使用shinyWidget保存和加载输入：：updateVirtualSelect()引导闪亮的应用程序崩溃
使用shinyWidget保存和加载输入：：updateVirtualSelect()引导闪亮的应用程序崩溃
提问于 2022-07-25 12:33:39
我正在尝试将shinyWidgets::virtualSelectInput()保存到csv，然后加载csv文件并使用shinyWidgets::updateVirtualSelect().更新选定的输入。
更具体地说，我希望用户选择输入，将输入写入具有用户名的csv文件中，然后选择保存文件并加载保存在其中的输入。
但是，我得到以下错误：
警告: if:参数中的错误长度为零。没有堆栈跟踪可用
应用程序就崩溃了。
下面是一个使用字母的可复制的简单示例：
ui <- shiny::fluidPage(
shinyWidgets::virtualSelectInput(
inputId = "letters",
label = "Letters",
choices = NULL,
selected = NULL,
multiple = TRUE,
search = T,
placeholder = "Select Letters"
),
shiny::inputPanel(
shiny::textInput(
inputId = "savefilename",
label = "File Name",
placeholder = "Name to save file"),
shiny::actionButton(
"saveFile", "Save"
),
shiny::selectInput(
'selectfile','Select File',
choice = list.files(pattern = ".csv")
),
shiny::actionButton(
"loadFile","Load",
)
),
)
server <- function(input,output,session){
observe(
{
shinyWidgets::updateVirtualSelect(
session = session,
inputId = "letters",
label = "Letters",
choices = LETTERS
)
}
)
# Save File
observeEvent(
input$saveFile,
{
LETTERS_table = tibble("LETTERS_picked" = input$letters) %>%
write_csv(file = paste(paste(input$savefilename,"_.csv",sep = ""),sep = ""))
updateSelectInput(
session = session,
inputId = "selectfile",
choices = list.files(pattern = ".csv")
)
}
)
# Load File
observeEvent(
input$loadFile,
{
LETTERS_table = read_csv(file = input$selectfile)
shinyWidgets::updateVirtualSelect(
session,
inputId = "letters",
choices = LETTERS,
selected = as.character(na.omit(LETTERS_table$LETTERS_picked))
)
}
)
}
shinyApp(ui, server)出于技术原因-我不能使用 shinyWidgets::pickerInput
到底怎么回事？我怎么才能解决这个问题？谢谢。
回答 1
Stack Overflow用户
发布于 2022-07-25 13:47:09
请参阅?updateVirtualSelect
updateVirtualSelect(
inputId,
label = NULL,
choices = NULL,
selected = NULL,
disable = NULL,
session = shiny::getDefaultReactiveDomain()
)您需要确保保持函数参数的顺序，或者传递命名的参数。在上面的代码中，您将session作为第一个未命名的参数传递--应该是inputId。
library(shiny)
library(shinyWidgets)
library(readr)
library(tibble)
ui <- shiny::fluidPage(
shinyWidgets::virtualSelectInput(
inputId = "letters",
label = "Letters",
choices = NULL,
selected = NULL,
multiple = TRUE,
search = T,
placeholder = "Select Letters"
),
shiny::inputPanel(
shiny::textInput(
inputId = "savefilename",
label = "File Name",
placeholder = "Name to save file"
),
shiny::actionButton("saveFile", "Save", style = "margin-top: 25px"),
shiny::selectInput('selectfile', 'Select File', choice = list.files(pattern = ".csv")),
shiny::actionButton("loadFile", "Load", style = "margin-top: 25px")
)
)
server <- function(input, output, session) {
shinyWidgets::updateVirtualSelect(
session = session,
inputId = "letters",
label = "Letters",
choices = LETTERS
)
# Save File
observeEvent(input$saveFile,
{
req(input$letters)
LETTERS_table = tibble("LETTERS_picked" = input$letters) %>%
write_csv(file = paste(paste(input$savefilename, "_.csv", sep = ""), sep = ""))
updateSelectInput(
session = session,
inputId = "selectfile",
choices = list.files(pattern = ".csv")
)
})
# Load File
observeEvent(input$loadFile,
{
LETTERS_table = read_csv(file = input$selectfile)
req(NROW(LETTERS_table) > 0)
shinyWidgets::updateVirtualSelect(
inputId = "letters",
choices = LETTERS,
selected = as.character(na.omit(LETTERS_table$LETTERS_picked)),
session = session
)
})
}
shinyApp(ui, server)页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://stackoverflow.com/questions/73109327
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