputId = paste0("cols","_",z),
label = paste(input$multiple_choice_2_type,": ",colnames(selected_data())[z]),
choices = unique(selected_data()[[z]]),
multiple = TRUE
) #selectizeInput
)
})#lapply inner
}) #renderUI for columns
}) #third observeEvent for data selection and customisation
}
shinyApp(ui = ui, server = server)
答案 0 :(得分：1)
以下是我从中移除reactive expression并使用本地变量selected_data的代码。
observeEvent(input$submit_request_button, {
# selected_data <- reactive({
# browser()
selected_data <- NULL
if( input$multiple_choice_1_source =="db1"){
selected_data <- mtcars
} else if ( input$multiple_choice_1_source == "db1") {
selected_data <- diamonds
} else if ( input$multiple_choice_1_source == "db3") { selected_data <- NULL
} else if ( input$multiple_choice_1_source == "db4"){selected_data <- NULL
}
# })
user_input_rv$series_picked <- isolate(input$multiple_choice_2_type)
user_input_rv$selected_data <- selected_data
min_cols <- as.integer(1) # default 1
max_cols <- as.integer(length(colnames(selected_data)))
#print(max_cols)
#this renderUI creates the right-hand side column of the app COLUMNS
output$ColnamesInput <- renderUI({
lapply(min_cols:max_cols, function(z) {
column(width = 3,
offset = 0,
selectInput( inputId = paste0("cols","_",z),
label = paste(isolate(input$multiple_choice_2_type),": ",colnames(selected_data)[z]),
choices = unique(selected_data[[z]]),
multiple = TRUE
) #selectizeInput
)
})#lapply inner
}) #renderUI for columns
}) #third observeEvent for data selection and customisation
现在，当您更改选择输入选项时，ColnamesInput不会被触发。只有在您单击“提交”按钮后才会触发它。
<强> [编辑]：
可能不是最好的方法，但我认为我能够达到你想要的效果。此外，我已经冒昧地使用已在服务器中定义的reactiveValue。看看下面修改过的服务器代码：
server <- function(input, output)
{
user_input_rv = reactiveValues(
source_picked = NULL,
last_used_source = NULL,
type_picked = NULL,
series_picked = NULL,
last_used_series = NULL,
selected_data = NULL,
final_selection = NULL
)
observeEvent(input$multiple_choice_1_source, {
user_input_rv$source_picked <- input$multiple_choice_1_source
###Start: To check if the source changed#########
if(!is.null(user_input_rv$last_used_source))
{
if(user_input_rv$last_used_source != user_input_rv$source_picked)
{
shinyjs::hide("ColnamesInput")
user_input_rv$last_used_source = user_input_rv$source_picked
}
}else
{
user_input_rv$last_used_source = user_input_rv$source_picked
}
###End: To check if the source changed#########
#change data loaded under type picked.
user_input_rv$type_picked <-
if ( input$multiple_choice_1_source == "db1"){ paste0(colnames(mtcars))
} else if ( input$multiple_choice_1_source == "db2"){ paste0(colnames(diamonds))
} else if ( input$multiple_choice_1_source == "db3"){ NULL
} else if ( input$multiple_choice_1_source == "db4"){ NULL
}
output$multiple_choice_2_type_ui <- renderUI({
selectizeInput( inputId = 'multiple_choice_2_type',
choices = paste(user_input_rv$type_picked),
label= "2. Select type",
multiple = TRUE,
size = 10,
width = '100%',
options = list( placeholder = 'Type',
maxItems =1
)
)
})
}) #first observeEvent for source type and data load.
observeEvent(input$multiple_choice_2_type,{
###Start: To check if the series changed#########
user_input_rv$series_picked <- input$multiple_choice_2_type
if(!is.null(user_input_rv$last_used_series))
{
if(user_input_rv$last_used_series != user_input_rv$series_picked)
{
shinyjs::hide("ColnamesInput")
user_input_rv$last_used_series = user_input_rv$series_picked
}
}else
{
user_input_rv$last_used_series = user_input_rv$series_picked
}
###End: To check if the series changed#########
output$submit_request_button_ui <- renderUI({
actionButton(
inputId = "submit_request_button",
label = " Get data "
)
})
})#second observeEvent for submit_request_button_ui
observeEvent(input$submit_request_button, {
# selected_data <- reactive({
# browser()
shinyjs::show("ColnamesInput")
selected_data <- NULL
if( input$multiple_choice_1_source =="db1"){
selected_data <- mtcars
} else if ( input$multiple_choice_1_source == "db1") {
selected_data <- diamonds
} else if ( input$multiple_choice_1_source == "db3") { selected_data <- NULL
} else if ( input$multiple_choice_1_source == "db4"){selected_data <- NULL
}
# })
user_input_rv$series_picked <- isolate(input$multiple_choice_2_type)
user_input_rv$selected_data <- selected_data
min_cols <- as.integer(1) # default 1
max_cols <- as.integer(length(colnames(selected_data)))
#print(max_cols)
#this renderUI creates the right-hand side column of the app COLUMNS
output$ColnamesInput <- renderUI({
lapply(min_cols:max_cols, function(z) {
column(width = 3,
offset = 0,
selectInput( inputId = paste0("cols","_",z),
label = paste(isolate(input$multiple_choice_2_type),": ",colnames(selected_data)[z]),
choices = unique(selected_data[[z]]),
multiple = TRUE
) #selectizeInput
)
})#lapply inner
}) #renderUI for columns
}) #third observeEvent for data selection and customisation
}
希望它有所帮助！