R Shiny 在更改变量选择时更新 DT 中的 textInput 字段
R Shiny update textInput fields' in DT on changing variable selection
我正在构建一个应用程序，用户可以在其中加载 .RData 数据集（可以从 here 下载文件）并从列表 (DT) 中选择变量，移动它到另一个列表（也是 DT），然后可用的因子水平显示在下面的第三个 DT 中。第三个 DT 也有一列动态生成的 textInput 字段，这些字段与变量的可用因子水平数相匹配，用户可以在其中为现有因子水平添加新值。输入的值存储在 reactiveValues 对象中。目前，该对象仅打印在 R 控制台中。该应用程序如下所示：
library(shiny)
library(DT)
library(data.table)
library(shinyFiles)
ui <- fluidPage(
shinyFilesButton(id = "recodeChooseSrcFile", label = "Choose data file", title = "Navigate and select a file", multiple = FALSE),
fluidRow(
column(width = 6,
DTOutput(outputId = "recodeAllAvailableVars"),
),
column(width = 1, align = "center",
br(), br(), br(), br(), br(), br(), br(), br(), br(), br(),
uiOutput(outputId = "recodeArrowSelVarsRight"),
br(), br(),
uiOutput(outputId = "recodeArrowSelVarsLeft"),
),
column(width = 5,
DTOutput(outputId = "recodeVarsSelection"),
),
br(), br()
),
br(), br(),
DTOutput(outputId = "recodeScheme")
)
server <- function(input, output, session) {
available.volumes <- getVolumes()()
file.var.recode <- reactiveValues(loaded = NULL, var.levels = NULL)
# Select file and extract the variables.
shinyFileChoose(input, "recodeChooseSrcFile", roots = available.volumes, filetype = list(RData = "RData"))
observeEvent(eventExpr = input$recodeChooseSrcFile, {
if(length(parseFilePaths(available.volumes, input$recodeChooseSrcFile)$datapath) > 0) {
file.var.recode$loaded <- get(load(parseFilePaths(available.volumes, input$recodeChooseSrcFile)$datapath))
file.var.recode$var.levels <- Filter(Negate(is.null), lapply(X = file.var.recode$loaded, FUN = function(i) {
if(is.null(attr(x = i, which = "levels"))) {
NULL
} else {
attr(x = i, which = "levels")
}
}))
file.var.recode$loaded <- data.table(Variables = names(file.var.recode$loaded),
order_col = 1:ncol(file.var.recode$loaded))
}
}, ignoreInit = TRUE)
observe({
var.props.initial.available.vars <- data.table(Variables = as.character(), order_col = as.numeric())
var.props.initial.selected.vars <- data.table(Variables = as.character(), order_col = as.numeric())
recodeAllVars <- reactiveValues(recodeAvailVars = var.props.initial.available.vars, recodeSelectedVars = var.props.initial.selected.vars)
# Observe if the file is loaded, and if yes, update the table of available variables.
observe({
if(!is.null(file.var.recode$loaded)) {
recodeAllVars$recodeAvailVars <- file.var.recode$loaded
}
})
# Render the arrow buttons for selecting the variables.
output$recodeArrowSelVarsRight <- renderUI({
if(is.null(file.var.recode$loaded)) {
return(NULL)
} else {
actionButton(inputId = "recodeArrowSelVarsRight", label = NULL, icon("angle-right"), width = "50px")
}
})
output$recodeArrowSelVarsLeft <- renderUI({
if(is.null(file.var.recode$loaded)) {
return(NULL)
} else {
actionButton(inputId = "recodeArrowSelVarsLeft", label = NULL, icon("angle-left"), width = "50px")
}
})
# Render the data table with the available variables.
output$recodeAllAvailableVars <- renderDT({
if(is.null(file.var.recode$loaded)) {
return(NULL)
} else {
setkeyv(x = recodeAllVars$recodeAvailVars, cols = "order_col")
}
},
caption = "Available variables",
rownames = FALSE,
colnames = c("Names", "sortingcol"),
options = list(
ordering = FALSE,
columnDefs = list(list(visible = FALSE, targets = 1))
))
# Render the table with the selected variables.
output$recodeVarsSelection <- renderDT({
if(is.null(file.var.recode$loaded)) {
return(NULL)
} else {
setkeyv(x = recodeAllVars$recodeSelectedVars, cols = "order_col")
}
},
caption = "Available variables",
rownames = FALSE,
colnames = c("Names", "sortingcol"),
options = list(
ordering = FALSE,
columnDefs = list(list(visible = FALSE, targets = 1))
))
# Observe the events of moving variables from available to selected.
observeEvent(input$recodeArrowSelVarsRight, {
req(input$recodeAllAvailableVars_rows_selected)
recodeAllVars$recodeSelectedVars <- rbind(isolate(recodeAllVars$recodeSelectedVars), recodeAllVars$recodeAvailVars[input$recodeAllAvailableVars_rows_selected, , drop = F])
recodeAllVars$recodeSelectedVars <- recodeAllVars$recodeSelectedVars[complete.cases(recodeAllVars$recodeSelectedVars[ , "Variables"]), , drop = FALSE]
recodeAllVars$recodeAvailVars <- isolate(recodeAllVars$recodeAvailVars[-input$recodeAllAvailableVars_rows_selected, , drop = F])
})
observeEvent(input$recodeArrowSelVarsLeft, {
req(input$recodeVarsSelection_rows_selected)
recodeAllVars$recodeAvailVars <- rbind(isolate(recodeAllVars$recodeAvailVars), recodeAllVars$recodeSelectedVars[input$recodeVarsSelection_rows_selected, , drop = F])
recodeAllVars$recodeAvailVars <- recodeAllVars$recodeAvailVars[complete.cases(recodeAllVars$recodeAvailVars[ , "Variables"]), , drop = FALSE]
recodeAllVars$recodeSelectedVars <- isolate(recodeAllVars$recodeSelectedVars[-input$recodeVarsSelection_rows_selected, , drop = F])
})
# Render the table with the text inputs.
initial.recode.new.values <- reactiveValues(values = NULL)
entered.new.values <- reactiveValues(values = NULL)
new.recoding.values <- reactiveValues(values = NULL)
shinyInput <- function(obj) {
tmp <- unlist(lapply(X = seq_along(obj), FUN = function(i) {
i <- paste0(textInput(inputId = paste0("numinp", i), label = NULL, value = NULL, width = "50px"))
}))
return(tmp)
}
shinyValue <- function(id, len) {
unlist(lapply(seq_len(len), function(i) {
input[[paste0(id, i)]]
}))
}
# Observe the changes in user selection and update the reactive values from above.
observe({
initial.recode.new.values$values <- unlist(unique(file.var.recode$var.levels[recodeAllVars$recodeSelectedVars[ , Variables]]))
entered.new.values$values <- data.table(
V1 = initial.recode.new.values$values,
V2 = initial.recode.new.values$values,
V3 = rep(x = "->", times = length(initial.recode.new.values$values)),
V4 = shinyInput(unlist(unique(file.var.recode$var.levels[recodeAllVars$recodeSelectedVars[ , Variables]])))
)
new.recoding.values$values <- shinyValue(id = "numinp", len = length(unlist(unique(file.var.recode$var.levels[recodeAllVars$recodeSelectedVars[ , Variables]]))))
})
# Render the table with available levels and empty input fields where the user can enter his desired new values.
output$recodeScheme <- renderDT({
if(!is.null(unlist(unique(file.var.recode$var.levels[recodeAllVars$recodeSelectedVars[ , Variables]])))) {
entered.new.values$values
} else {
return(NULL)
}
},
rownames = FALSE,
colnames = c("Available variable values", "Old", "->", "New"),
class = "cell-border stripe;compact cell-border;",
selection="none",
escape = FALSE,
options = list(
pageLength = 1500,
dom = 'BRrt',
rowCallback = JS("function(r,d) {$(r).attr('height', '40px')}"),
preDrawCallback = JS('function() { Shiny.unbindAll(this.api().table().node()); }'),
drawCallback = JS('function() { Shiny.bindAll(this.api().table().node()); } ')))
observe({
print(new.recoding.values$values)
})
})
}
shinyApp(ui, server)
选择变量时一切正常，新输入的值会立即更新并在每次击键时显示在控制台中。但是，如果用户决定从所选变量的 DT 中删除变量，则 new.recoding.values$values 反应值立即变为 NULL （如预期的那样），但是当另一个变量添加到 DT 的选定变量，前一个变量的旧值将立即返回并且永远不会更新。另外，如果新变量的层数比第一个输入的多，那么最后一个可以更新，而以前的则不行（试试输入ASBG03，然后换成ASBG04看看我均值）。
我真的不明白为什么会这样。到目前为止我尝试的是明确地将 new.recoding.values$values 设置为 NULL in:
1.The观察者生成的地方，在shinyValue函数之前是运行.
2.In observeEvent 右箭头按钮被按下的地方，即：
observeEvent(input$recodeArrowSelVarsLeft, {
req(input$recodeVarsSelection_rows_selected)
recodeAllVars$recodeAvailVars <- rbind(isolate(recodeAllVars$recodeAvailVars),
recodeAllVars$recodeSelectedVars[input$recodeVarsSelection_rows_selected, , drop = F])
recodeAllVars$recodeAvailVars <- recodeAllVars$recodeAvailVars[complete.cases(recodeAllVars$recodeAvailVars[ , "Variables"]), , drop = FALSE]
recodeAllVars$recodeSelectedVars <- isolate(recodeAllVars$recodeSelectedVars[-input$recodeVarsSelection_rows_selected, , drop = F])
new.recoding.values$values <- NULL
})
更新：
3.Following Tonio Lieb运行d 的建议，我尝试按如下方式更新文本输入（在渲染最后一个 DT 之后添加）：
observe({
if(nrow(entered.new.values$values) == 0) {
lapply(seq_len(length(unlist(unique(file.var.recode$var.levels[recodeAllVars$recodeSelectedVars[ , Variables]])))), function(i) {
updateTextInput(session,
input[[paste0("numinp", i)]],
value = NULL,
label = NULL)
})
}
})
None 其中有帮助。每次我删除最初选择的变量时，new.recoding.values$values 在控制台中打印为 NULL，但随后添加另一个变量 new.recoding.values$values 突然恢复第一个输入的第一个值，就像它仍然“记住”第一个输入。
我真的不明白这种行为有人可以帮助克服这个问题，即真正更新变量变化吗？
因为 textFields 是在 datatable 中创建的，您需要在再次使用 table 之前解除绑定（updateTextInput 不起作用）。使用 this 回答中的代码，我添加了带有 unbind 函数的 JS 脚本，并且在左箭头的观察器中调用了该函数。然后你得到一个工作的应用程序：
library(shiny)
library(DT)
library(data.table)
library(shinyFiles)
ui <- fluidPage(
tags$head(tags$script(
HTML(
"Shiny.addCustomMessageHandler('unbindDT', function(id) {
var $table = $('#'+id).find('table');
if($table.length > 0){
Shiny.unbindAll($table.DataTable().table().node());
}
})")
)),
shinyFilesButton(id = "recodeChooseSrcFile", label = "Choose data file", title = "Navigate and select a file", multiple = FALSE),
fluidRow(
column(width = 6,
DTOutput(outputId = "recodeAllAvailableVars"),
),
column(width = 1, align = "center",
br(), br(), br(), br(), br(), br(), br(), br(), br(), br(),
uiOutput(outputId = "recodeArrowSelVarsRight"),
br(), br(),
uiOutput(outputId = "recodeArrowSelVarsLeft"),
),
column(width = 5,
DTOutput(outputId = "recodeVarsSelection"),
),
br(), br()
),
br(), br(),
DTOutput(outputId = "recodeScheme")
)
server <- function(input, output, session) {
available.volumes <- getVolumes()()
file.var.recode <- reactiveValues(loaded = NULL, var.levels = NULL)
# Select file and extract the variables.
shinyFileChoose(input, "recodeChooseSrcFile", roots = available.volumes, filetype = list(RData = "RData"))
observeEvent(eventExpr = input$recodeChooseSrcFile, {
if(length(parseFilePaths(available.volumes, input$recodeChooseSrcFile)$datapath) > 0) {
file.var.recode$loaded <- get(load(parseFilePaths(available.volumes, input$recodeChooseSrcFile)$datapath))
file.var.recode$var.levels <- Filter(Negate(is.null), lapply(X = file.var.recode$loaded, FUN = function(i) {
if(is.null(attr(x = i, which = "levels"))) {
NULL
} else {
attr(x = i, which = "levels")
}
}))
file.var.recode$loaded <- data.table(Variables = names(file.var.recode$loaded),
order_col = 1:ncol(file.var.recode$loaded))
}
}, ignoreInit = TRUE)
observe({
var.props.initial.available.vars <- data.table(Variables = as.character(), order_col = as.numeric())
var.props.initial.selected.vars <- data.table(Variables = as.character(), order_col = as.numeric())
recodeAllVars <- reactiveValues(recodeAvailVars = var.props.initial.available.vars, recodeSelectedVars = var.props.initial.selected.vars)
# Observe if the file is loaded, and if yes, update the table of available variables.
observe({
if(!is.null(file.var.recode$loaded)) {
recodeAllVars$recodeAvailVars <- file.var.recode$loaded
}
})
# Render the arrow buttons for selecting the variables.
output$recodeArrowSelVarsRight <- renderUI({
if(is.null(file.var.recode$loaded)) {
return(NULL)
} else {
actionButton(inputId = "recodeArrowSelVarsRight", label = NULL, icon("angle-right"), width = "50px")
}
})
output$recodeArrowSelVarsLeft <- renderUI({
if(is.null(file.var.recode$loaded)) {
return(NULL)
} else {
actionButton(inputId = "recodeArrowSelVarsLeft", label = NULL, icon("angle-left"), width = "50px")
}
})
# Render the data table with the available variables.
output$recodeAllAvailableVars <- renderDT({
if(is.null(file.var.recode$loaded)) {
return(NULL)
} else {
setkeyv(x = recodeAllVars$recodeAvailVars, cols = "order_col")
}
},
caption = "Available variables",
rownames = FALSE,
colnames = c("Names", "sortingcol"),
options = list(
ordering = FALSE,
columnDefs = list(list(visible = FALSE, targets = 1))
))
# Render the table with the selected variables.
output$recodeVarsSelection <- renderDT({
if(is.null(file.var.recode$loaded)) {
return(NULL)
} else {
setkeyv(x = recodeAllVars$recodeSelectedVars, cols = "order_col")
}
},
caption = "Available variables",
rownames = FALSE,
colnames = c("Names", "sortingcol"),
options = list(
ordering = FALSE,
columnDefs = list(list(visible = FALSE, targets = 1))
))
# Observe the events of moving variables from available to selected.
observeEvent(input$recodeArrowSelVarsRight, {
req(input$recodeAllAvailableVars_rows_selected)
recodeAllVars$recodeSelectedVars <- rbind(isolate(recodeAllVars$recodeSelectedVars), recodeAllVars$recodeAvailVars[input$recodeAllAvailableVars_rows_selected, , drop = F])
recodeAllVars$recodeSelectedVars <- recodeAllVars$recodeSelectedVars[complete.cases(recodeAllVars$recodeSelectedVars[ , "Variables"]), , drop = FALSE]
recodeAllVars$recodeAvailVars <- isolate(recodeAllVars$recodeAvailVars[-input$recodeAllAvailableVars_rows_selected, , drop = F])
})
observeEvent(input$recodeArrowSelVarsLeft, {
req(input$recodeVarsSelection_rows_selected)
recodeAllVars$recodeAvailVars <- rbind(isolate(recodeAllVars$recodeAvailVars), recodeAllVars$recodeSelectedVars[input$recodeVarsSelection_rows_selected, , drop = F])
recodeAllVars$recodeAvailVars <- recodeAllVars$recodeAvailVars[complete.cases(recodeAllVars$recodeAvailVars[ , "Variables"]), , drop = FALSE]
recodeAllVars$recodeSelectedVars <- isolate(recodeAllVars$recodeSelectedVars[-input$recodeVarsSelection_rows_selected, , drop = F])
session$sendCustomMessage("unbindDT", "recodeScheme")
})
# Render the table with the text inputs.
initial.recode.new.values <- reactiveValues(values = NULL)
entered.new.values <- reactiveValues(values = NULL)
new.recoding.values <- reactiveValues(values = NULL)
shinyInput <- function(obj) {
tmp <- unlist(lapply(X = seq_along(obj), FUN = function(i) {
i <- paste0(textInput(inputId = paste0("numinp", i), label = NULL, value = NULL, width = "50px"))
}))
return(tmp)
}
shinyValue <- function(id, len) {
unlist(lapply(seq_len(len), function(i) {
input[[paste0(id, i)]]
}))
}
# Observe the changes in user selection and update the reactive values from above.
observe({
initial.recode.new.values$values <- unlist(unique(file.var.recode$var.levels[recodeAllVars$recodeSelectedVars[ , Variables]]))
entered.new.values$values <- data.table(
V1 = initial.recode.new.values$values,
V2 = initial.recode.new.values$values,
V3 = rep(x = "->", times = length(initial.recode.new.values$values)),
V4 = shinyInput(unlist(unique(file.var.recode$var.levels[recodeAllVars$recodeSelectedVars[ , Variables]])))
)
new.recoding.values$values <- shinyValue(id = "numinp", len = length(unlist(unique(file.var.recode$var.levels[recodeAllVars$recodeSelectedVars[ , Variables]]))))
})
# Render the table with available levels and empty input fields where the user can enter his desired new values.
output$recodeScheme <- renderDT({
if(!is.null(unlist(unique(file.var.recode$var.levels[recodeAllVars$recodeSelectedVars[ , Variables]])))) {
entered.new.values$values
} else {
return(NULL)
}
},
rownames = FALSE,
colnames = c("Available variable values", "Old", "->", "New"),
class = "cell-border stripe;compact cell-border;",
selection="none",
escape = FALSE,
options = list(
pageLength = 1500,
dom = 'BRrt',
rowCallback = JS("function(r,d) {$(r).attr('height', '40px')}"),
preDrawCallback = JS('function() { Shiny.unbindAll(this.api().table().node()); }'),
drawCallback = JS('function() { Shiny.bindAll(this.api().table().node()); } ')))
observe({
print(new.recoding.values$values)
})
})
}
shinyApp(ui, server)
但是，我建议您阅读更多关于反应性的内容，例如here。你使用了很多观察者，并且嵌套了它们。我不推荐这样做，因为这会导致奇怪的行为。此外，请尝试使用更多 reactive/reactiveExpression，因为 observe/observeEvent 会使您的应用变慢。在找到正确的解决方案之前，我尝试稍微取消嵌套您的代码，但它仍然有效！这表明您的应用中存在您实际上不需要的复杂性：
library(shiny)
library(DT)
library(data.table)
library(shinyFiles)
# additional functions
shinyInput <- function(obj) {
tmp <- unlist(lapply(X = seq_along(obj), FUN = function(i) {
i <- paste0(textInput(inputId = paste0("numinp", i), label = NULL, value = NULL, width = "50px"))
}))
return(tmp)
}
shinyValue <- function(id, len, input) {
unlist(lapply(seq_len(len), function(i) {
input[[paste0(id, i)]]
}))
}
ui <- fluidPage(
tags$head(tags$script(
HTML(
"Shiny.addCustomMessageHandler('unbindDT', function(id) {
var $table = $('#'+id).find('table');
if($table.length > 0){
Shiny.unbindAll($table.DataTable().table().node());
}
})")
)),
shinyFilesButton(id = "recodeChooseSrcFile", label = "Choose data file", title = "Navigate and select a file", multiple = FALSE),
fluidRow(
column(width = 6,
DTOutput(outputId = "recodeAllAvailableVars"),
),
column(width = 1, align = "center",
br(), br(), br(), br(), br(), br(), br(), br(), br(), br(),
uiOutput(outputId = "recodeArrowSelVarsRight"),
br(), br(),
uiOutput(outputId = "recodeArrowSelVarsLeft"),
),
column(width = 5,
DTOutput(outputId = "recodeVarsSelection"),
),
br(), br()
),
br(), br(),
DTOutput(outputId = "recodeScheme")
)
server <- function(input, output, session) {
available.volumes <- getVolumes()()
file.var.recode <- reactiveValues(loaded = NULL, var.levels = NULL)
# define variables
# Render the table with the text inputs.
initial.recode.new.values <- reactiveValues(values = NULL)
entered.new.values <- reactiveValues(values = NULL)
new.recoding.values <- reactiveValues(values = NULL)
# Select file and extract the variables.
shinyFileChoose(input, "recodeChooseSrcFile", roots = available.volumes, filetype = list(RData = "RData"))
observeEvent(eventExpr = input$recodeChooseSrcFile, {
if(length(parseFilePaths(available.volumes, input$recodeChooseSrcFile)$datapath) > 0) {
file.var.recode$loaded <- get(load(parseFilePaths(available.volumes, input$recodeChooseSrcFile)$datapath))
file.var.recode$var.levels <- Filter(Negate(is.null), lapply(X = file.var.recode$loaded, FUN = function(i) {
if(is.null(attr(x = i, which = "levels"))) {
NULL
} else {
attr(x = i, which = "levels")
}
}))
file.var.recode$loaded <- data.table(Variables = names(file.var.recode$loaded),
order_col = 1:ncol(file.var.recode$loaded))
}
}, ignoreInit = TRUE)
recodeAllVars <- reactiveValues(recodeAvailVars = data.table(Variables = as.character(), order_col = as.numeric()),
recodeSelectedVars = data.table(Variables = as.character(), order_col = as.numeric()))
# Observe if the file is loaded, and if yes, update the table of available variables.
observe({
if(!is.null(file.var.recode$loaded)) {
recodeAllVars$recodeAvailVars <- file.var.recode$loaded
}
})
# Render the arrow buttons for selecting the variables.
output$recodeArrowSelVarsRight <- renderUI({
if(is.null(file.var.recode$loaded)) {
return(NULL)
} else {
actionButton(inputId = "recodeArrowSelVarsRight", label = NULL, icon("angle-right"), width = "50px")
}
})
output$recodeArrowSelVarsLeft <- renderUI({
if(is.null(file.var.recode$loaded)) {
return(NULL)
} else {
actionButton(inputId = "recodeArrowSelVarsLeft", label = NULL, icon("angle-left"), width = "50px")
}
})
# Render the data table with the available variables.
output$recodeAllAvailableVars <- renderDT({
if(is.null(file.var.recode$loaded)) {
return(NULL)
} else {
setkeyv(x = recodeAllVars$recodeAvailVars, cols = "order_col")
}
},
caption = "Available variables",
rownames = FALSE,
colnames = c("Names", "sortingcol"),
options = list(
ordering = FALSE,
columnDefs = list(list(visible = FALSE, targets = 1))
))
# Render the table with the selected variables.
output$recodeVarsSelection <- renderDT({
if(is.null(file.var.recode$loaded)) {
return(NULL)
} else {
setkeyv(x = recodeAllVars$recodeSelectedVars, cols = "order_col")
}
},
caption = "Available variables",
rownames = FALSE,
colnames = c("Names", "sortingcol"),
options = list(
ordering = FALSE,
columnDefs = list(list(visible = FALSE, targets = 1))
))
# Observe the events of moving variables from available to selected.
observeEvent(input$recodeArrowSelVarsRight, {
req(input$recodeAllAvailableVars_rows_selected)
recodeAllVars$recodeSelectedVars <- rbind(isolate(recodeAllVars$recodeSelectedVars), recodeAllVars$recodeAvailVars[input$recodeAllAvailableVars_rows_selected, , drop = F])
recodeAllVars$recodeSelectedVars <- recodeAllVars$recodeSelectedVars[complete.cases(recodeAllVars$recodeSelectedVars[ , "Variables"]), , drop = FALSE]
recodeAllVars$recodeAvailVars <- isolate(recodeAllVars$recodeAvailVars[-input$recodeAllAvailableVars_rows_selected, , drop = F])
})
observeEvent(input$recodeArrowSelVarsLeft, {
req(input$recodeVarsSelection_rows_selected)
recodeAllVars$recodeAvailVars <- rbind(isolate(recodeAllVars$recodeAvailVars), recodeAllVars$recodeSelectedVars[input$recodeVarsSelection_rows_selected, , drop = F])
recodeAllVars$recodeAvailVars <- recodeAllVars$recodeAvailVars[complete.cases(recodeAllVars$recodeAvailVars[ , "Variables"]), , drop = FALSE]
recodeAllVars$recodeSelectedVars <- isolate(recodeAllVars$recodeSelectedVars[-input$recodeVarsSelection_rows_selected, , drop = F])
session$sendCustomMessage("unbindDT", "recodeScheme")
})
# Observe the changes in user selection and update the reactive values from above.
observe({
initial.recode.new.values$values <- unlist(unique(file.var.recode$var.levels[recodeAllVars$recodeSelectedVars[ , Variables]]))
entered.new.values$values <- data.table(
V1 = initial.recode.new.values$values,
V2 = initial.recode.new.values$values,
V3 = rep(x = "->", times = length(initial.recode.new.values$values)),
V4 = shinyInput(unlist(unique(file.var.recode$var.levels[recodeAllVars$recodeSelectedVars[ , Variables]])))
)
new.recoding.values$values <- shinyValue(id = "numinp",
len = length(unlist(unique(file.var.recode$var.levels[recodeAllVars$recodeSelectedVars[ , Variables]]))),
input = input)
})
# Render the table with available levels and empty input fields where the user can enter his desired new values.
output$recodeScheme <- renderDT({
if(!is.null(unlist(unique(file.var.recode$var.levels[recodeAllVars$recodeSelectedVars[ , Variables]])))) {
entered.new.values$values
} else {
return(NULL)
}
},
rownames = FALSE,
colnames = c("Available variable values", "Old", "->", "New"),
class = "cell-border stripe;compact cell-border;",
selection="none",
escape = FALSE,
options = list(
pageLength = 1500,
dom = 'BRrt',
rowCallback = JS("function(r,d) {$(r).attr('height', '40px')}"),
preDrawCallback = JS('function() { Shiny.unbindAll(this.api().table().node()); }'),
drawCallback = JS('function() { Shiny.bindAll(this.api().table().node()); } ')))
observe({
print(new.recoding.values$values)
})
# end of server
}
shinyApp(ui, server)
还有一些改进的空间，例如您可以尝试对以下代码段使用 reactive 而不是 observe：
# Observe if the file is loaded, and if yes, update the table of available variables.
observe({
if(!is.null(file.var.recode$loaded)) {
recodeAllVars$recodeAvailVars <- file.var.recode$loaded
}
})
我正在构建一个应用程序，用户可以在其中加载 .RData 数据集（可以从 here 下载文件）并从列表 (DT) 中选择变量，移动它到另一个列表（也是 DT），然后可用的因子水平显示在下面的第三个 DT 中。第三个 DT 也有一列动态生成的 textInput 字段，这些字段与变量的可用因子水平数相匹配，用户可以在其中为现有因子水平添加新值。输入的值存储在 reactiveValues 对象中。目前，该对象仅打印在 R 控制台中。该应用程序如下所示：
library(shiny)
library(DT)
library(data.table)
library(shinyFiles)
ui <- fluidPage(
shinyFilesButton(id = "recodeChooseSrcFile", label = "Choose data file", title = "Navigate and select a file", multiple = FALSE),
fluidRow(
column(width = 6,
DTOutput(outputId = "recodeAllAvailableVars"),
),
column(width = 1, align = "center",
br(), br(), br(), br(), br(), br(), br(), br(), br(), br(),
uiOutput(outputId = "recodeArrowSelVarsRight"),
br(), br(),
uiOutput(outputId = "recodeArrowSelVarsLeft"),
),
column(width = 5,
DTOutput(outputId = "recodeVarsSelection"),
),
br(), br()
),
br(), br(),
DTOutput(outputId = "recodeScheme")
)
server <- function(input, output, session) {
available.volumes <- getVolumes()()
file.var.recode <- reactiveValues(loaded = NULL, var.levels = NULL)
# Select file and extract the variables.
shinyFileChoose(input, "recodeChooseSrcFile", roots = available.volumes, filetype = list(RData = "RData"))
observeEvent(eventExpr = input$recodeChooseSrcFile, {
if(length(parseFilePaths(available.volumes, input$recodeChooseSrcFile)$datapath) > 0) {
file.var.recode$loaded <- get(load(parseFilePaths(available.volumes, input$recodeChooseSrcFile)$datapath))
file.var.recode$var.levels <- Filter(Negate(is.null), lapply(X = file.var.recode$loaded, FUN = function(i) {
if(is.null(attr(x = i, which = "levels"))) {
NULL
} else {
attr(x = i, which = "levels")
}
}))
file.var.recode$loaded <- data.table(Variables = names(file.var.recode$loaded),
order_col = 1:ncol(file.var.recode$loaded))
}
}, ignoreInit = TRUE)
observe({
var.props.initial.available.vars <- data.table(Variables = as.character(), order_col = as.numeric())
var.props.initial.selected.vars <- data.table(Variables = as.character(), order_col = as.numeric())
recodeAllVars <- reactiveValues(recodeAvailVars = var.props.initial.available.vars, recodeSelectedVars = var.props.initial.selected.vars)
# Observe if the file is loaded, and if yes, update the table of available variables.
observe({
if(!is.null(file.var.recode$loaded)) {
recodeAllVars$recodeAvailVars <- file.var.recode$loaded
}
})
# Render the arrow buttons for selecting the variables.
output$recodeArrowSelVarsRight <- renderUI({
if(is.null(file.var.recode$loaded)) {
return(NULL)
} else {
actionButton(inputId = "recodeArrowSelVarsRight", label = NULL, icon("angle-right"), width = "50px")
}
})
output$recodeArrowSelVarsLeft <- renderUI({
if(is.null(file.var.recode$loaded)) {
return(NULL)
} else {
actionButton(inputId = "recodeArrowSelVarsLeft", label = NULL, icon("angle-left"), width = "50px")
}
})
# Render the data table with the available variables.
output$recodeAllAvailableVars <- renderDT({
if(is.null(file.var.recode$loaded)) {
return(NULL)
} else {
setkeyv(x = recodeAllVars$recodeAvailVars, cols = "order_col")
}
},
caption = "Available variables",
rownames = FALSE,
colnames = c("Names", "sortingcol"),
options = list(
ordering = FALSE,
columnDefs = list(list(visible = FALSE, targets = 1))
))
# Render the table with the selected variables.
output$recodeVarsSelection <- renderDT({
if(is.null(file.var.recode$loaded)) {
return(NULL)
} else {
setkeyv(x = recodeAllVars$recodeSelectedVars, cols = "order_col")
}
},
caption = "Available variables",
rownames = FALSE,
colnames = c("Names", "sortingcol"),
options = list(
ordering = FALSE,
columnDefs = list(list(visible = FALSE, targets = 1))
))
# Observe the events of moving variables from available to selected.
observeEvent(input$recodeArrowSelVarsRight, {
req(input$recodeAllAvailableVars_rows_selected)
recodeAllVars$recodeSelectedVars <- rbind(isolate(recodeAllVars$recodeSelectedVars), recodeAllVars$recodeAvailVars[input$recodeAllAvailableVars_rows_selected, , drop = F])
recodeAllVars$recodeSelectedVars <- recodeAllVars$recodeSelectedVars[complete.cases(recodeAllVars$recodeSelectedVars[ , "Variables"]), , drop = FALSE]
recodeAllVars$recodeAvailVars <- isolate(recodeAllVars$recodeAvailVars[-input$recodeAllAvailableVars_rows_selected, , drop = F])
})
observeEvent(input$recodeArrowSelVarsLeft, {
req(input$recodeVarsSelection_rows_selected)
recodeAllVars$recodeAvailVars <- rbind(isolate(recodeAllVars$recodeAvailVars), recodeAllVars$recodeSelectedVars[input$recodeVarsSelection_rows_selected, , drop = F])
recodeAllVars$recodeAvailVars <- recodeAllVars$recodeAvailVars[complete.cases(recodeAllVars$recodeAvailVars[ , "Variables"]), , drop = FALSE]
recodeAllVars$recodeSelectedVars <- isolate(recodeAllVars$recodeSelectedVars[-input$recodeVarsSelection_rows_selected, , drop = F])
})
# Render the table with the text inputs.
initial.recode.new.values <- reactiveValues(values = NULL)
entered.new.values <- reactiveValues(values = NULL)
new.recoding.values <- reactiveValues(values = NULL)
shinyInput <- function(obj) {
tmp <- unlist(lapply(X = seq_along(obj), FUN = function(i) {
i <- paste0(textInput(inputId = paste0("numinp", i), label = NULL, value = NULL, width = "50px"))
}))
return(tmp)
}
shinyValue <- function(id, len) {
unlist(lapply(seq_len(len), function(i) {
input[[paste0(id, i)]]
}))
}
# Observe the changes in user selection and update the reactive values from above.
observe({
initial.recode.new.values$values <- unlist(unique(file.var.recode$var.levels[recodeAllVars$recodeSelectedVars[ , Variables]]))
entered.new.values$values <- data.table(
V1 = initial.recode.new.values$values,
V2 = initial.recode.new.values$values,
V3 = rep(x = "->", times = length(initial.recode.new.values$values)),
V4 = shinyInput(unlist(unique(file.var.recode$var.levels[recodeAllVars$recodeSelectedVars[ , Variables]])))
)
new.recoding.values$values <- shinyValue(id = "numinp", len = length(unlist(unique(file.var.recode$var.levels[recodeAllVars$recodeSelectedVars[ , Variables]]))))
})
# Render the table with available levels and empty input fields where the user can enter his desired new values.
output$recodeScheme <- renderDT({
if(!is.null(unlist(unique(file.var.recode$var.levels[recodeAllVars$recodeSelectedVars[ , Variables]])))) {
entered.new.values$values
} else {
return(NULL)
}
},
rownames = FALSE,
colnames = c("Available variable values", "Old", "->", "New"),
class = "cell-border stripe;compact cell-border;",
selection="none",
escape = FALSE,
options = list(
pageLength = 1500,
dom = 'BRrt',
rowCallback = JS("function(r,d) {$(r).attr('height', '40px')}"),
preDrawCallback = JS('function() { Shiny.unbindAll(this.api().table().node()); }'),
drawCallback = JS('function() { Shiny.bindAll(this.api().table().node()); } ')))
observe({
print(new.recoding.values$values)
})
})
}
shinyApp(ui, server)
选择变量时一切正常，新输入的值会立即更新并在每次击键时显示在控制台中。但是，如果用户决定从所选变量的 DT 中删除变量，则 new.recoding.values$values 反应值立即变为 NULL （如预期的那样），但是当另一个变量添加到 DT 的选定变量，前一个变量的旧值将立即返回并且永远不会更新。另外，如果新变量的层数比第一个输入的多，那么最后一个可以更新，而以前的则不行（试试输入ASBG03，然后换成ASBG04看看我均值）。
我真的不明白为什么会这样。到目前为止我尝试的是明确地将 new.recoding.values$values 设置为 NULL in:
1.The观察者生成的地方，在shinyValue函数之前是运行.
2.In observeEvent 右箭头按钮被按下的地方，即：
observeEvent(input$recodeArrowSelVarsLeft, {
req(input$recodeVarsSelection_rows_selected)
recodeAllVars$recodeAvailVars <- rbind(isolate(recodeAllVars$recodeAvailVars),
recodeAllVars$recodeSelectedVars[input$recodeVarsSelection_rows_selected, , drop = F])
recodeAllVars$recodeAvailVars <- recodeAllVars$recodeAvailVars[complete.cases(recodeAllVars$recodeAvailVars[ , "Variables"]), , drop = FALSE]
recodeAllVars$recodeSelectedVars <- isolate(recodeAllVars$recodeSelectedVars[-input$recodeVarsSelection_rows_selected, , drop = F])
new.recoding.values$values <- NULL
})
更新：
3.Following Tonio Lieb运行d 的建议，我尝试按如下方式更新文本输入（在渲染最后一个 DT 之后添加）：
observe({
if(nrow(entered.new.values$values) == 0) {
lapply(seq_len(length(unlist(unique(file.var.recode$var.levels[recodeAllVars$recodeSelectedVars[ , Variables]])))), function(i) {
updateTextInput(session,
input[[paste0("numinp", i)]],
value = NULL,
label = NULL)
})
}
})
None 其中有帮助。每次我删除最初选择的变量时，new.recoding.values$values 在控制台中打印为 NULL，但随后添加另一个变量 new.recoding.values$values 突然恢复第一个输入的第一个值，就像它仍然“记住”第一个输入。
我真的不明白这种行为有人可以帮助克服这个问题，即真正更新变量变化吗？
因为 textFields 是在 datatable 中创建的，您需要在再次使用 table 之前解除绑定（updateTextInput 不起作用）。使用 this 回答中的代码，我添加了带有 unbind 函数的 JS 脚本，并且在左箭头的观察器中调用了该函数。然后你得到一个工作的应用程序：
library(shiny)
library(DT)
library(data.table)
library(shinyFiles)
ui <- fluidPage(
tags$head(tags$script(
HTML(
"Shiny.addCustomMessageHandler('unbindDT', function(id) {
var $table = $('#'+id).find('table');
if($table.length > 0){
Shiny.unbindAll($table.DataTable().table().node());
}
})")
)),
shinyFilesButton(id = "recodeChooseSrcFile", label = "Choose data file", title = "Navigate and select a file", multiple = FALSE),
fluidRow(
column(width = 6,
DTOutput(outputId = "recodeAllAvailableVars"),
),
column(width = 1, align = "center",
br(), br(), br(), br(), br(), br(), br(), br(), br(), br(),
uiOutput(outputId = "recodeArrowSelVarsRight"),
br(), br(),
uiOutput(outputId = "recodeArrowSelVarsLeft"),
),
column(width = 5,
DTOutput(outputId = "recodeVarsSelection"),
),
br(), br()
),
br(), br(),
DTOutput(outputId = "recodeScheme")
)
server <- function(input, output, session) {
available.volumes <- getVolumes()()
file.var.recode <- reactiveValues(loaded = NULL, var.levels = NULL)
# Select file and extract the variables.
shinyFileChoose(input, "recodeChooseSrcFile", roots = available.volumes, filetype = list(RData = "RData"))
observeEvent(eventExpr = input$recodeChooseSrcFile, {
if(length(parseFilePaths(available.volumes, input$recodeChooseSrcFile)$datapath) > 0) {
file.var.recode$loaded <- get(load(parseFilePaths(available.volumes, input$recodeChooseSrcFile)$datapath))
file.var.recode$var.levels <- Filter(Negate(is.null), lapply(X = file.var.recode$loaded, FUN = function(i) {
if(is.null(attr(x = i, which = "levels"))) {
NULL
} else {
attr(x = i, which = "levels")
}
}))
file.var.recode$loaded <- data.table(Variables = names(file.var.recode$loaded),
order_col = 1:ncol(file.var.recode$loaded))
}
}, ignoreInit = TRUE)
observe({
var.props.initial.available.vars <- data.table(Variables = as.character(), order_col = as.numeric())
var.props.initial.selected.vars <- data.table(Variables = as.character(), order_col = as.numeric())
recodeAllVars <- reactiveValues(recodeAvailVars = var.props.initial.available.vars, recodeSelectedVars = var.props.initial.selected.vars)
# Observe if the file is loaded, and if yes, update the table of available variables.
observe({
if(!is.null(file.var.recode$loaded)) {
recodeAllVars$recodeAvailVars <- file.var.recode$loaded
}
})
# Render the arrow buttons for selecting the variables.
output$recodeArrowSelVarsRight <- renderUI({
if(is.null(file.var.recode$loaded)) {
return(NULL)
} else {
actionButton(inputId = "recodeArrowSelVarsRight", label = NULL, icon("angle-right"), width = "50px")
}
})
output$recodeArrowSelVarsLeft <- renderUI({
if(is.null(file.var.recode$loaded)) {
return(NULL)
} else {
actionButton(inputId = "recodeArrowSelVarsLeft", label = NULL, icon("angle-left"), width = "50px")
}
})
# Render the data table with the available variables.
output$recodeAllAvailableVars <- renderDT({
if(is.null(file.var.recode$loaded)) {
return(NULL)
} else {
setkeyv(x = recodeAllVars$recodeAvailVars, cols = "order_col")
}
},
caption = "Available variables",
rownames = FALSE,
colnames = c("Names", "sortingcol"),
options = list(
ordering = FALSE,
columnDefs = list(list(visible = FALSE, targets = 1))
))
# Render the table with the selected variables.
output$recodeVarsSelection <- renderDT({
if(is.null(file.var.recode$loaded)) {
return(NULL)
} else {
setkeyv(x = recodeAllVars$recodeSelectedVars, cols = "order_col")
}
},
caption = "Available variables",
rownames = FALSE,
colnames = c("Names", "sortingcol"),
options = list(
ordering = FALSE,
columnDefs = list(list(visible = FALSE, targets = 1))
))
# Observe the events of moving variables from available to selected.
observeEvent(input$recodeArrowSelVarsRight, {
req(input$recodeAllAvailableVars_rows_selected)
recodeAllVars$recodeSelectedVars <- rbind(isolate(recodeAllVars$recodeSelectedVars), recodeAllVars$recodeAvailVars[input$recodeAllAvailableVars_rows_selected, , drop = F])
recodeAllVars$recodeSelectedVars <- recodeAllVars$recodeSelectedVars[complete.cases(recodeAllVars$recodeSelectedVars[ , "Variables"]), , drop = FALSE]
recodeAllVars$recodeAvailVars <- isolate(recodeAllVars$recodeAvailVars[-input$recodeAllAvailableVars_rows_selected, , drop = F])
})
observeEvent(input$recodeArrowSelVarsLeft, {
req(input$recodeVarsSelection_rows_selected)
recodeAllVars$recodeAvailVars <- rbind(isolate(recodeAllVars$recodeAvailVars), recodeAllVars$recodeSelectedVars[input$recodeVarsSelection_rows_selected, , drop = F])
recodeAllVars$recodeAvailVars <- recodeAllVars$recodeAvailVars[complete.cases(recodeAllVars$recodeAvailVars[ , "Variables"]), , drop = FALSE]
recodeAllVars$recodeSelectedVars <- isolate(recodeAllVars$recodeSelectedVars[-input$recodeVarsSelection_rows_selected, , drop = F])
session$sendCustomMessage("unbindDT", "recodeScheme")
})
# Render the table with the text inputs.
initial.recode.new.values <- reactiveValues(values = NULL)
entered.new.values <- reactiveValues(values = NULL)
new.recoding.values <- reactiveValues(values = NULL)
shinyInput <- function(obj) {
tmp <- unlist(lapply(X = seq_along(obj), FUN = function(i) {
i <- paste0(textInput(inputId = paste0("numinp", i), label = NULL, value = NULL, width = "50px"))
}))
return(tmp)
}
shinyValue <- function(id, len) {
unlist(lapply(seq_len(len), function(i) {
input[[paste0(id, i)]]
}))
}
# Observe the changes in user selection and update the reactive values from above.
observe({
initial.recode.new.values$values <- unlist(unique(file.var.recode$var.levels[recodeAllVars$recodeSelectedVars[ , Variables]]))
entered.new.values$values <- data.table(
V1 = initial.recode.new.values$values,
V2 = initial.recode.new.values$values,
V3 = rep(x = "->", times = length(initial.recode.new.values$values)),
V4 = shinyInput(unlist(unique(file.var.recode$var.levels[recodeAllVars$recodeSelectedVars[ , Variables]])))
)
new.recoding.values$values <- shinyValue(id = "numinp", len = length(unlist(unique(file.var.recode$var.levels[recodeAllVars$recodeSelectedVars[ , Variables]]))))
})
# Render the table with available levels and empty input fields where the user can enter his desired new values.
output$recodeScheme <- renderDT({
if(!is.null(unlist(unique(file.var.recode$var.levels[recodeAllVars$recodeSelectedVars[ , Variables]])))) {
entered.new.values$values
} else {
return(NULL)
}
},
rownames = FALSE,
colnames = c("Available variable values", "Old", "->", "New"),
class = "cell-border stripe;compact cell-border;",
selection="none",
escape = FALSE,
options = list(
pageLength = 1500,
dom = 'BRrt',
rowCallback = JS("function(r,d) {$(r).attr('height', '40px')}"),
preDrawCallback = JS('function() { Shiny.unbindAll(this.api().table().node()); }'),
drawCallback = JS('function() { Shiny.bindAll(this.api().table().node()); } ')))
observe({
print(new.recoding.values$values)
})
})
}
shinyApp(ui, server)
但是，我建议您阅读更多关于反应性的内容，例如here。你使用了很多观察者，并且嵌套了它们。我不推荐这样做，因为这会导致奇怪的行为。此外，请尝试使用更多 reactive/reactiveExpression，因为 observe/observeEvent 会使您的应用变慢。在找到正确的解决方案之前，我尝试稍微取消嵌套您的代码，但它仍然有效！这表明您的应用中存在您实际上不需要的复杂性：
library(shiny)
library(DT)
library(data.table)
library(shinyFiles)
# additional functions
shinyInput <- function(obj) {
tmp <- unlist(lapply(X = seq_along(obj), FUN = function(i) {
i <- paste0(textInput(inputId = paste0("numinp", i), label = NULL, value = NULL, width = "50px"))
}))
return(tmp)
}
shinyValue <- function(id, len, input) {
unlist(lapply(seq_len(len), function(i) {
input[[paste0(id, i)]]
}))
}
ui <- fluidPage(
tags$head(tags$script(
HTML(
"Shiny.addCustomMessageHandler('unbindDT', function(id) {
var $table = $('#'+id).find('table');
if($table.length > 0){
Shiny.unbindAll($table.DataTable().table().node());
}
})")
)),
shinyFilesButton(id = "recodeChooseSrcFile", label = "Choose data file", title = "Navigate and select a file", multiple = FALSE),
fluidRow(
column(width = 6,
DTOutput(outputId = "recodeAllAvailableVars"),
),
column(width = 1, align = "center",
br(), br(), br(), br(), br(), br(), br(), br(), br(), br(),
uiOutput(outputId = "recodeArrowSelVarsRight"),
br(), br(),
uiOutput(outputId = "recodeArrowSelVarsLeft"),
),
column(width = 5,
DTOutput(outputId = "recodeVarsSelection"),
),
br(), br()
),
br(), br(),
DTOutput(outputId = "recodeScheme")
)
server <- function(input, output, session) {
available.volumes <- getVolumes()()
file.var.recode <- reactiveValues(loaded = NULL, var.levels = NULL)
# define variables
# Render the table with the text inputs.
initial.recode.new.values <- reactiveValues(values = NULL)
entered.new.values <- reactiveValues(values = NULL)
new.recoding.values <- reactiveValues(values = NULL)
# Select file and extract the variables.
shinyFileChoose(input, "recodeChooseSrcFile", roots = available.volumes, filetype = list(RData = "RData"))
observeEvent(eventExpr = input$recodeChooseSrcFile, {
if(length(parseFilePaths(available.volumes, input$recodeChooseSrcFile)$datapath) > 0) {
file.var.recode$loaded <- get(load(parseFilePaths(available.volumes, input$recodeChooseSrcFile)$datapath))
file.var.recode$var.levels <- Filter(Negate(is.null), lapply(X = file.var.recode$loaded, FUN = function(i) {
if(is.null(attr(x = i, which = "levels"))) {
NULL
} else {
attr(x = i, which = "levels")
}
}))
file.var.recode$loaded <- data.table(Variables = names(file.var.recode$loaded),
order_col = 1:ncol(file.var.recode$loaded))
}
}, ignoreInit = TRUE)
recodeAllVars <- reactiveValues(recodeAvailVars = data.table(Variables = as.character(), order_col = as.numeric()),
recodeSelectedVars = data.table(Variables = as.character(), order_col = as.numeric()))
# Observe if the file is loaded, and if yes, update the table of available variables.
observe({
if(!is.null(file.var.recode$loaded)) {
recodeAllVars$recodeAvailVars <- file.var.recode$loaded
}
})
# Render the arrow buttons for selecting the variables.
output$recodeArrowSelVarsRight <- renderUI({
if(is.null(file.var.recode$loaded)) {
return(NULL)
} else {
actionButton(inputId = "recodeArrowSelVarsRight", label = NULL, icon("angle-right"), width = "50px")
}
})
output$recodeArrowSelVarsLeft <- renderUI({
if(is.null(file.var.recode$loaded)) {
return(NULL)
} else {
actionButton(inputId = "recodeArrowSelVarsLeft", label = NULL, icon("angle-left"), width = "50px")
}
})
# Render the data table with the available variables.
output$recodeAllAvailableVars <- renderDT({
if(is.null(file.var.recode$loaded)) {
return(NULL)
} else {
setkeyv(x = recodeAllVars$recodeAvailVars, cols = "order_col")
}
},
caption = "Available variables",
rownames = FALSE,
colnames = c("Names", "sortingcol"),
options = list(
ordering = FALSE,
columnDefs = list(list(visible = FALSE, targets = 1))
))
# Render the table with the selected variables.
output$recodeVarsSelection <- renderDT({
if(is.null(file.var.recode$loaded)) {
return(NULL)
} else {
setkeyv(x = recodeAllVars$recodeSelectedVars, cols = "order_col")
}
},
caption = "Available variables",
rownames = FALSE,
colnames = c("Names", "sortingcol"),
options = list(
ordering = FALSE,
columnDefs = list(list(visible = FALSE, targets = 1))
))
# Observe the events of moving variables from available to selected.
observeEvent(input$recodeArrowSelVarsRight, {
req(input$recodeAllAvailableVars_rows_selected)
recodeAllVars$recodeSelectedVars <- rbind(isolate(recodeAllVars$recodeSelectedVars), recodeAllVars$recodeAvailVars[input$recodeAllAvailableVars_rows_selected, , drop = F])
recodeAllVars$recodeSelectedVars <- recodeAllVars$recodeSelectedVars[complete.cases(recodeAllVars$recodeSelectedVars[ , "Variables"]), , drop = FALSE]
recodeAllVars$recodeAvailVars <- isolate(recodeAllVars$recodeAvailVars[-input$recodeAllAvailableVars_rows_selected, , drop = F])
})
observeEvent(input$recodeArrowSelVarsLeft, {
req(input$recodeVarsSelection_rows_selected)
recodeAllVars$recodeAvailVars <- rbind(isolate(recodeAllVars$recodeAvailVars), recodeAllVars$recodeSelectedVars[input$recodeVarsSelection_rows_selected, , drop = F])
recodeAllVars$recodeAvailVars <- recodeAllVars$recodeAvailVars[complete.cases(recodeAllVars$recodeAvailVars[ , "Variables"]), , drop = FALSE]
recodeAllVars$recodeSelectedVars <- isolate(recodeAllVars$recodeSelectedVars[-input$recodeVarsSelection_rows_selected, , drop = F])
session$sendCustomMessage("unbindDT", "recodeScheme")
})
# Observe the changes in user selection and update the reactive values from above.
observe({
initial.recode.new.values$values <- unlist(unique(file.var.recode$var.levels[recodeAllVars$recodeSelectedVars[ , Variables]]))
entered.new.values$values <- data.table(
V1 = initial.recode.new.values$values,
V2 = initial.recode.new.values$values,
V3 = rep(x = "->", times = length(initial.recode.new.values$values)),
V4 = shinyInput(unlist(unique(file.var.recode$var.levels[recodeAllVars$recodeSelectedVars[ , Variables]])))
)
new.recoding.values$values <- shinyValue(id = "numinp",
len = length(unlist(unique(file.var.recode$var.levels[recodeAllVars$recodeSelectedVars[ , Variables]]))),
input = input)
})
# Render the table with available levels and empty input fields where the user can enter his desired new values.
output$recodeScheme <- renderDT({
if(!is.null(unlist(unique(file.var.recode$var.levels[recodeAllVars$recodeSelectedVars[ , Variables]])))) {
entered.new.values$values
} else {
return(NULL)
}
},
rownames = FALSE,
colnames = c("Available variable values", "Old", "->", "New"),
class = "cell-border stripe;compact cell-border;",
selection="none",
escape = FALSE,
options = list(
pageLength = 1500,
dom = 'BRrt',
rowCallback = JS("function(r,d) {$(r).attr('height', '40px')}"),
preDrawCallback = JS('function() { Shiny.unbindAll(this.api().table().node()); }'),
drawCallback = JS('function() { Shiny.bindAll(this.api().table().node()); } ')))
observe({
print(new.recoding.values$values)
})
# end of server
}
shinyApp(ui, server)
还有一些改进的空间，例如您可以尝试对以下代码段使用 reactive 而不是 observe：
# Observe if the file is loaded, and if yes, update the table of available variables.
observe({
if(!is.null(file.var.recode$loaded)) {
recodeAllVars$recodeAvailVars <- file.var.recode$loaded
}
})