将两个不同的操作按钮链接到呈现的表格时遇到问题。每当用户启用"保存群组"操作按钮时，数据集都会正确保存，并且输出表"cohort_names"更新即可。但是，当我"重置同类群组"时，"保存的同类群组"名称表不会为空。在下面的示例代码中，我引用了相同的假数据集。
shinyServer(function(input, output, session) {
populations = reactiveValues(a = 0)
values = reactiveValues(extracted_data = NULL)
#This finds a dataframe to be saved
observeEvent(input$run_query, {
values$extracted_data = data.frame(id = c(153, 343, 996), sex = c(2,1,1)) #Just an example. Behind the scenes I am running an SQL query
})
#This action button saves a data frame to a reactive list
observeEvent(input$save_cohort, {
if(!is.null(values$extracted_data) & input$name_cohort != "a") {
populations$a = populations$a + 1
cname = ifelse(input$name_cohort == "", paste("Population", populations$a), input$name_cohort)
populations[[cname]] = values$extracted_data #This object comes from a "run query" action and works just fine
print(populations$a)
}
})
#This action button is suppose to reset the reactive object "populations" to NULL and resets the counter (a)
observeEvent(input$reset_cohorts, {
populations = NULL
populations$a = 0
print(populations$a)
})
#Population info
output$populations = renderText(populations$a)
updated_names <- reactive({
tmpnames = cbind(names(populations)[-which(names(populations) == "a")])
colnames(tmpnames) = "Populations"
print(tmpnames)
tmpnames
})
#This is what is NOT updating. I need cohort_names to reset to nothing when reset_cohorts is enabled. It updates JUST FINE when save_cohorts is enabled.
output$cohort_names = renderTable({updated_names()}, align = 'c', width = "100%")
}
这是一个简单的 ui.r，以防有人想要重新创建：
shinyUI(fluidPage(
sidebarLayout(
sidebarPanel(tableOutput("cohort_names")),
mainPanel(actionButton("run_query", "Run Query"),
actionButton("save_cohort", "Save Cohort"),
actionButton("reset_cohorts", "Reset Cohorts"),
textInputRow("name_cohort",label= NULL, placeholder = "Enter Cohort Name"))
)
)
我目前的运行理论是我错误地对待反应式值，但我一生都无法找到合适的解决方案。任何建议将不胜感激
虽然我可以实现你想要的，但我的代码有一个错误。如果首次按重置同类群组按钮，它会在后台重置所有内容(请参阅控制台打印(，但 UI 不会显示更新的值。第二次单击重置群组按钮，一切都按预期工作。无法弄清楚为什么会发生这种情况:(
这是代码，以防您可以忍受该错误。
library(shiny)
server <- function(input, output, session) {
populations <<- list()
pop_counter <- reactiveValues(a = 0)
values <- reactiveValues(extracted_data = NULL)
#This finds a dataframe to be saved
observeEvent(input$run_query, {
values$extracted_data = data.frame(id = c(153, 343, 996), sex = c(2,1,1)) #Just an example. Behind the scenes I am running an SQL query
})
#This action button saves a data frame to a reactive list
observeEvent(input$save_cohort, {
if(!is.null(values$extracted_data) & input$name_cohort != "a") {
pop_counter$a = pop_counter$a + 1
cname = ifelse(input$name_cohort == "", paste("Population", pop_counter$a), input$name_cohort)
populations[[cname]] <<- values$extracted_data #This object comes from a "run query" action and works just fine
print('inside saving cohort....')
print(populations)
print(class(populations))
print(pop_counter$a)
}
})
#This action button is suppose to reset the reactive object "populations" to NULL and resets the counter (a)
observeEvent(input$reset_cohorts, {
print('inside resetting of populations list')
populations <<- list()
pop_counter$a <- 0
print(populations)
print(pop_counter$a)
})
updated_names <- eventReactive(c(input$reset_cohorts, input$save_cohort),{
print('inside updated_names() ...')
if(length(populations) == 0) return(data.frame())
tmpnames <- cbind(names(populations))#[-which(names(populations) == "a")]
colnames(tmpnames) = "Populations"
print(tmpnames)
tmpnames
})
#This is what is NOT updating. I need cohort_names to reset to nothing when reset_cohorts is enabled. It updates JUST FINE when save_cohorts is enabled.
output$cohort_names = renderTable({updated_names()}, align = 'c', width = "100%")
}
ui <- shinyUI(fluidPage(
sidebarLayout(
sidebarPanel(tableOutput("cohort_names")),
mainPanel(actionButton("run_query", "Run Query"),
actionButton("save_cohort", "Save Cohort"),
actionButton("reset_cohorts", "Reset Cohorts"),
textInput("name_cohort",label= NULL, placeholder = "Enter Cohort Name"))
)
)
)
shinyApp(ui = ui, server = server)